A Journey to Incredible Exoplanets - A Journey to Our Nearest Stars

to the broiling heat of earth's closest neighbor radical weather is the norm in the solar system we do have our own extremes here on earth but they pale in comparison to the fastest dustiest wettest and most brutal alien storms [Music] on earth the sun drives our weather and sometimes drives it wild when hot and cold collide in the atmosphere watch out this is true locally and globally but storms on other planets are bigger badder and stranger than their counterparts on earth why is that because of the sun if not what else fuels their fury the basic laws of nature the rules of the game are pretty much the same wherever you go in the solar system but every planet has its own way of playing the game right now on mars the entire planet is being covered in dust this global dust storm blocks 99 of the sun's rays from reaching the planet's surface it's actually a system of smaller but still massive storms churning dust high into the atmosphere once it starts it takes months for martian skies to clear mars is just the most dramatic weather in the solar system in some senses it's very rare in the solar system you get a weather event that can take out the whole planet so if the basic rules of hot and cold are the same on mars why is the weather so different from earth for one thing mars is half the size of earth it's also 50 further from the sun so it's much colder the average temperature on mars is minus 80 degrees that's almost 130 degrees colder than earth and the atmosphere is extremely thin and composed mostly of carbon dioxide but perhaps the most important difference is this mars is a global desert what would earth be like without water well you'd probably have a lot of dust there's no liquid water at the surface of mars and there's very little water in the atmosphere and so there's nothing to sort of keep the dust down on earth dust storms are localized and short-lived the reason for that difference in scale is is that the storms are generating their own weather on mars whereas on the earth they're they're slave to the to the weather that's going on around them in other words on earth the global weather system creates dust storms on mars the storms create a global weather system astronomers have always been able to see big martian dust storms easily with earth-based telescopes [Music] but what they couldn't see was what caused them that would require a trip to mars itself in 2003 nasa landed two rovers called spirit and opportunity on the martian surface their mission to learn more about the geology of the red planet nasa engineers always assumed that as these two vehicles roamed the martian surface dust would build up on their solar panels if you have a lot of dust that's falling down out of the atmosphere and coating the panels pretty soon you're not getting much sun to the to the silicon in fact we thought that that was what was going to kill the rover's spirit and opportunity only it never happened the rovers didn't die as expected as dust built up on the panels somehow something would clean them off but how could this be nasa engineers were baffled until the rovers themselves saw the culprit martian dust devils it turns out that dust devils were sort of our our white knight they came along and cleaned off the solar panels just at the time we were expecting to start having some problems there are beautiful photos that actually show dust devils moving across the martian atmosphere and ghostly soldiers moving out there in the distance a dust devil is really an extreme form of rising hot air or convection and that hot air wants to go up and it comes up just like you know water going down a drain well this is air that just spirals up into the colder parts of the atmosphere whenever warmer air which is less dense rises up through cooler air which is more dense it rotates as it swirls upwards convection can be very powerful strong enough to lift things up on earth it lifts moisture and that's how thunderstorms form but on mars there is no moisture so it lifts dry dark dust and creates giant dust storms instead once airborne martian dust clouds absorb sunlight and heat the atmosphere this supercharges the convection lifting still more dust that produces more winds which bring up more dust and these things can spread up to thousands of miles across or even in some cases they can envelop the entire planet and because the martian atmosphere is so thin it doesn't take much to get this cycle going you get a lot more difference between the surface temperature and the air temperature and so the convection on mars is very much more vigorous as a rule earth doesn't get the temperature extremes that mars does but sometimes here and there in the deserts of earth convection can be very martian like we get dust devils too but at arizona state university lynn necres makes dust devils to order in a lab to study them up close he uses a vortex generator and substitutes lighter dry ice for dust what he creates is not an exact replica of how real dust devils form but good enough to see how they pick up dust and debris natural dust devils usually form from the bottom up as opposed to tornadoes which form from top down so what happens when we when we turn this on we have the air flow starting and as the airflow starts to rotate from the fans down to the floor we actually end up having the vortex form in other words the vortex generator basically a huge vacuum cleaner imitates the swirling action of convection you can see here there's a wider base where larger particles of the dry ice are being swept up and gets wrapped up and tightens as it expands upward the center of the core is where the majority of the lifting would occur martian dust devils have been helpful keeping the rovers clean but could they actually be making a mess of the rest of the planet some scientists think there are so many at any one time and they lift so much dust into the atmosphere that together they trigger these much larger dust storms it starts wind patterns and the air is warmer over here and it's colder over here and the air starts moving around pretty soon you're spreading dust over the whole app the whole planet and we found measurements that indicate there's up to maybe 200 dust devils per square mile per day during some parts of the summer and they can range from a couple of hundred feet tall to devils that stretch six or seven miles high you can get just towering monsters of dust devils that we would never see on the earth the kind of maximum size dust devils you see on mars are more like tornadoes on the earth where they're going up almost 10 kilometers so these things are just real monster systems back at arizona state university scientists blow crushed walnut shells as silicate particles in the planetary geology wind tunnel to replicate dust and wind conditions on mars if we can understand and sort of replicate what's going on then we can in a sense understand how the martian surface has been changing and continues to change as time goes on oddly enough their studies reveal that it's easier for winds to loft larger sand particles into the air than smaller dust particles this is because there's cohesional forces and static forces between the small the very small fine dust grains we imaged the rover deck and actually found that sand seemed to have bounced onto the solar panels and we can see the skip marks across the surface and this is interesting because we don't usually see sand typically reach that high dust devils on earth never have the punch to produce that kind of chaos here lucky for us but what would happen to earth if a giant martian style dust storm did overtake us if you had dust storms of martian size on the earth you would find your city being enveloped in a orange tan haze air quality plunges as the storm churns dust blots out the sun shutting down photosynthesis no plants no food temperatures would plummet 65 million years ago an asteroid may have struck the earth creating these same conditions wiping out the dinosaurs it's not going to happen on the earth though because there's going to be rainfall and moisture condensing on the dust grains and so forth and dropping them out of the atmosphere so it's very hard for something like that to spread in the climate conditions that we have on earth forecasting martian weather may someday be just as important as forecasting the weather on earth if we ever want to send a manned mission there the word environment no longer really applies just to the meadow next door and the little stream down at the end of town it's it's the whole inner solar system i mean that's really our environment now the sun's energy bathes all the planets on earth it creates hurricanes on mars planet-wide dust storms but with almost no solar energy distant neptune produces violent and powerful winds where do they come from and just how bad are they if neptune's winds were to travel to earth these alien storms would literally blow us away the orbit of neptune lies three billion miles from the sun at the outer edge of the solar system there's a lot we don't know about this big blue planet neptune's jet stream winds blast as fast as 1500 miles an hour in its upper atmosphere but how the sun controls the weather on earth and mars but it barely reaches out here no sunlight means freezing temperatures an average of minus 392 degrees fahrenheit so if there's no sun and no heat where do these incredible winds come from one of the interesting puzzles is that as you go further out in the solar system you get further from the sun the winds don't go down you still get very strong winds the energy for neptune's winds must come from somewhere and scientists are working to figure it out neptune's energy is certainly not going to be powered by solar radiation in fact the energy we detect coming out from the planet in the infrared as heat is two and a half times the energy coming in from the sun so the planet is creating its own heat not from its core which is made of rock and ice but wrapped around this icy center is a mantle of ammonia methane and water all being squeezed by enormous pressure and generating tons of heat so while neptune is frigid on the outside on the inside it's giving off a lot of heat this heat may help generate neptune's winds but they're still too strong to come from the mantle alone something else is pushing them faster and faster earth has a hot core too and it's a lot closer to the sun so why don't we have winds like neptune for one thing our oceans store and release energy and that helps generate our weather it adds energy in places takes it out in others in a very complicated system this complicated system produces a lot of wind and just where are earth's fastest winds found surprisingly not over the ocean they blow instead over the top of a fairly modestly sized mountain [Music] new hampshire's mount washington the highest winds ever observed by human beings were right here on mount washington at 231 miles an hour on april 12 in 1934 mount washington observatory a private non-profit scientific institution is responsible for tracking the weather and climate atop the 6288 foot tall mountain this remote weather station accessible only by snow tractor in the winter has kept daily records for the last 76 years it's definitely one of the most extreme locations on the planet we regularly see in the wintertime winds exceeding 100 miles per hour every few days nowhere near as ferocious as neptune yet still pretty strong but why does this mountain one-fifth the size of everest produce such fierce gusts we're at a place where we have winds converging from various directions coming from the ohio river valley coming down from the st lawrence river valley coming up the eastern seaboard all converging here in this area on top of mount washington the elevation change from the valley floor to the summit of mount washington is very significant for any mountain range it's over four thousand feet so air is forced to go over the mountain top and force to squeeze in there and it's accelerated as it squeezed over the mountain top and they measure it every hour on the hour 24 hours a day seven days a week it's blowing over 100 out here right now ice is forming on the instruments more quickly time to go up and de-ice the instruments even though it's blowing over a hundred we gotta do it every hour now ironically earth's uneven surface which channels winds into powerful gusts on mount washington ultimately knocks them down over time and this is the big difference between weather on earth and weather on neptune earth has mountains that slow winds down neptune is as smooth as a cue ball it's not so much a question of you're driving them stronger because you're not it's just that there's nothing to slow them down simply put once neptune's winds get blowing there's nothing to get in their way so what would an average neptune wind speed of 850 miles an hour due to us here on earth we have parking level winds in the earth sometimes 100 miles an hour you consider that pretty dangerous so if we sat with 900 mile an hour winds from neptune on the earth we would probably start wiping out everything on the surface and scraping everything off giant neptune takes wind and transforms it into something extreme and almost unrecognizable but orbiting just beyond the rings of saturn is a small moon that does the same thing to rain this is titan where an everyday rain shower would turn earth into an explosive fireball it's a cloudy day and a gentle rainstorm starts [Applause] here on earth you'd grab your umbrella and consider it a minor inconvenience but this isn't earth and it's no ordinary rain you're on titan a small moon of saturn and in this chemical downpour you'd need more than an umbrella to protect you the rules of earth weather definitely don't apply here but earth and titan are alike in a lot of ways on earth we have a solid surface a protective atmosphere and plenty of water all