The Secrets Of The Gas Giants: Jupiter, Saturn | Beyond Our Earth

foreign Century came to a close the Voyager 1 probe became the farthest object from Earth forged by human hands we're really going into the unknown but nearly 15 years later it's achieved yet another Milestone our Emissary was the first to touch Interstellar space the moment was the crescendo to a saga featuring The Solar System's four outermost planets we have the ignition [Music] 1977 the twin Voyager probes departed to explore the Giants how do gas giant planets like Jupiter Saturn Uranus Neptune actually form in the first place some of the things that were found were so surprising they'd never been thought of when the spacecraft was being planned voyages paved the way for a new era of robotic investigation it was tantalizing but left so many questions unanswered that we just had to go back [Music] some distant moons May hold the greatest potential for life beyond Earth if I had to bet on a best candidate for life in our solar system I would pick Enceladus now we are scouring our system's outermost regions hoping to discover a new mystery planet we're looking for a needle and a haystack but the needle looks like hay that's why planet nine hasn't been fined yet if it is there [Music] during the early formation of our solar system four small rocky worlds assembled where the radiation of an infant sun was strong enough to push away light gases and destroy all ice but with great enough distance hydrogen helium and Ice is like water and methane were plentiful in this region four giants were born Jupiter Saturn Uranus and Neptune through their gravity in the early history of our solar system these gas giants have vacuumed up all of the available gas Humanity's curiosity extended to these Distant Worlds we'd explored the inner worlds of the solar system we'd gone to Mercury it would been to Venus we'd been to Mars but the big worlds of Jupiter Saturn Uranus Neptune they really beckoned to the scientific community an expedition to the Giants would require crossing a proto-planetary graveyard a ring of asteroids leftovers from the Solar System's formation 160 million kilometers beyond Earth's orbit we had to Traverse the boundary in between Mars and Jupiter the asteroid belt we only had some basic telescopic observations of some of these objects out there and was it going to be a region of space that we could travel through [Music] in 1972 NASA's Pioneer 10 became the first spacecraft to enter the asteroid belt the asteroid belt in our popular imaginings is a rubble strewn region of space mountainous size objects crashing together in slow motion it's nothing like that I think that's an interesting thing this one piece will make 52 layers watch on mobile devices or the big screen all for free no subscription required [Music] scientists estimated a 1 in 10 chance that the spacecraft would suffer a serious Collision there's a lot of rock out there but it is spread over an enormous ring or volume of space collisions do occur but they are not as frequent as you might imagine seven months after entering Pioneer emerged triumphant having a spacecraft like the Pioneers extend their reach out into the solar system was again another important stepping stone and our exploration of the universe by Year's End the probe completed a flyby of Jupiter using the planet's gravity to escape the solar system [Music] Pioneer 10 remained our most distant spacecraft until 1998. great deal that is most interesting in our solar system was beyond our reach until Pioneer 10 showed us the way in the 1960s engineers at NASA's jet propulsion laboratory noted an imminent alignment of the outer planets a spacecraft would be able to harness the gravity of each and swing from one to the next using minimal amounts of fuel it was recognized that you could do a grand tour the idea of rendezvousing with more than one planet but if NASA missed their chance the alignment wouldn't reoccur for almost two centuries [Music] Voyager was an Epoch making moment in the annals of space flight twin probes were crafted Voyager 1 and Voyager 2. together they would provide unprecedented access to the outer reaches of our solar system it was going to be the first time that we had pictures of such incredible detail of Those Distant bodies let's measure these things in great detail but moreover they're going to keep going and let's build them for the long term let's see how long they can last 1970s technology would have to endure the harsh environment of space for decades the Voyager spacecraft by today's standards are quite basic Vehicles they had old television cameras on board not too different from what might have been used in a television Studio their recording systems were eight-track tape nevertheless the equipment was capable of capturing essential details of the mission targets [Music] the modern ships that sailed to the planets are unmanned they are beautifully constructed semi-intelligent robots [Music] each Voyager probe also carried greetings from Humanity [Music] the legendary scientists astronomer and Communicator Carl Sagan decided to send a cultural object along with the scientific missions on the two voyages and this was the famous golden records I sent greetings on behalf of the people of our planet into the universe seeking only peace and friendship to teach if we are called upon to be taught if we are fortunate and it is with humility