these things make life on our planet possible there's really nowhere else quite like earth anywhere in the solar system but titan comes close like earth it has a solid surface and that's not all titan has an atmosphere that's uh in general very similar to earth's in some ways it's mainly nitrogen-like earth's atmosphere it's rich with organic material also like earth's atmosphere but similar isn't the same here on earth our atmosphere has a huge supply of water in it all the time constantly evaporating and raining back down like here on the hawaiian island of kauai today we're on the slopes of mount waialeale which is the cloud shrouded mountain behind us it rains over 40 feet a year here earth's water cycle starts when warm moist ocean air rises forming clouds that eventually condense into rain the rain falls back onto the land where it eventually drains back into the ocean starting the cycle again when water evaporates it absorbs solar radiation when water condenses it releases all that energy into the atmosphere and this transfer of heat helps to moderate conditions on earth earth's water stores as much as 80 percent of the sun's heat helping keep our temperatures steady from the equator to the poles scientists theorize that titan might have water or some other liquid that might produce a similar effect and in 2004 when nasa's cassini probe visited saturn it found some pretty good evidence to support that idea if you went to titan and you were looking at the landscape you would see something that in some ways would look almost familiar to you you might see big mountains and and valleys that were carved out by by running liquids in fact as cassini flew past hazy titan its radar red the surface below scientists saw channels cutting across the surface much like rivers on earth do some as long as 900 miles the first strong evidence of liquid on titan there are large bodies of liquid on the surface of titan nowhere else in the solar system except for the earth are there any large bodies of liquid could water the liquid that carves earth's mountains and valleys also be carving these features on titan's surface or could it be something else the problem is that titan is too far away from the sun if it was water it would be frozen solid it's about minus 300 fahrenheit on titan so things behave very differently on titan than on earth because it's so cold methane which is a gas on earth is a liquid on titan one mystery solved but just because methane is a liquid on titan's surface doesn't mean it's part of a weather cycle like water on earth so how do we know that this methane also falls from titan's sky that answer is shrouded in mystery literally titan is completely covered in a thick haze of smog particles like a very very bad day on in los angeles despite the haze the cassini probe once again revealed the answer we can see the upper clouds and we can see evidence for rainfall because the clouds drop very precipitously we hypothesize that we're seeing the the effects of rainfall methane rainfall we think that titan has maintained monsoons so we think that sometimes title has a lot of rain that is able to carve rivers and leave large fluvial deposits on the surface cassini's radar imaging also revealed large methane seas on titan's surface if you have liquid methane on the surface and a lake for example that methane can evaporate off and become methane gas in the atmosphere so you have kind of a cycling of methane between liquid phase and gaseous phase and between the surface and the atmosphere that's very similar to the water cycle that occurs on the earth but methane is a flammable gas so why isn't titan on fire for any combustion you need two things you need both a fuel which methane is but you also need oxygen and on titan you lack the oxygen so the whole thing is basically a big fuel canister but there's no oxygen with which to burn it and so it's all very stable if it were cold enough here on earth to produce methane rain the oxygen in our atmosphere would create a worldwide firestorm luckily for us that can't happen titan's methane cycle makes it both alien and familiar to us to me titan is very exciting because all the materials are so different and yet this these processes produce very similar landscapes to what we see on earth titan proves that where alien weather is concerned looks can be deceiving on jupiter it's all about size drop the great red spot onto our world and it makes even our worst hurricanes look like a breeze this is the biggest and oldest storm in the solar system and jupiter's most famous feature it even has its own name the great red spot it's about two or three times the size of the earth which makes it the mother of all storms we've known about the great red spot in jupiter's southern hemisphere for more than 300 years when galileo invented the telescope within a few tens of years people were had seen the great red spot and it's still there familiar yet mysterious nobody knows how the great red spot formed but scientists are finally probing below jupiter's cloud tops to uncover more about this enormous alien storm the storm is powerful with wind speeds of 300 miles per hour it rises miles above the surrounding clouds on earth we have storms that seem similar though smaller and milder hurricanes also known as cyclones or typhoons depending on where they form they're our most destructive weather systems but is there more than just a passing resemblance between earth cyclones and jupiter's red spot when you look at the earth from space at a hurricane it's this big swirling pattern it's round it rotates jupiter's big storms look big and round and cloudy and they rotate but there the similarity ends in a hurricane there is an internal core which is called the eye of the tropical cyclone and that's a region of very calm winds and no clouds and usually has a size of about a 10 20 kilometers in diameter and then away from the eye there is the eye wall those are really cloudy regions with a lot of rain and as you move outward there is a whole region of about a couple of hundred kilometers with very very strong winds and very strong rain hurricanes draw power from heat in our oceans but jupiter has no oceans and the sun isn't close enough to power a storm as big as the great red spot so where does it get its strength part of the answer is jupiter's size it's the largest planet in the solar system almost as big as all the other planets combined [Music] this mass generates a very strong gravitational pull which in turn creates interior heat that rises to the surface another piece of the puzzle may be jupiter's hypersonic rotation despite being much larger than earth jupiter's day lasts only 10 hours in other words it spins incredibly fast could energy from this dizzying spin feed the great red spot the weather is really dominated by this fast spin there's shearing between different latitudes and that shearing plus a lot of heat that comes up from the interior of this very massive object 290 times the mass of the earth leads to very violent storms both jupiter's and earth's storms spin around in a familiar spiral shape on earth it's because of an effect called the coriolis force i'm sitting at the north pole and i want to throw a ball down to a friend who's in los angeles and so if i threw the ball in that direction the earth rotates and the ball will end up in the middle of the pacific rather than in los angeles so it's like if the trajectory was deflected to its right and that's what we call the coriolis force this force spins storms clockwise in our southern hemisphere but there is a stark difference between earth and jupiter the great red spot is in jupiter's southern hemisphere and yet it spins counterclockwise this is because of some other powerful winds it's bounded by jets which are moving in opposite directions and so like a cog between two conveyor belts they're just feeding energy and momentum into the system jupiter's complex jet streams spin the storm into organized chaos but the greatest difference between jupiter's red spot and our storms may be earth's solid surface once a hurricane hits land it comes apart pretty fast where they come over land or over mountains their behavior is very different from where they form over the oceans and over warm oceans in particular where we get hurricanes and on jupiter there's obviously no solid surface with no land mass to stop it the great red spot just keeps on spinning and spinning and spinning scientists hope to learn more about our weather by continuing to study the storm on earth there's a limit to how far ahead you can predict the weather on jupiter we can forecast where the red spot is going to be months in advance it's practical value to understand what makes weather on earth so unpredictable and [Music] aspects of the weather on jupiter are much more predictable unpredictable or not earth's weather never gets as violent as on jupiter that's lucky for us because if we shrank the great red spot down to fit on earth we'd be in for disaster on the earth we've got category five hurricanes i'll take a category 10 hurricane here not much would be left alien storms are vastly different everywhere you go in our solar system even our next door neighbor venus they say we're sister planets lucky the resemblance doesn't include weather otherwise we'd get seriously burned [Music] venus may be our nearest neighbor but somehow its weather is radically different from ours the second planet from the sun is a cross between a toxic waste dump and death valley but even worse so it's it's really it's almost a planetary definition of hell [Music] the temperature is 900 degrees fahrenheit the pressure on the surface is the same as half a mile below the earth's ocean and if that's not enough the upper atmosphere of venus is choked with sulfuric acid clouds and winds clocked at 250 miles an hour to get a comparison from venus the best thing to do is climb inside of your oven and crank it up and then in terms of pressure you're talking about deep sea diving it's like nothing there's nothing comparable on the earth it's just a very very extreme object on venus there's just no escaping the heat if you built up a hot spot on venus the massive atmosphere would just carry that heat away and spread it around but venus shines so brightly in the night sky because its thick clouds reflect almost all the sunlight it receives in fact some early scientists assumed venus would have moderate earth-like temperatures when we went by venus in 1962 with a spacecraft we thought we would find a surface at 90 degrees fahrenheit sort of like miami florida we were dead wrong something else must be at work on venus but what so why doesn't venus cool off the same way earth does on the earth for example we have sunlight coming in hitting the surface of the earth earth warms up a little bit but the oxygen and the nitrogen in the atmosphere don't impede the light so when it gets released out in the infrared it goes right through the atmosphere and leaves and goes into space but on venus the atmosphere is 97 carbon dioxide giving a whole new meaning to the greenhouse effect it becomes very very hard for the surface to get its energy out so venus really taught us a lesson that if you have a blanketing gas a greenhouse gas you can warm up the atmosphere tremendously but why does venus have so much more co2 in its atmosphere than earth the two have much in common they're even called sister planets they're almost the same size have roughly the same amount of carbon and billions of years ago both had lots of water but eons ago their paths mysteriously diverged on earth water fostered life the earth has most of its carbon in life forms in the trees and the animals but if you took all that carbon that's in the near surface rocks and burned it up or released it you would then create an atmosphere very much like venus venus's close proximity to the sun made it too hot to sustain liquid water instead its water evaporated into the atmosphere trapping the heat deposited by the sun and creating a runaway greenhouse effect once in the atmosphere the water molecules were exposed to solar ultraviolet rays that broke the molecules apart well he wasn't recognized by the scientific community how important the greenhouse effect was prior to going by venus and seeing this amazing place where it was 900 degrees fahrenheit not 90. it took several doomed missions to venus to figure it out starting in the 1960s both the united states and the soviet union sent unmanned probes past the planet and down to its surface it didn't take long before venus crushed and burned them then in 1981 the soviet lander venera 13 set a record for survival on the surface of venus two hours and seven minutes it was able to take pictures and samples of the surface before being overcome by the heat you're sitting there with us 900 degrees fahrenheit heat all around you it's going to get in there and bake you after a while scientists one day hope to send a probe to venus that can survive its hellish environment to help us confirm our theory of how this planet went astray because if circumstances were just a little different our sister planet might just be our twin remove our atmospheric shield and you're on the road to hell as soon as you're heated up uh to something like 400 degrees or so you probably start getting some smoldering smoke and way before it gets to 900 degrees the earth would burst into planes because all the oxygen around once the oceans boiled away the carbon locked in rocks on the ocean floor would cook and over millions of years re-enter the atmosphere probably if you came back to the earth system after this happened you'd find a planet looking much like venus we're a long ways away from such a drastic change but it's sobering to look at earth's sister planet when the sister planet went on a very different track than we did so cosmic forces turned venus into a planetary barbecue but on this violent stormy world time and the elements have produced some of the strongest thunderstorms ever measured welcome to saturn [Music] lightning cuts the sky this violent weather system grows bigger than the entire united states as it pummels the atmosphere with the most powerful lightning ever seen except this lightning can't be seen because these bolts are electrifying the skies over saturn despite the raw power of saturn's lightning scientists have been unable to see it partly because saturn's rings are too bright the rings are so bright if you were on the night side of saturn it would be considerably brighter than the earth under a full moon but saturn also hides its lightning within thick choking clouds of ammonia it's probably 100 kilometers down that the lightning is happening and that complicates uh seeing the lightning flashes but the lightning is there and scientists know it because they've heard it radio wave detectors on the cassini orbiter have recorded the sound of saturn's lightning we can hear the static of lightning just as you could with an am radio uh going down the highway on earth and this static reveals the power of the lightning that we can't see you can measure the energy in those radio waves and compare it with the energy that your radio picks up when there's a thunderstorm around on earth and the saturn ones are big they're more powerful maybe a hundred times and earth's lightning can help scientists understand how storms work on saturn within earth's storm clouds just like in saturn's updrafts drive moisture higher causing ice to form these ice crystals rub against each other take on a positive charge and become attracted to negatively charged water droplets lower in the cloud this sets the stage for a potentially powerful discharge of energy once you get that charge separation that builds up so intensely that some theorize that it can be as strong as 100 million volts that the cloud then must release that energy on saturn the same thing happens on a much larger scale in fact the lightning is a hundred times stronger than earth's that's a staggering 10 billion volts of electricity thunderstorms in saturn's southern hemisphere span thousands of miles and can last as long as a month but scientists aren't sure what makes saturn's storms bigger and longer lasting it could be saturn's super saturated atmosphere probably the fact that there's more water in the atmosphere pound for pound on saturn is is makes the storms bigger more water droplets means more friction which means bigger lightning bolts but energy emerging from the planet may also contribute to the power in saturn's thunderstorms it turns out that where lightning alley is on saturn is a place where the winds are flowing the slowest if you go deep down in the atmosphere you'll see the same winds as you do up high it's a place where the energy being released deep down below can make it on up to the upper atmosphere without being sheared apart and allows storm systems to be organized earth's atmosphere isn't built that way so as violent as our storms get they're nothing compared to the systems on saturn even a run-of-the-mill mega thunderstorm on saturn would devastate us here a saturn-sized thunderstorm on the earth would mean a thunderstorm that grows to cover all of north america and presumably has very strong winds and rain this is something that's unprecedented on the earth saturn's hyper violent thunderstorms are proof that our planetary neighbors have weather far more ferocious than ours but the laws of physics that create saturn storms are the same laws that create our own weather massive dust storms unrelenting winds killer lightning powerful hurricanes and searing heat the year is 2154. our planet has been ruined by environmental catastrophe [Music] in the movie avatar greedy prospectors from earth descend on the world of an ancient hunter-gatherer people named the navi their home is a lush moon far beyond our solar system named pandora [Music] could such a place exist [Music] and could our technology and our appetite for exploration one day send us hurtling out to reach it in fact the supposed site of this fictional solar system is one of our most likely real interstellar targets until a better destination turns up [Music] pandora orbits a fictional gas planet called polyphemus its home is a real place alpha centauri the brightest star in the southern constellation of centaurus at 4.37 light years away it's part of the closest star system to our sun alpha centauri is actually two stars a and b one slightly larger and more luminous than our own sun the other slightly smaller [Music] the two stars orbit one another swinging in as close as saturn is to our sun then back out to the distance of pluto this means that any outer planets in this system anything beyond say the orbit of mars would likely have been pulled away by the companion and flung out into space for this reason alpha centauri was not high on planet hunters lists until they began studying a star 45 light years away called gamma cepheii it has a small companion star that goes around it every 76 years now it seems it also has at least one planet [Music] that world is about the size of jupiter and it has planet hunters excited perhaps two-thirds of all the stars in our galaxy are in so-called binary relationships that means there could be many more planets in our galaxy than astronomers once assumed at least three teams are now conducting long-term studies of alpha centauri searching for slight wobbles in the light of each companion star that could indicate the presence of planets if they find a planet that passes in front of one of the stars astronomers will begin intensive studies to find out what it's like one of their most promising tools will be the james webb space telescope scheduled for launch in 2014 or 2015 from a position a million miles away from earth it will deploy a sun shield the size of a tennis court and a mirror over 21 feet wide [Music] the largest space telescope ever built it will offer an extraordinary new window into potential solar systems like alpha centauri with its infrared light detectors this telescope will be able to discern the chemical composition of a planet's atmosphere and perhaps whether it harbors a moon like pandora one prominent planet hunter predicted that if a habitable world is found at alpha centauri the planning for a space mission would begin immediately [Music] here's that star duo seen by the cassini spacecraft just above the rings of saturn to actually get to this pair of stars you'd have to travel as far as the orbit of saturn then go another thirty thousand times further or put another way if the distance to alpha centauri is the equivalent of new york to chicago then saturn would be just one meter away so far the immense distances have not stopped us from launching missions into deep space in 1977 the twin voyager spacecraft were each sent on their way aboard titan three centaur rockets after a series of gravitational assists from the giant outer planets the spacecraft are now flying out of the solar system at about 40 000 miles per hour they're moving so quickly that they could each whip around earth in just 45 minutes twice as fast as the international space station voyager 1 has now traveled over 110 astronomical units that's 110 times the average distance between earth and sun or about 10 billion miles but don't hold your breath if it was headed in the right direction it would need another 73 000 years to travel the 273 000 astronomical units to alpha centauri when it comes to space travel we've yet to realize the dream forged by rocketeers a century ago a russian school teacher konstantin zielkowski inspired generations of space visionaries with sophisticated ideas about multi-stage launch vehicles he imagined the construction of space stations in earth orbit and eventually vast permanent space colonies in time he predicted we'd evolve into a whole new species homo cosmicos [Music] [Music] since then rocketry's greatest advances have centered on ways of containing explosive propellants and methods of maintaining stable flight at high speeds [Music] the problem is that chemical rockets are just not efficient for long distance space travel to reach the speed needed to enter orbit around earth 500 miles per hour the space shuttle must carry 15 times its weight in fuel and that's efficient compared to some other rocket systems and you'd need to be traveling more than 25 000 miles per hour to break free of earth's orbit and go anywhere else a nasa study showed that to send a space shuttle sized craft to alpha centauri in 900 years would take an unbelievable amount of fuel 10 to the 137th kilograms of rocket propellant suffice to say it's more mass than is in the entire visible universe while only a very tiny percentage of nasa's budget goes to advanced propulsion there are some promising ideas on the drawing board rockets powered by nuclear fuel or plasma a super volatile gas huge sails pushed along by the pressure of photons from the sun ion drives but to reach alpha centauri within a human time scale we'll have to go with the most potent fuel in nature that we currently know it's the science fiction fuel of choice antimatter [Music] in james cameron's avatar hybrid nuclear fusion and antimatter engines power a mile-long interstellar spaceship at a speed of 670 million miles per hour this vehicle makes the journey to alpha centauri in just six years antimatter really does exist as the mirror image of the universe we know it consists of electrons and protons but with their electrical charges reversed whenever it comes into contact with normal matter the two annihilate each other in a ferocious blast of energy [Music] large amounts of antimatter were created and destroyed in the fiery dawn of our universe the big bang but somehow in one of the great mysteries in science we were left with a universe whose visible substance is almost all normal matter [Music] the universe still produces antimatter through powerful collisions such as a jet from a black hole slamming into a cloud of gas when mata and antimatter obliterate one another they emit gamma radiation that we can then detect with instruments such as the fermi gamma ray space telescope [Music] fortunately black holes aren't the only way to generate antimatter in giant labs like the large hadron collider scientists accelerate atoms to nearly the speed of light and blast them together to expose their fundamental constituents small amounts of antimatter can be made this way but it's incredibly expensive with a dedicated facility the cost of producing it might come down far enough to produce usable amounts and that's the hope of one researcher dr gerald smith has been working for over a decade to find a way to trap this volatile substance and store it in isolation from the rest of the universe smith and his colleagues have designed a trap the size of a cigar case it sits within a tank filled with liquid nitrogen and liquid helium designed to cool it down to 270 degrees below zero once injected into this trap antimatter particles are suspended by magnetic fields within a vacuum as empty as deepest space but the problem is that anti-electrons called positrons tend to repel each other explosively that makes it tough to store more than a few at a time this team now believes it may have discovered a pathway to storing large amounts over longer periods of time their solution lies in combining positrons with electrons forming an element called positronium in theory with the right magnetic fields these electrically neutral atoms might be held indefinitely when released under controlled conditions ultra high energy anti-matter beams could turn out to be ideal cancer killers or lead to revolutionary industrial applications or perhaps one day they could power long-distance spaceflight [Music] it wouldn't take much antimatter is so potent that it defies common sense a chunk the size of a small coin could propel the space shuttle into orbit smith estimates that once in low earth orbit a human mission to mars would take as little as 10 milligrams worth the basic idea of an anti-matter rocket is simple a beam of positrons is released into the engine core where it annihilates the surface of a metal plate that creates an explosion that propels the craft forward another design uses a sail a cloud of antimatter particles reacts explosively to its surface propelling it forward short of traveling to another solar system there may be good reasons to contemplate developing antimatter propulsion a preliminary mission would speed beyond the orbit of pluto sending back close-up images of dark planet-like objects that ring the solar system out in the kuiper belt [Music] a longer distance probe could reveal new details about the oort cloud a vast realm of comets that envelops the solar system once out there it could sample particles that make up the interstellar medium or send back unique data sets on dark matter the invisible stuff that makes up the overwhelming portion of our universe to make it all the way to alphas and dowry within 50 years an antimatter probe would have to gradually accelerate to around 10 percent the speed of light at 67 million miles per hour it would then gradually decelerate as it approached its destination at those speeds hitting even a grain of dust could destroy the spacecraft so it might be best to slow the journey down to a century or more it's safe to assume for now that we would only send a probe to alpha centauri if we discovered a habitable world there may be other choices in our solar neighborhood they include proxima centauri a red dwarf star 4.2 light years away that may be gravitationally bound to alpha centauri beyond that not quite six light years away is barnard's star [Music] or there's leland 21 185 a red dwarf 8.3 light years away we already know it has two jupiter-sized planets there are at least 22 stars within 12 light years of earth and any way you look at it the first interstellar voyage