and hope that we take this step [Music] normally it's a message for any alien species who have to find them but actually it's a message to us as humans that we have something a little bit special on our planet that we would like to send out into space if extraterrestrial life could decipher the instructions to play it the record would reveal 115 images 90 minutes of music and greetings in 55 different languages [Music] three two one we have the ignition and we have liftoff of the Titan Center carrying the first of two Voyager spacecraft to extend man senses farther into the solar system than ever before Voyager 2 was launched first on August 20th 1977. this is the most exciting mission that I've ever worked with we're really going into the unknown it's going to be one of the most scientifically productive of the quieter emissions Voyager 1 followed two weeks later in less than two years each arrived at the first proverbial stop on their grand voyage [Music] the largest of all the gas giants Jupiter contains two and a half times the mass of our Solar System's other planets combined [Music] Jupiter formed from all these little globules of matter basically colliding together in the very early days of their solar system formation the infant World hungrily swallowed nearby asteroids and comets bulking its mass even further eventually when it cooled down it was able to accumulate gases so now it has the sort of a solid core and then this huge amount of gas around it Jupiter is truly the king of the planets it's the dominant force in our solar system except for the Sun Pioneer 10 had captured our first close-up images of Jupiter but the Voyages would expose even more of the planet's secrets [Music] we knew there was something going on when moisture got close it saw a very complex place it saw weather patterns more similar to here on Earth one of the key targets Jupiter's Great Red Spot it's like a tropical Cyclone but huge and it was first observed almost 400 years ago just to Simply exist so long it's fascinating and it's still not completely well understood in the 19th century the Great Red Spot stretched three Earths across but when the Voyages visited it had decreased to two the scale of Jupiter in particular I think is one of the more striking reminders of just how small we are when you look at features and realize the entire Earth can fit within with space despair it really is the Land of the Giants while Jupiter's massive Cyclone had been known for centuries Voyager 1 revealed a completely new feature Rings like Saturn [Music] so faint that no one had spotted them earlier the Rings were likely formed by Jupiter's moons shedding dust which settled into their parents orbit future discoveries would reveal rings around every gas giant in our solar system Saturn turned from being the solitary Jewel to actually being just one of a whole family of ringed planets in our solar system the Voyages also investigated some of Jupiter's natural satellites the moons of Jupiter pivotal in human history because of Galileo's discovery of the four large moons of Jupiter that it kind of turned our view of the solar system on its head Galileo's 1610 Revelation helped disprove the geocentric model of the universe Earth the other planets and their satellites all moved in orbit around the sun innermost Galilean Moon IO is a hellish world home to as many as 400 volcanoes the volcanoes are spewing sulfur dioxide and they're actually producing a ton of sulfur dioxide per second the Voyages captured a surface covered in lava and sulfur in part caused by the moon's close elliptical orbit around such a massive body normally a moon wouldn't have such an active core but it's actually being caused to have an active core by Jupiter itself [Music] gravitational tug of Jupiter drives Rocky Tides i o surface bulges in and out by as much as 100 meters each cycle and the frictional forces keep its interior warm and subsurface Rock liquid it is the most volcanically active body in the solar system because of the internal pressures and temperature that that generates but it's the smallest of the Galilean moons Europa which holds the most interest s believe Europa has a subsurface ocean with more water than exists on Earth Europa has liquid oceans under its heavy ice shell we can see the effects of currents in that ocean convective currents flowing to the surface and breaking up the ice it's a circulating ocean and where there is water there is the opportunity for life we're talking now about the potential of Europa being a living world we've got liquid water we've got a strong energy source and organic chemistry on Earth those same ingredients in less than a billion years gave rise to life [Music] closer images of Jupiter and its moons would have to wait until the end of the 20th century the Galileo spacecraft deployed from shuttle Atlantis in 1989. it's been a long time coming but you have a go for on its way to another world to fly safe but its journey to Jupiter would span six years [Music] on Route Galileo witnessed an extraterrestrial Collision [Music] 1994 the spacecraft watched as the comet Shoemaker Levy 9 was torn apart by Jupiter's immense gravity sometimes there's a lot of luck in space exploration Celestial mechanics came together to give us one of the most spectacular events in our solar system many thought that Jupiter's clouds would simply swallow the pieces up however as each fragment crashed into the atmosphere they released more energy than Earth's entire nuclear Arsenal oh Galileo was able to capture the distinct holes in the distinct impact craters and that the biggest one was thousands and thousands of kilometers wide the Collision of Shoemaker Levy 9 demonstrated how Jupiter's gravitational presence affects our own world with Jupiter we have this gravitational bully that has influenced our own history as much as out of all the other planets gravity pull things into it it is very likely that it has shielded us from password in Comet impacts which may help understand why life formed here under the Galileo mission two explorers ventured to Jupiter a small probe accompanied the main spacecraft Bound for a brief but crucial encounter with the planet's atmosphere each arrived in December 1995. but while Galileo entered orbit it Pro dropped beneath Jupiter's Cloud tops the Galileo probe was actually able to plunge down through that atmosphere and see if there was water the probe quickly hurtled to a final measured depth of 180 kilometers did it rain from the clouds of Jupiter what were the temperatures what were the pressures like was there lightning in that atmosphere and along the way it discovered all of those things proving the theories that we'd had about this Dynamic world for the very first time after loss of signal the probe was vaporized in 2003 following its 35th orbit a dying Galileo was steered into Jupiter's atmosphere meeting the same fate the craft had not been sterilized prior to launch this act of Destruction would ensure no life had it survived the journey could contaminate Jupiter's moons [Music] for the next 13 years we could only study Jupiter from afar ignition and liftoff of the atlas V with Juno on a trek to Jupiter a planetary piece of the puzzle on the beginning of our solar system 2016 the solar-powered Juno spacecraft arrived and settled into a polar orbit the purpose of the Juno spacecraft was not to show us the Clouds Of Jupiter once more to actually understand more about what's going on inside the planet how do gas giant planets like Jupiter actually form in the first place we don't know how big worlds like that actually get built on each of its highly elliptical orbits Juno passed Jupiter with only 8 000 kilometers to spare this is akin to skimming around a basketball just one centimeter from the surface but which we're doing this to tens of thousands of kilometers per hour no allowed us to understand what hides beneath the clouds down to the core itself we've got a Weebly wobbly core in the interior of Jupiter generating this enormous magnetic field a magnetic field that is some 20 000 times greater than the Earth [Music] Juno was actually built with a significant shielding just to prevent its Electronics being Fried by these close approaches inside Jupiter it ceases to be a gas giant the hydrogen becomes compressed into liquid and it takes on metallic properties Juno has helped us understand that structure in incredible detail [Music] as we enter the 1980s both voyages approached their next Target foreign the second largest planet in our system named after the Roman God of Agriculture the ringed World Saturn Saturn has been observed in the night sky since Antiquity and its rings revealed not long after the first telescopes were crafted when Galileo turned his telescope towards Saturn he was really confused no one in humanity knew that a planet could have rings around it the best he could come up with trying to describe Saturn was that it looked like it had ears [Music] Dutch astronomer Christian Huygens employed a more powerful telescope of his own design and deduced that Galileo's ears were actually a system of rings [Music] each Voyager spacecraft arrived at Saturn months apart the Voyages revealed a huge amount about Saturn they discovered rings that had not been detected from the Earth Rings 200 000 kilometers across but only maybe 10 meters thick an average overall [Music] they were able to resolve the Rings into their component parts little chunks of rock and ice dust grains up to Boulders as large as mountains racing around the planet at 80 000 kilometers per hour with its own strange magnetic field suspending dust particles above and below the Rings in the last day we have learned a great deal about Saturn surrounding rings and moons from the dramatic pictures that have been brought back by the Voyager 2 spacecraft voyages new data on the Rings they're puzzling Origins became a little clearer the rings of Saturn have been a mystery for many years in terms of how they came to be there had they formed with the planet itself or did they materialize later Saturn's immense gravity destroying a smaller Wayward body perhaps it was a relatively recent event in which an ice Moon got too close to the planet to stay intact and became broken up into rings Christian Huygens also discovered Saturn's largest moon Titan in 1655 later that Century an Italian French astronomer by the name of Jean Dominique Cassini discovered four more in 1997 NASA Esa and the Italian space agency launched their joint exploratory Mission named after both men Cassini Huygens in many ways the Cassini Huygens Mission grew out of the Voyager missions because what we saw in the vicinity of Saturn was utterly tantalizing the mission consisted of two separate spacecraft the Cassini probe which is a NASA project and the Huygens probe