will be a quantum leap for humanity the urge to reach out to distant horizons to climb the highest peaks to push ourselves past our perceived limits seems to be a vital part of what makes us human yet explorers of old set off not just because it was there at times it was greed hunger fear or despair that propelled them outward from their homelands and allowed them to endure their long journeys whether we attempt to make this leap to the stars may come to depend on how we regard this planet to the physicist stephen hawking the journey is imperative i don't think the human race he said will survive the next thousand years unless we spread into space there are too many accidents that can befall life on a single planet indeed we can't foresee the impact of wars social upheaval or the course of human civilization in coming centuries [Music] but today we can see the often conflicting trends that could one day propel us out into the interstellar void on one hand the technological advances that might make such a mission possible could revolutionize many other aspects of life on this planet the ever-increasing rate at which numbers of transistors can be placed inexpensively on computer microchips has become a metaphor for the advance of all technologies in this century from a few thousand transistors on the first printed circuits of the 1970s computer chips now have billions etched onto their surfaces even that number could seem amazingly small in another few decades many observers forecast a steep rise even an acceleration in the pace of invention and basic research and for whole new solutions to the problems of energy food production health and more on the other hand major periods of scarcity may loom in the 20th century the world saw the largest increase in its human population from less than 2 billion up to 6 billion the world's population is now around 6.8 billion it's expected to reach 9 to 10 billion by the year 2040 with the biggest gains in asia and africa [Music] according to a recent u n report the world will have to produce 70 more food by the year 2050 and at least that much more energy to sustain its population the scarcity of just simple clean water in some regions is already frightening now throw in environmental impacts like rising sea levels or the spread of deserts linked to a gradually warming climate the culprit to most scientists is rising emission of greenhouse gases like carbon dioxide since the start of the industrial revolution this map charts rising temperature readings from the year 1885 through to the present in some places they've gone up by as much as two and a half degrees fahrenheit computer models project the trend out to the end of this century depending upon population growth energy use and conservation temperatures could rise anywhere from 2 to 11 degrees more will technological advancements allow us to halt the degradation of our natural environments and increase the carrying capacity of our planet [Music] will we find ways to mitigate the impacts of war natural catastrophes or political upheavals no doubt if or when we launch our first mission beyond this solar system the occasion will spur reflection on who and what we have become as a people as a planet just as the first missions to the moon and our neighboring planets once did at first we'll send a probe designed to relay basic information on what's there on a world whose light we have only studied from afar as this cosmic emissary makes its way across the void we on earth will continue to struggle in our pursuits of happiness and prosperity or of mere survival when it arrives we'll scan the data for evidence of a world like our own one that may harbor life [Music] how will our perspectives on that world and upon our own have changed [Music] so [Music] we think of comets as some of the heavens more spectacular pieces of eye candy and most are benign orbiting harmlessly around the sun but some will inevitably collide with another body like earth at speeds of 25 000 miles an hour even a small cosmic raider can wreak enormous havoc but a larger object over a mile or more in diameter could cause devastation on a global scale an impact by a comet will kill so many people and can produce such long-term changes in the environment that it can be a complete catastrophe for all of humanity scientists now believe a single blast from space helped wipe out the dinosaurs 65 million years ago a comet or asteroid about six miles across slammed into mexico's yucatan peninsula it dug a crater nearly 50 miles wide and 20 miles deep in less than a second and unleashed an explosion more powerful than all the world's nuclear weapons combined the force of the shock waves triggered earthquakes worldwide and sent tsunamis surging across the oceans a mammoth dirt cloud erupted miles into the sky engulfing the globe and blocking out the sun for years [Music] the dinosaurs slowly perished and they were not alone more than half of the earth's species were also wiped out in our solar system there are two kinds of cosmic bullets capable of devastation on a planetary scale asteroids and comets asteroids are essentially tiny planets dense boulders of rock and metal left over from the formation of our solar system 4.6 billion years ago [Music] most are bunched between mars and jupiter in an orbit called the asteroid belt comets on the other hand are far more mysterious though also formed at the birth of our solar system they are made up of rock and ice many like hayley's comet orbit the sun in predictable paths on predictable schedules [Music] but there are countless others we know nothing about they come hurtling out of the ether at unimaginable speeds of up to 100 000 miles per hour [Music] for scientists peering into space they look like lumps of charcoal on a black canvas invisible until they are practically upon us only near the sun do comets become easier to detect these icy bodies shed gas and dust as the sun warms them when light hits the debris they blaze into view and can be seen for millions of miles but by that time if one is headed for us it may be too late to do anything to stop it to date more than one thousand comets have been identified every year we spot perhaps a hundred comets we've never seen before entering the inner solar system each new arrival increases the odds that one will eventually strike the earth [Music] the earth is in a cosmic shooting gallery we get hit by pieces of comets and asteroids of all size and the big ones certainly pose a very real threat it's only a matter of time before the comet is in the same place as the earth giant pock marks all over our planet testify to past assaults and these collisions may be more frequent than we like to think the latest big one happened a little more than a century ago in 1908 a massive explosion rocked tunguska in russia's remote region of siberia eyewitnesses described a flying star with a fiery tale the sky opened and a fire brighter than the sun poured out whether an asteroid or a comet it collided with the earth's dense atmosphere at such a high rate of speed the friction caused it to explode in mid air it blew up five miles above the surface of the earth creating this huge explosion and lit up the atmosphere for days you could actually read in europe at night the tunguska blast as we now call it was bigger and more powerful than the eruption of mount st helens it left no telltale crater but it did flatten a forest of millions of trees over hundreds of square miles an area bigger than that of washington dc if that would have happened over a metropolitan area it would have just wiped out the population for thousands of square kilometers around the impact site to astronomers tunguska was a near mess a relatively minor impact but a major impact from a comet would have devastating effects imagine the following scenario scientists have spotted a two mile wide comet on a collision course with earth it's too late to stop it the first thing you'll know is when the sky lights up and the ground shakes brilliant meteors streak across the sky as the giant comet's debris strikes the earth's atmosphere forests catch fire ignited by the superheated air when the comet hits the blast kicks up millions of tons of fiery rock and dirt the airborne debris blankets the planet and blocks out the sun [Music] day turns to permanent night bringing freezing temperatures and year round winter it takes more than a year for the dust to settle and sunlight to filter through the clouds when it does the earth starts to warm quickly elevated levels of gases created by the fires turn the planet into a sweltering greenhouse millions of species of living things that survive the earlier cold cannot take the heat they die it takes thousands of years for life on earth to recover how great are the odds a comet will strike the earth will another impact occur you bet it's going to happen again the earth is sitting out there with a bullseye on it the chances of a major impact in our lifetimes may be slim perhaps on the order of one and one hundred thousand but astronomers the world over are working fervently to understand these strangers in our midst struggling to learn what comets are and where they come from mankind's ultimate survival may depend on our ability to stop one before it strikes donald yeomans studied comets for nasa's jet propulsion laboratory they're so big that they've got a lot of mass and it's mass and velocity that's important when they hit [Music] if we could track comets in advance and plot their orbits we'd likely have many years of warning if the orbits veer toward us [Music] it may seem like a tall order to scan the vast sea of space for that one pinprick that could spell disaster but that's exactly what astronomers are doing in 1992 the us government launched an aggressive program to analyze the threat comets and asteroids pose to earth it's called the space guard survey today scientists all over the world are involved in the painstaking process they point their telescopes at a single region of the sky and take periodic snapshots then they line up the images looking for anything that moves from frame to frame we are looking first for the larger asteroids and commas the ones mile or so in diameter and eventually we'll extend it to the smaller ones scientists have discovered nearly 4 000 comets in our solar system with roughly 40 new ones in 2016 new comets are being discovered every year we may never be able to locate every threat there could be millions of comets and asteroids that measure 300 feet or so the length of a sports field [Music] still telescopes are a first line of defense against what could be a major disaster for our planet if you don't look you won't know anything's coming we would be taken by surprise just as much as the dinosaurs if you do carry out a survey then you hope that you can have warning but it's one or the other either you have years or decades of warning or you're taken completely by surprise there's nothing in between there's three things that are important you have to find them early you have to find them early and you have to find them early [Music] suppose we do detect a comet headed for earth then what can we do scientists have just started to come up with solutions one of the leading ideas smash a rocket into it to slow it or knock it off course that's harder than it may seem in 2005 scientists were ready to test their theories about how a comet would react when it was hit by crashing a rocket into one it was called deep impact it began here at nasa's vertical gun range in mountain view california where it was the job of dr pete schultz and his team to figure out what the comet would do when it was hit [Music] this particular instrument allows us to fire a small sphere about a quarter inch at speeds that are maybe six or seven times the speed of a rifle bullet this whole assembly rotates up to an elevation where the gun is basically three stories high this allows us to send the projectile through different openings in the chamber so that we can impact a flat surface at different angles scientists believe comments vary in their makeup so schultz and his team built several different models then hit each with a shot from their ultra high speed gun the first scenario is what happens if we impact into something looks like lunar dust the second one is what happens if we impact into fluff and the third one is what happens if we impact into a fluff covered with an organic layer as we go down and look at the evolution of this crater we find at the very end after it's finished we can still see the crater here but in these two cases when we're using fluff we can't see the crater it's completely masked the fluff completely absorbed the projectile a frustrating result for scientists hoping to get a look inside and there was another possibility schultz had to consider what if the entire comet is extremely fragile and porous he searched for a substance for that simulation the comet may be sort of like a fluff ball it may have been very low density what do we do to try to simulate that the best thing probably is a complex organic what would that be cotton candy we've got our comet made of cotton candy let's turn off the lights and let's get out of here the projectile soars right through the comet but the force shatters it [Music] oh my god there's no more comment that's for sure what a mess but this is not good news a shattered comet can be even more dangerous than an intact one the pieces remain on the same course turning one projectile into many but what does that mean for our planet if we're in the way in 2005 the team at nasa had completed their tests and were ready to take the plunge they would try to drive an 820 pound impactor into a comet to find out what's inside deep impact principal investigator dr michael lahern so here we have the uh model of both deep impact spacecraft many people think it was only one spacecraft but it's really two january 12 2005 after six years of study and preparation deep impact is ready for liftoff three two one we have ignition and liftoff of a delta ii rocket carrying deep impact the spacecraft's destination is a four mile wide comet named temple one discovered in 1867 it's well known to astronomers it orbits the sun every five and a half years and has lost much of its gas and ice people would argue that you should preserve the comets for posterity but doing a violent study on one that is just typical of a whole class seemed to us to be the right choice for science deep impact takes five months to reach temple one's orbit [Music] on july 2nd 2005 it turns and points its cameras at the comet 500 000 miles away then it releases its impactor if all goes well the collision will blow a hole in temple one about 600 feet across five stories deep about the size of the roman coliseum but it might destroy the comet by breaking it apart like cotton candy in the experiment [Music] back on earth hundreds of scientists hold their breath we lost signal and we had to stand there and wait around so everybody was trying to be you know go keep busy and not feel anxious but just before impact the signal returns [Music] the half mile wide comet and nasa's 820 pound craft have collided at 23 000 miles an hour the explosion is equal to nearly five tons of tnt it completely vaporizes the impactor and kicks up far more dust than anyone expects the amount of dust is a telltale clue to the comet's makeup temple 1 at least on the surface contains far less ice than scientists expected this is the first data we've ever had so in that sense it's revolutionary analysis of the dust showed molecules containing carbon organic material so it's plausible that comets could have brought such material to earth early in its history scientists hope to learn something else from deep impact clues about how to stop a comet from colliding with earth some thought deep impact might knock temple one into a slightly different orbit but the comet has continued on exactly the same path as before it was a secondary objective of the deep impact mission to come up with a plan to mitigate an impact if we had to did we figure out what it would take to move a comet out of an orbit that was intersecting the earth we didn't figure out enough one plan calls for detonating a nuclear warhead near the comet to nudge it onto a different path a controversial proposal because of the unknown consequences of releasing radiation in space others have called for drilling into the nucleus and setting off a blast inside but as we've seen this has the danger of turning one deadly projectile into many the pieces could continue on the same orbit and like the blast from a shotgun wreak destruction over a wider area some have proposed less violent yet equally intriguing solutions they suggest putting lasers on the moon where the earth's atmosphere would not deflect them the lasers could bore into a comet and melt its icy glue we might even hitch a spacecraft to a comet and tow it out of our way whatever the solution all ideas remain on the drawing board if a comet is on a collision course we may not be able to do anything [Music] [Music] [Music] so [Music] at the dawn of the 21st century space agencies in europe and america began making plans to land the first humans on mars but manned missions to the red planet have been proposed before [Music] for some mars holds the answers to mankind's future in space others say mars is too far too dangerous and too expensive for humans to explore and in a world torn by troubles some say there is no need or will for mankind to reach into space anymore more than 30 years after the last apollo astronaut walked on the moon the american manned space program seems to have lost its way unable to reach beyond even low earth orbit [Music] we've got a problem nasa has been literally going around in circles with its space program for the past 30 years astronautical engineer dr robert zubrin has been arguing for years that sending humans to mars is the mission the space program needs it's time that we set goals for nasa that we're worthy of the risks of human spaceflight mars is the next logical step in our space program it's the challenge that's been staring us in the face for the past 30 years it's the planet that's most likely earth it's the planet that has on it the resources needed to support life and therefore someday technological civilization it's the planet that will provide us with the answer as to whether life is prevalent in the universe or exclusive to the earth and it's the planet that will give us the critical tests to where the humanity can break out of the planet of our birth and become a space faring species in the early 1990s zubrin was the head of the mars direct program at martin marietta astronautics his team developed a mission to mars that could be done at a fraction of nasa's projected costs using only existing technology zubrin argues that the first steps on martian soil could be made within 10 years there is absolutely nothing in this that is beyond our technology we are not ready to send humans to mars right now we don't know how to keep them alive there are people out there who say we can go to mars tomorrow uh one of my requirements one of nasa's requirements is that if we send humans to mars we bring them back alive for the past 15 years zubrin and his colleagues have waged a campaign to convince society and the political class that humans on mars should be the goal for nasa now this is the story of our cold neighboring planet and the debate over where the man's fate is tied to the red world it's the story of an engineer's journey and the battle of ideas over which direction in space will truly benefit mankind we're at a crossroads today we either muster the courage to go or we risk the possibility of stagnation in the key the victor in this debate could determine the fate of mankind will we become a space faring species will we live on more than one planet [Music] in the winter of 2003 the chinese put their first taikonaut in space [Music] the chinese space administration plans to begin a manned programme of moon exploration by 2017 the european space agency has outlined a plan for humans to the moon by 2024 and to mars by 2033 [Music] and the russians building on years of experience are conducting tests for long-duration mars missions in america with the impending retirement of the shuttle fleet and the completion of the international space station the bush administration announced in 2004 the constellation program on the moon a plan that would return americans to the moon by 2020 but the program was never fully funded and was eventually cancelled in 2010 the obama administration announced its vision for nasa and human mars exploration by the mid-2030s i believe we can send humans to orbit mars and return them safely to earth and a landing on mars will follow and i expect to be around to see it with a new timeline for humans to mars sometime after 2035 and with administrations changing every four or eight years it is far from certain that such a plan will be realized twenty years earlier the first president bush also proposed a long-term human exploration program under great fanfare the program quietly died in congress a few years later if you want to go to mars you cannot do it in 30 years you can't do in 20s you got to do it in 10 years or less from program start or you're more or less guaranteeing political failure to date only the apollo moon program which was announced in 1961 and had men on the moon eight years later has succeeded in getting astronauts beyond low earth orbit [Music] i was five when sputnik flew and while to the adults sputnik was a terrifying event to me as a child who was already reading science fiction it was exhilarating because it meant that this possibility of a space-fearing future was going to be real and i was nine when kennedy gave his speech committing us to the moon in this decade and do the other things not because they are easy but because they are hard i grew up during the 60s when it was mercury was gemini apollo every month nasa was doing something more impressive than in the month before we were going to be on the moon by 1970 mars by 1980 saturn by 1990 alpha centauri by the year 2000 we were moving out and i wanted to be part of that and so i got myself a scientific education but then in the early 70s it's all collapsed we achieved the first part of that program moon by 1970 but the nixon administration shut down the rest and we did not move out into space and for a while i accepted that grudgingly became a science teacher but then in the early 80s something hit me and i said i'm not going to accept myself doing less than what i dreamed of doing when i was a boy zubrin went back to graduate school getting advanced degrees in engineering and aerospace he then went on to work at martin marietta which later became lockheed martin designing interplanetary missions it was here that zubrin's obsession with the red planet began to take hold [Music] while at martin in the 1990s zubrin and his colleagues developed a plan for sending humans to mars that changed nasa's thinking on the issue but the plan has languished on the drawing boards ever since now as president of the mars society zubrin is at center stage in the debate over the future of manned space flight [Music] known as a smart visionary scientist he has authored several books on exploring space and is the self-appointed spokesman for the possibility of colonizing mars mars is where the future is mars is the closest planet to the earth that has honored all the resources needed to support life and therefore technological civilization it has water it has carbon it has nitrogens it has a 24-hour day it has a complex geological history that has created mineral ore it has sources of geothermal energy mars is a place we can settle one reason for such optimism over a frozen world like mars is evidence that two billion years ago mars was a much warmer and wetter place we think that at one time in the ancient past mars was very similar to the condition of early earth this martian warm age lasted for over a billion years and could have been a suitable environment for the development of life if we go to mars and find evidence of a second genesis on mars i think we can conclude that the universe is full of life we can probably conclude that on some planets that life evolves to more complex forms and i think we'd be reasonable to conclude that intelligence could also emerge on some planets as well it really does answer the question are we alone that to me is a question that transcends science it's a philosophical societal as well as scientific question to me that's the big prize that's what why mars is interesting that's why human exploration makes sense space programs are often criticized for the huge sums of money they require although the american space program is less than one percent of the federal budget a human mission to mars may have to wait for better times there are those who say that we have many problems to deal with here on earth and we need to postpone ventures such as the human exploration on mars until these problems are solved well there were many problems in spain in 1492 and there still are there are problems that need to be dealt with here on earth and should be dealt with but we also have to think of the future we also have to think about opening up new volumes in human history [Music] i believe that it's essential for a positive human future that humanity expand into space [Music] the greatest value that we got out of apollo was the creation of intellectual capital through the inspiring of millions to go into science and engineering to be part of the great adventure of human expansion into space there's a phrase that happened with the apollo program which was if we can go to the moon we can and everybody's filled in whatever they were interested in build mass transit cure cancer do this do that the point is it did give us a sense that we could accomplish great things it did bring out the best of us we excited a generation of engineers and scientists the generation that built the computers and cell phones and all the technology everybody uses today and takes for granted if we set humans to mars as our goal we'll get millions of new scientists that will create new inventions new industries this is the enormous payback and we can get it if we set the kind of challenge that will inspire the youth to zubrin civilizations like people thrive on challenge and decay without it we have everything we have today because of our predecessors who had the courage to leave the world of the known and go out into the wilderness and build new cities and if we stop being people like that then we will hand down much less to our posterity than our ancestors handed down to us so there's the choice in life one either grows or one decays grow or die i think we should grow history proves that we have never lost by pressing the limits of our frontier in the summer of 1989 the first president bush announced the space exploration initiative directing nasa to draw up long-term plans to get humans back to the moon and begin developing a program of manned mars exploration at martin marietta zubrin and his colleagues looked forward to moving nasa's space programme outwards after two decades in low earth orbit of course we were very excited when bush made his call saying that he was making a national commitment to implement such a program nasa assembled a large team to take on the space initiative in 90 days the team developed a 30-year plan that required an enormous build-up of space infrastructure what the nasa bureaucracy decided to do was basically design the most complex mission they possibly could in order to make sure that everyone's pet technology would remain mission critical which is the exact opposite of the correct way to do engineering first nasa would triple the size of the planned space station and