which actually came from Europe these two teams from different sides of the Atlantic could achieve so much more I think than either projects would have done alone [Music] Vermeer highlights in the exploration of the outer solar system has to be the Cassini haugens probes we've learned so much about not only SATs and the Beautiful ring planet its atmosphere its rings but also its many many moons which are really fascinating [Music] an extraordinary Mission 13 years of absolutely marvelous Discovery some of the things that were found were so surprising they'd never been thought of when the spacecraft was being planned Cassini Huygens arrived at Saturn after a seven year Journey [Music] yeah the first mission to orbit the planet Cassini provided unprecedented detail of Saturn's rings by flying through them Mission Control had to precisely navigate The Craft through the debris tensions were high on every pass what will it encounter as it passes through that ring what effects will there be on the electronics of the system are there particles or small objects with which the spacecraft will collide and be destroyed that requires some very very clever use of orbital mechanics we saw evidence for essentially water falling out of the Rings something like 40 tons per second the Rings themselves are actually raining onto the planet's surface Cassini was able to observe the first hurricane-like structure on Saturn the Great White Spot and watch a hexagonal atmospheric structure at Saturn's North Pole change from Blue to gold the hexagonal feature that's at the North Pole of Saturn is due to a massive hurricane and it's about 50 times more massive than any hurricanes we get on Earth [Music] on Earth that there are on these gas giants something we never would have thought of [Music] on July 19 2013 the Cassini spacecraft image Saturn and its entire ring system during an eclipse of the sun one of the most spectacular images it returned was actually from The Far Side of the planet looking back towards Saturn with the sun lining it up from behind spanning over 650 000 kilometers the picture detailed Saturn's second outermost ring composed of fine icy particles DeGraff also features a pin prick of light the Earth 1.4 billion kilometers away so knew that the Earth was going to be in that shot and decided to say to everybody on that day at that moment go outside and look towards the skies because your photons will be emanating from the surface of the Earth and received by the Cassini spacecraft [Music] yeah during its Mission Cassini snapped images of many saturnian moons but one held the spacecraft's focus Enceladus is Saturn's sixth largest moon its distinctive sudden Stripes sit atop a saltwater ocean buried kilometers below is high sea surface close inspection by the Cassini spacecraft showed cracks in that ice and showed water geysers spraying out from a subsurface ocean these these eruptions fling material into space and it means that you don't have to land on this moon to access this ocean you just wait for a geyser to erupt and Cassini was flown through those geysers who was able to taste those Waters and found that the water was warmer than we expected it to be and it was full of both simple and complex organic chemistry it suggested that there could be thermal vents at the bottom of an ocean where life could Thrive if I had to bet on a best candidate for life in our solar system I think I would pick Enceladus if we can actually go to Enceladus in the future and send drones under the water and see what's down there I think that will be an absolute Watershed for our understanding of whether life could potentially exist in our solar system life really is common out there or the conditions for life are coming out there and if this little cold place around Saturn has it it's probably common decades before Cassini Voyager 1's brief encounter with Saturn's largest moon Titan wetted our appetite without a question the images that were returned this morning revealed a world unlike any of the others that we've seen it was tantalizing it's all the things that we hadn't known before but left so many questions unanswered that we just had to go back secrets of Titan were buried beneath this thick hazy atmosphere it's opaque for the same reasons that we get this Haze of smog in some of the more populated areas of the world Titan's atmosphere is rich in hydrocarbons mostly ethane and methane and the effect of the sun's radiation on those hydrocarbons is to turn it into a very hazy atmosphere [Music] after deploying from Cassini on December 25th 2004 Huygens began a 22-day journey toward its Target upon arrival Huygens descended for two and a half hours the European Space Agency sent a landing mission to Titan as part of the Cassini mission it's successfully soft landed on the surface and sent back a whole bunch of data first craft to land on an outer solar system body Huygens continued to transmit data for 72 minutes until its batteries were drained and it revealed to us a world that has ice mountains and sand dunes and river-like features not from liquid water flying from the surface but from organic molecules of ethane and methane raining from its clouds flowing across a water ice surface and flowing into vast Lakes primordial it was kind of like a snapshot of what we thought Earth was like three billion years ago when life was just starting to come into play and if life formed