add enormous hangars as well as free-floating fuel depots checkout docks and cruise stations then on the moon they would construct more ship building facilities bases and depots next the moon crew would construct the mars ship a huge craft dubbed by its detractors as battle star galactica this ship would carry everything to mars over an 18-month flight once in mars orbit a small group would descend to the surface spend a few days then plant a flag in the ground and go home the plan became known as the 90-day report to those of us at martin who had been engaged in designing mars missions when they saw the monstrosity of complexity of the 90 day report we were dismayed and it was readily apparent to anyone with any insight that that program would fail politically the plan was submitted to congress the estimated cost 450 billion the legislators went into sticker shock this would have been the single most expensive program for the united states since world war ii by the end of 1990 congress had refused all requests for sei funding when the realization came the sei was doomed zubrin wrote a memo to his colleagues martin marietta outlining his problems with the nasa plan and arguing for a more direct approach zubrin favored launching a mars mission directly from the surface of earth using only existing rocket technology this negated the need for a lunar base and avoided the complexity and cost of building ships in space he also objected to nasa's plan for a short surface stay on mars a mission that would amount to little more than a flag and footprints exercise to zubrin we were going to mars to explore and develop a new world to maximize surface time zubrin proposed using a faster flight path known as a conjunction-class mission [Music] this would mean a crew could arrive on mars after only a six month journey they would then remain on the martian surface for a year and a half this would give the team time to explore a wide area and conduct detailed research about the planet then as the earth return window opens the crew would launch from mars to the six-month trip home zubrin was convinced that a simplified more robust and cost-effective mission could be designed using these principles along with several like-minded colleagues zubrin decided to ask management at martin to allow them to design alternative mars missions the management approved and we formed a team was known as the scenario development team of just 12 people from the whole very large martin company one team member whose thinking was closely aligned with zubrin's was david baker i went off to my office and said all right how would i do a mars mission if i had to pay for it and i had to go on the ride and i said well it's going to be simple it's going to be no on orbit assembly i really tried to take everything out of the mission that didn't absolutely need to be there while the rest of the team focused on longer term more traditional mission plans the required on-orbit assembly zubrin and baker decided to collaborate on a mission that could be done near term we decided to do mars the way lewis and clark did america okay use local resources travel light live off the land zurban and baker were convinced that a mars mission could be launched directly from the ground the other team members felt this was impossible that the weight of the rocket fuel required for a round trip to mars was so enormous it would render the launch ship impossibly heavy to solve this problem zubrin was exploring a radical idea that had been kicked around the aerospace industry since the 1970s the idea was to produce a methane oxygen rocket fuel directly from the martian atmosphere it was a relatively simple and robust chemical engineering procedure that was done commonly in the 1800s the era of the gaslight if the idea worked astronauts could land a relatively light ship with empty tanks they wouldn't have to ship all the fuel with them for their return trip this would radically lower their size and weight the only problem was methane oxygen fuel requires a hydrogen component hydrogen exists on mars in the form of h2o but water may be difficult or impossible to extract from the martian environment really the hydrogen was only five percent of the total weight of the methane oxygen propellant being manufactured so if you just say okay we won't be pure we won't get all of the propellant from morris we'll just get 95 percent of the propellant for mars the other five percent of the hydrogen will just bring from earth another fundamental resource that could be extracted from the martian environment is oxygen a second processing unit could separate oxygen molecules from the thin carbon dioxide atmosphere providing breathable air for a mars crew if used intelligently the same resources that make mars interesting are precisely what could make it attainable baker and zubrin had greatly reduced their mission mass but they still found their ship was too heavy and would require two launches and assembly in space then zubrin hit on an idea one of the key events of the mars direct development was one morning bob burst in my office and said i've got it the idea that i finally hit on in 1989 was that we would split the mission up into two parts and we'd send the return vehicle out first with its own return propellant plant so the propellant would be made on mars before the first astronauts ever left her with two separate direct-to-mars launches a human crew would have a fully fueled ship waiting for them on the surface of mars before they ever left earth so zubrin and baker had come up with a plan that seemed to accomplish all of their goals it was relatively inexpensive development time was short they could use existing technology and it allowed for a long stay on the martian surface they dubbed their idea mars direct no one is aboard this ship it will pave the way for the astronauts who years later will use the erv to return to earth so [Music] on its second day the erv deploys a small nuclear power reactor the reactor powers a chemical plant inside the erv the plant will produce the methane oxygen rocket fuel for the launch home [Music] nearby a second robotic rover is guided to a pre-picked landing site for the human crew it places a radar transponder to help guide the astronauts in the long journey to land a human being on mars begins [Music] carrying the most skillfully assembled flight team in history four astronauts begin their two and a half year mission to the red planet this will be the first time a human has gone beyond the earth moon system 250 million miles farther than any person has ever been to counter the health problems of zero gravity and to fully acclimate the astronauts to mars the ship will deploy a weighted tether attached to the last stage of the spent rocket booster by thrusting the ship into a rotational spin the counterweight of the rocket will create centrifugal force and thus artificial gravity the crew will be able to live with their feet planted firmly on the floor during their six-month transit but the hab is not entirely alone on its journey just ahead of it is a second erv identical to the first launched just a few weeks prior to the harp it will prepare the way for a second human crew that will follow two years later it can also function as a backup for the first mission if anything should go wrong [Music] on the sixth month of the flight the crew will gaze upon an alien world this is the new frontier after days in orbit and satisfied with the landing conditions the crew will receive final word from mission control on earth all systems are go for entry descent landing three two one it will be a tense 40 minutes before people back on earth get the signal from mars and know if everything has gone well [Music] okay 75 feet that's looking good down a half contact light okay engine stopped [Applause] for more than 500 days the astronauts will live on mars and embark on one of the greatest journeys of discovery in the history of science will they find life or the fossilized remains of past life [Music] such a discovery could tell us whether our solar system has seen more than one genesis and answer the ultimate question are we alone in any case these explorers will be learning how feasible the colonization of mars really is and whether or not mankind has a future among the stars then when the time comes and the window for earth return opens the crew will climb into their earth return vehicle and head home [Music] they will arrive home heroes the first to stretch the limit of man's expanse from one planet to another their names added to the list of great explorers of new worlds in their footsteps others will follow what began as a trickle is free to rise into a deluge of humankind sweeping over a once barren land and transforming it into a viable new world when baker and zubrin presented mars direct to their bosses at martin they expected the worst to their surprise management was excited about it they liked the fact that everything needed was relatively simple and near-term as time went on martin marietta embraced mars direct as their creation and put bob and i on an airplane to several nasa centers to present mars direct and try to build some momentum for it baker and zubrin flew to the marshall space flight center in huntsville alabama this had been one of the original design hubs for the apollo moon landings but recently many of the engineers had become demoralized by the failure of nasa's sei program tag team style baker and zubrin presented their alternative mission architecture the response was thrilling the old school apollo crowd embraced it this was a plan that actually made sense and was within reach baker and i gave a number of briefings the first was at the marshall space flight center next was at johnson these people were incredibly excited [Applause] over the next few weeks zubrin and baker were flown around the country pitching to all branches of nasa and everywhere they went the response was electric the plan was standing up to scrutiny and groups all over nasa were converting to mars direct their tour culminated in a public presentation to the national space society the crowd gave the two aerospace engineers a standing ovation [Music] [Applause] [Music] [Applause] [Music] a week later the story was in newspapers around the country [Music] the counter-attack was beginning to form within nasa the space station teams and many in the advanced propulsion groups were against the idea since mars direct didn't need their programmes they felt under threat as quickly as doors opened for zubrin and baker they began to close nasa didn't want to pursue a mars mission at that time they didn't want to be derailed by a bunch of mars fanatics that thought that their idea of what nasa should do should overwhelm what nasa thought nasa should do what we did in mars direct was literally come up with the leanest solution the one that involved the least spending on an assortment of technologies and infrastructural elements including for example we made no use whatsoever of the international space station and so people involved in all those programs were very upset because we were showing that you could go to mars without their program being required they felt that we were de-justifying them the nasa administration rejected mars direct the two engineers were outsiders again but zubrin remained determined bob had grabbed hold of it and i could see that it was his and no matter what i did he was going to do what he was going to do and he was going to be a proponent for it and push it and i really saw my role sort of evaporate it's a little bit like being a a dim planet next to a bright star around him in terms of his enthusiasm and you really can't compete with that all you can do is decide how you're going to deal with it by february 1991 baker quit martin to start his own firm [Music] zubrin battled on for the next year and a half zubrin tried to get nasa to pay attention giving speeches writing papers but mars direct's time seemed to have passed but then in 1992 a new administration came into power at nasa and zubrin saw a second chance i was invited to brief mike griffin who was the associate administrator for space exploration in charge of the whole space exploration initiative he immediately became a very strong supporter of mars direct but before the engineers at nasa would take another look at mars direct they wanted zubrin to prove that producing rocket fuel on mars could work they gave martin marietta a small budget to do an experiment zurin and his team built a machine called the in-situ propellant plant it could take carbon dioxide the dominant gas in the martian atmosphere combine it with a little hydrogen and produce a methane oxygen fuel we did it in three months with a very small team we built a plant that was 94 efficient and no one who actually participated in that effort was actually a real chemical engineer they were all aerospace engineers like me who were simply dabbling in chemistry in order to prove to nasa that 19th century chemical engineering really worked with the experiment to success the administration had zubrin give detailed briefings of the mission plan to the engineers of the johnson space center they liked it but had some problems dave weaver was the lead mission architect there were a number of things that we were concerned about with bob zubrin's mission first of all we thought his estimates of mass were probably too optimistic uh didn't have sufficient margins for a variety of things not the least of which would be things like provisions for the crew the amount of water that would be required we thought his ascent vehicle was very large which meant his power requirements his propellant requirements were much larger than needed to be his trip times out were too long and that for very little effort you could get him shorter the other problem was the size of his crew he had a four-person crew i think virtually every study that's been done says that a four-person crew for a three-year type of mission is probably not realistic weaver took zubrin into his office and the two men worked out compromise mission architecture first weaver wanted three launches for every mission instead of two the first year three ships would launch a mav mars ascent vehicle an unoccupied hab and an erv earth return vehicle the harb and mav would land on the surface and begin producing fuel for the return flight and air for the crew these craft would spend two solitary years on mars allowing nasa to test all of the systems before sending a human crew then in the third year three more ships would launch this time with the hab occupied by astronauts the other two ships are for a future mission and less needed as a backup for this crew once on mars the team could also utilize the first half then after a year and a half stay the crew would climb aboard their small capsule and rendezvous with the return ship this ship would carry them back home in a roomier environment than zubrin's erv zubrin called the plan mars semi-direct nasa called it the design reference mission they had a larger crew than we had they had bigger ships they had more equipment they had heavier equipment so they had to do the mission in three launches instead of two but it was done with the same principles of mars direct the plan was subjected to the same cost analysis that tagged the 90-day report with a 450 billion dollar price tag the design reference mission came back at a fraction of the cost 55 billion spread out over 10 years it could be done within nasa's existing budget the plan made the cover of newsweek here was a mission architecture that was affordable and could be done today with existing technology but nasa's astronauts have not left low earth orbit since [Music] with the completion of the international space station and the retiring of the space shuttle program a debate rages over the future of space exploration should nasa continue to focus on low earth orbit developing technologies for the future or should nasa have a goal like it did in the 1960s with apollo the way we got to the moon was by a presidential imperative that demanded that nasa get to the moon within a decade so nasa was forced to sit down design a plan for how to do that and then fly the mission since that time without the presence of a driving imperative we engage in basically a random set of constituency-driven programs which are justified ad hoc afterwards by the argument that they could prove useful at some time in the future when you actually have a plan to go somewhere i think nasa has focused on a steady process where the government can't just pull the plug on their funding i think the apollo cancellation was very traumatic for nasa and it really transformed nasa from what it was in the 60s to more of what it is now if you have a singular program like going to mars then it is very vulnerable to having its funding pulled nasa must be destination driven it is the only thing that allows the agency to be productive nasa was a hundred times more productive when it was destination driven than in the period there has not been and we have stagnated in nasa since 1973 30 years more than a generation has been wasted [Music] the american space program has been stagnant for 30 years there is a once-in-a-generation shot right now to get it moving again by giving it a goal that'll take it somewhere so the stakes today are high if you ask me if i am nervous right now i am [Music] dr zuberman why is nasa stuck in low earth orbit the problem with nasa's lack of current achievement is not money the problem is lack of focus it's lack of a goal it shouldn't be humans to mars in 50 years it should be humans to mars in 10. we can do this we do not need gigantic nuclear electric spaceships to send people to mars that that is pork it's nonsense the primary question i get from the american people is why aren't we doing this there's a big sense of disappointment almost verging on a sense of betrayal the purpose of spaceships is to actually travel across space and go to new worlds not to hang out in space and observe the health effects from doing so dr zubrin in your testimony you were very passionate but you also were mad you're mad we haven't done this or that this vision has been stolen from a generation i guess you could say that it's like columbus coming back from the new world and ferdinand and isabella's saying ass so what forget it burn the ships okay you know that's what has happened in this country [Music] we've won our point that there needs to be a destination what we need the point we need to win on now is the destination needs to be mars and it needs to be sued [Music] the movement to send humans to mars in the near term began at the university of colorado in 1978 a graduate student in astro geophysics named chris mckay gave a small seminar on the possibility of introducing life to mars i got interested in mars in graduate school i entered graduate school the same year that viking landed on mars and sent back these images and sent back data that showed all the elements needed for life are here on this planet and yet there's no life here oh that's odd sort of the lights are on and nobody's home and i thought well that's curious so some of my other grad students and i we sort of got together to talk about well if there's no life on mars now could we put life there and that evolved also into the question was maybe there was life in the past and we could find fossils evidence of it well how would you do that well you do that by sending people there together with fellow graduate students the group decided to put together a small conference to discuss the matter of human mars exploration [Music] we basically just started a forum we invited everybody from all the nasa centers and from all the universities were involved in it and they all came and it was it really was in retrospect i realized a very important step toward building a consensus for human exploration of mars in 1996 i published my first book the case for mars the response was phenomenal i got 4 000 letters from all over the world i had parisian bankers and 12 year old kids in poland and firemen from saskatoon and astronauts and they're all writing me and saying how do we make this happen bob zubrin came to the third mars conference and got very much involved he was willing and interested in forming a society forming a group and organizing he said look if we could pull these people together we can get them to work together we could have a force that could actually make humans to mars happen the group formed the mars society robert zubrin became the president they held their first convention in 1998. the convention was just magic we had no idea how many people were coming they were there not just from the united states and canada and europe they were there from israel they were there from mozambique they were there from new zealand it was astonishing since its inception the mars society has attracted members worldwide derek shannon is the head of the southern california chapter he's met with political leaders from all over the country if you make them look at the whole mars vision in historical terms it becomes a much easier sell how will the martians remember our century they're probably not going to remember our deficit our wars our health care those will be footnotes what they'll remember is that out of all of human history there came a generation that decided to take this amazing step out into space and if you tell politicians that they're the ones whose names actually get to be remembered that's when hopefully the space program starts going somewhere [Music] in order to further the knowledge necessary for a manned mission to the red planet the mars society has been building research stations around the globe all of them based on the design of zubrin's hab module [Music] most recently the society set up a desert research station in utah here international researchers and aerospace students come to do experiments under the harsh desert conditions and learn what's necessary to keep a mars crew alive and productive basically what we're doing here is undergoing analog studies crews of up to six people at a time come together to live in a full simulation environment for up to 14 days so what that means is every time we go outside the hab people have to don space suits after depressurized when we go outside they're called extra vehicular activities they can only be of a certain duration due to the air supply we have to recycle all our water and basically have our own food as well [Music] it's great to fantasize but it's another thing when you have to put it together when the nuts have to fit the bolts like the apollo missions to the moon sending human beings to mars will mean putting people in harm's way there are many dangers in outer space and many things could go wrong a serious equipment breakdown could doom the crew to their deaths some argue that the risk of failure is simply too high you know back in the days when medieval man was looking out from europe thinking about exploring the world the world was unknown and map makers populated their maps with dracus we've got the same thing today there are people who are afraid to go out into space and they've populated their maps of the solar system with dragons you know we've got cosmic radiation we've got zero gravity we've got back contamination but these are dragons that we can take on there are two kinds of radiation astronauts must contend with in outer space solar flares and cosmic rays [Music] solar flares are floods of protons that burst from the sun at irregular intervals and would be dangerous to an unshielded human crew we are not ready to send humans to mars right now we've gotta know a lot more about radiation and radiation mitigation one of the apollo flights barely missed like by a week a major solar event if it had gone off when the apollo astronauts were on the way back and forth to the moon they would have gotten their entire lifetime radiation dose in that one mission that's just one solar flare so that's why we worry about this in the mars direct plan zubrin envisions a central insulated core where a crew can retreat to while the radiation passes by the core would be surrounded by all the provisions of the mission this should stop any harmful dose of radiation from reaching the astronauts basically you use your pantry as your storm shelter so a solar flare happens the alarm bell rings the crew goes into the storm shelter they stay in there cramped up pretty tight for a few hours until the oil clear rings and they come out this is going to happen once it might happen twice in the course of the mission the second type of radiation is cosmic rays this constant rain of charged particles comes from interstellar space and cannot be avoided without many meters of shielding we can experience some of this type of radiation on earth at high altitudes airline pilots who spend their careers flying high in the atmosphere can receive almost as much of this radiation throughout their life as a mars astronaut would on a two and a half year mission it's a long trip it's a six month trip there six month trip back is probably a year on the surface that's a lot of radiation the best estimates are that the magnitude of that dose is not that great perhaps 60 rim of radiation scattered over two and a half years now 60 ram of radiation delivered over a long period of time like that would not create any noticeable effects at all it would though it is believed increase your statistical risk of getting cancer at some point later in your life by about one percent right now if you're an average american and you do not smoke you have a 20 chance you're going to die of cancer this would make it 21. if you're an average american smoker it's 40. so in fact if you recruited the mars crew out of smokers and sent them to mars without their tobacco you would be reducing their chance of getting cancer with the immense distance from earth never before experienced by a human being with the constant dangers of outer space surrounding their small life-sustaining craft and with nowhere else to go the psychological impact on a crew could be severe fear is real i mean it would be to me abnormal for a person to not feel the fear of getting on a rocket and launching into space and going to mars so i think fear is a very normal thing that all astronauts in fact are supposed to have and i would be afraid to fly with someone who does not have fear some psychologists worry that cabin fever could set in and the crew might literally go crazy the human mars mission is a more rigorous and difficult condition than most of us experience in daily life but it is hardly more difficult situation than many people have endured throughout human history we could compare the mars crew to the crew of 19th century or prior sailing vessels many of whom were away from home for three years or more than three years under conditions in which they're eating extremely bad food without any medical knowledge to support their health commanded by brutal officers in every respect the crew of a human mars mission with the full support of mission support in the whole world cheering for them and great rewards awaiting for them in life upon their return is in a vastly superior condition the mars direct crew will spend most of their time inside the two-story hab carefully designed to promote psychological well-being despite the confinement the space where i think everybody would spend the most time you know just like a lot of homes on earth would be the galley wardroom area there would be chairs a table some kind of large screen for entertainment you would have individual state rooms about four or five feet wide the ability for them to communicate with loved ones with colleagues on earth i think will be almost unlimited amaz crew will need to be carefully chosen and thoroughly tested to ensure their ability to handle the extreme isolation [Music] john young who went to the moon used to say that he could cover uh the earth by just lifting his thumb up to up to it and he says that when you go to mars you are going to redefine the concept of loneliness and so it is very important that the crew be well balanced and well chosen so that they can support each other whoever gets picked to go they will have to learn to live together for two and a half years if you put out a call for volunteers for the first crew to mars they'd be lined up coast to coast most people recognize what's left after you go is the good you left behind and to take part in adventure this character such a historic character of extending the reach of the human species this is something of immortal significance [Music] one of the most bogus threats associated with the mars mission is the so-called back contamination issue which is this notion that you go to mars and discover these virulent disease organisms that you bring back to earth and destroy all life on earth if we discover life on mars one fear is that our earth biology will have no defense against possible martian pathogens some argue that missions to mars cannot be risked until we can prove mars is free from harmful contaminants this is completely nonsensical there's natural transfer of material from mars to earth all the time we get around 500 kilograms of unsterilized martian rocks landing on earth every year and they have been doing so for the past three four billion years and so if there were martian organisms that could contaminate the earth they've already done so although the prospect of martian diseases seems remote lawmakers have required that nasa create elaborate protocol to ensure that any extraterrestrial material stays contained and like the apollo astronauts who spent 17 days in quarantine after their return from a sterile moon a mars crew will have to be thoroughly tested for any harmful martian pathogens the probability is infinitesimally tiny but nevertheless this is our home planet and it's extremely important and we have to protect it the idea of a pathogen on mars is clearly ridiculous because there is no megafauna or megaflora on mars for pathogens to infect so it is impossible to propose a credible life cycle for a martian pathogen the diseases that afflict us have been co-evolving with us and our ancestors and near relatives for the past three billion years and they are specifically designed to live inside the habitat of the human body and to overcome its defenses and they've been engaged in an arms race with the human defenses for those three billion years this is why humans do not get diseases from distantly related species for example i don't know of any person who has ever contracted dutch elm disease you know and trees don't get colds [Music] when the first mars lander touches down the crew will be staring out at a new world a place that in four billion years no eyes have ever seen [Music] the crew won't be alone millions of television viewers back home will be watching as the first man or woman places their footprint into the rust-colored soil the crew will savor these moments for here someday a new branch of civilization might begin and future martians will remember and celebrate this day [Music] there is much for the crew to do and explore one of their main mission objectives will be to search for signs of microscopic life to do this they will follow the ancient water flows for on earth where there is water there is life to help the crew in their search they will have a pressurized rover that allows them to explore in a comfortable shirt sleeve environment this means the crew can examine a vast area around the landing site during their 18-month stay and there is much to explore mars has 58 different kinds of topography and a surface area equivalent to all the continents of earth combined [Music] if these explorers can uncover the fossilized remnants of indigenous martian life they will redefine mankind's understanding of its place in the universe [Music] for if life arose separately on a planet so close to our own it strongly suggests that the universe is a biologically rich place and full of life [Music] for some the ultimate question of mars though is will there be human settlements on the planet will mars become a new branch of human civilization as each subsequent mars mission explores a wider and wider area of the planet over several years an ideal site for a base will be found probably one with a thermal vent that can supply water and power at that point several halves will be landed in this one spot with crews that plan to stay for four eight or even twelve years the habs will be interconnected and a permanent human presence on mars will be established this scientific community will have to learn to become self-sufficient to be able to survive on mars without supplies constantly being sent from earth but unlike any other planet in the solar system besides earth mars has all of the fundamentals needed to make this possible its 24-hour and 37-minute day is critical for growing plants it has all of the elements necessary for creating building materials like plastics metals and glass and it has oceans of water frozen into the soil if we can develop this craft of living on mars then mars becomes inhabitable not immediately physically but intellectually i mean look what determines whether an environment is habitable or not is colorado habitable we're not naturally adapted to live in colorado we're tropical animals no one could survive a single winter night here without technology such as clothing efficient use of fire we invented our way into becoming people that could colonize such hostile environments eventually with a lot of ingenuity and invention the scientists will learn to live off the land they will grow crops in the iron rich but potassium poor soil and they will produce oxygen and energy from the water and atmosphere sooner or later children will be born the first true martians they will grow up to see mars as their home with time more and more people will arrive these won't only be scientists but settlers people who plan to stay they may come for all kinds of reasons but to them mars will be a chance to start over to build a new life for [Music] themselves well of human social thought is not exhausted by the present age and i don't think we'll ever be exhausted there will always be people with new ideas on how humans should live together with mars so far away the hold of earth governments on their colonies will be tenuous the martians will need to govern themselves [Music] mars is not going to be a utopia mars is going to be a lab it's an open frontier it's a place where things are going to be tried out i think we'll see a lot of noble experiments on mars perhaps some of these martian colonies with their novel ideas based on the best thought the 21st century has to offer maybe they'll find ways in which humans create society that are more humane and offer more opportunity for human potential [Music] the ultimate dream of the martians will be to terraform their planet to make mars as hospitable as earth this may not be as big a fantasy as it seems here we are on earth a world that's very sophisticated and developed and complete and anything we do is just a subtraction because we live in such a biologically rich planet when we go to mars we have an opportunity that we don't have on earth here's a planet that's died here's a world that's not full of biology probably doesn't have any at all well there we can actually do something to help once there are large human settlements on mars that have significant industrial capability we could actually start addressing ourselves to the question of transforming the martian environment itself terraforming mars as it's called because mars was once a warm and wet planet and it could be made so again through human engineering efforts with daytime temperatures in the martian tropical zone averaging around zero degrees centigrade and with an atmosphere only one percent as thick as earth's exposure to these elements by a human without a spacesuit would be instantly fatal the first step to terraforming mars and bringing it back to life will be for the martian colonists to warm up their planet well we know how to warm up planets we're doing it on earth by putting gases in the atmosphere on earth it's not a good idea to warm up the planet the temperature was just fine thank you we don't need it any warmer here but in principle if you could trap the sunlight reaching mars today every single photon that's hitting mars mars would warm up in about 10 years well obviously you can't trap every single photon that's hitting mars but you can trap about 10 percent of them with the greenhouse effect so that would imply that mars could warm up in about 100 years a hundred years is a long time but it's not astronomically long one idea is to build small automated factories that produce super greenhouse gases with no ozone depleting side effects although these gases would be unwelcome on earth for the martians there would be an efficient way to trap heat then within a few decades we would raise mars by more than 10 degrees centigrade and if you did that that would cause massive amounts of carbon dioxide that is currently absorbed into the martian soil to start to outgas carbon dioxide is also a natural greenhouse gas as it builds up in the atmosphere more and more heat will be trapped which will in turn cause more co2 to outgas the process will become automatic and as the atmosphere thickens mars will eventually reach a state of equilibrium and stay warm naturally the rise in air pressure would mean that the human colonists could discard their pressure suits and walk around the surface of mars carrying only a supply of oxygen and as the temperatures rise on mars water frozen into the soil will begin to melt out and for the second time in its history mars would have liquid water on its surface dry martian rivers will start to flow seas will rise and there will be rain clouds in the skies [Music] the return of mars to its warm and wet stage will make it a fertile environment for life any indigenous martian organisms lying dormant will begin to grow and mars will be full of martians [Music] if no native life emerges or that life is all dead then humans could begin addressing the idea of bringing life from earth at first it would be simple organisms perhaps genetically engineered that would thrive in the martian environment then more complex plants could be introduced the plants would be right at home in the carbon dioxide atmosphere and with no competition and a whole planet to cover they could transform mars into a green world [Music] warming mars so that it sustains life is rapid but then the slow process of making the atmosphere breathable for humans and animals starts and that's done by plants although the process will happen naturally if the colonists can't find a quicker way it will take tens of thousands of years this is a philosophical debate many people think the universe has a big sign on it that says do not touch leave it alone it was made this way it is not in our purview as human beings to change anything i can respect that view although i disagree with it i think the universe has a big sign on it that says go forth and spread life because when i look around the universe i think life is the most amazing thing we see it is just incredible and we human beings are uniquely positioned to help spread life from this little tiny planet which it seems to have started on beyond and that's our gift earth's gift to the universe i think is the gift of life [Music] [Music] this scheme for terraforming mars is based on 20th century notions of engineering i don't think it is how mars will actually be terraformed what you have here is a 20th century mind trying to address a 22nd century problem and so i think mars will be terraformed by the 23rd century not by the 33rd by the 23rd things that would seem utterly fantastical to us is how it will actually be done but it'll be done [Music] we're at a crossroads today we either muster the courage to go or we risk the possibility of stagnation in the key the exploration of the solar system and expanding of life through the rest of our solar system and some day beyond is the kind of thing that will keep our civilization going we're explorers by nature eventually we will go to the stars the question is when will we start i think a man mars mission could happen within 15 years some days i'm very optimistic i think we can do it in 10 maybe 15 years other days i see the all the political things that go into the space program i look back under 30 years we've been bogged down and i and i get more negative about and i say it's going to be another three decades or four decades i would be surprised if we got to mars prior to uh 2025 or 2030 uh in may of 2018 understanding the various political obstacles that exist and what we need to fight through to get the program started i believe that we will be on mars by 2020. [Music] you have to believe in hope you have to believe in the future [Music] there are more and more people coming around to the point of view that a positive future for humanity requires human expansion into space we will eventually break through the forces of inertia that have been holding this thing back so so so so [Music] so so [Music] [Music] [Music] [Applause] [Music] do [Music] [Applause] [Music] so [Music] [Applause] [Music] [Applause] [Music] do [Music] do [Music] [Music] do do [Music] do [Music] you

Channel: How the Universe Works

Views: 1,112,274

Keywords: knowledge, Science, The Universe, Space, Solar System, Astronomy, documentary, cosmos, planets, stars, planetary, how the universe works, Secrets of the Universe, Formation, Earth, Space Discovery Documentary, how the universe works formation and evolution

Id: jMjAhdddsWQ

Length: 173min 18sec (10398 seconds)

Published: Fri Sep 09 2022