on Earth in very similar conditions maybe it's forming or has formed on Titan this is not Life as we know it but it's conceivable that something could be there the chemistry is complex enough that life may form could we recognize it if it did is perhaps another question [Music] [Music] after 20 years in space and 294 orbits of Saturn Cassini was running out of fuel the mission embarked on yet another risky first a journey between Saturn's atmosphere and its rings [Music] the choice was to send Cassini through Saturn's rings through a very small Gap actually and to do this multiple times to learn more about what was there diving through Saturn's rings 22 times Cassini sought to determine their age in 2019 astronomers revealed the answer somewhere between 10 million and 100 million years old a fraction of the age of the four and a half billion year old Planet they encircle and then eventually the final swan song was to send it into Saturn itself for a very scientific ending where it was transmitting important data right until the last second [Music] within the next 45 seconds so will be the spacecraft I'm going to call this the end of mission project manager off the net [Applause] four decades before cassini's demise Voyager 1's mission to Titan ensured a lonely outward path her journey that sent it straight out of the solar system [Music] Voyager 2 carried the responsibility of visiting the remaining planets the ice giants Uranus and Neptune Sir William Herschel first observed Uranus on March 13 1781 though he did not initially identify it as a new planet after all it was the first that had not been known to the ancients [Music] just over two centuries later Voyager 2 approached within 82 000 kilometers of Uranus's Cloud tops [Music] Uranus is an oddity that voyage's eyes were able to show us really a lot of interesting features of very high jet streams racing through its polar regions and equatorial zones and to show a little bit more detail than we can get from here on Earth Voyager 2 studied Uranus's unique atmosphere manipulated by the planet's strange orientation Uranus lies on its side with a tilt approaching 98 Degrees it's thought that an earth-sized object may have collided with Uranus long ago pushing the planet over its atmosphere reaches the lowest temperatures of any planet in our solar system plunging as low as minus 224 degrees Celsius ice giants are so far away from the Sun that they're receiving a really tiny amount of the Sun's light between 100 to a thousandth of the Sun's light Uranus's distinct coloring comes from the presence of methane in its atmosphere which exists in Greater concentrations than in its larger siblings but like all the Giants Uranus has its own system of rings the brightest of the Uranian Rings had been discovered a decade prior aboard the kaiper Airborne Observatory an airliner fitted with an infrared telescope voyager's observations brought the total to 11. Voyager 2 also provided up close images of the moon Miranda one of the strangest bodies yet observed in the solar system when that first of the series of Miranda images came in just where it was supposed to it was that sense of oh my God we did it it looks like a world that has been smashed up torn apart and then put together again really really poorly one half of it is deep curve thoroughs on its side and the other half of it is an average looking pockmart Moon that you would see in orbit around another planet and there they are together they're completely different but they're in the one body [Music] Cliffs that are over 20 kilometers high and the gravity of Miranda is so low you could stand at the top of that 20 kilometer High Cliff look straight down jump off the edge of that Cliff take 20 minutes to reach the bottom you better land on your feet and walk away [Music] in August 1989 Voyager 2 approached the final Target of its Grand voyage Neptune which was first revealed not with a telescope but with mathematics the planet Neptune was discovered by its gravitational pull on the planet Uranus so before we even saw it from the light that it emits we inferred that it would probably exist because the orbit of the other planets were kind of being pulled out of line to speak with Voyager 2 at so great a distance would require a new technical achievement probes like the Voyages are they're very quiet the further you go the bigger and bigger we need to make our receiver dishes to pick that up [Music] 1986 NASA established its deep space Network free communication complexes around the world that improved our ability to capture the weak radio signals from Neptune our job is to send commands to spacecraft so they know where to go what to do and what information to collect each complex of the deep space network has a 120 degree field of view to achieve full coverage NASA built the first station in California's Mojave Desert the second station in Madrid and a third near Canberra in Australia once a mission travels more than 30 000 kilometers from Earth it is always in view of at least one of the stations I describe it as being air traffic control for the solar system or the postal service for the universe [Music] the three main telescopes were expanded to better hear Voyager 2's Neptune encounter when it arrived two years later Voyager revealed at least four rings of ice and rock it also discovered the Great Dark Spot on the planet's southern hemisphere a raging transient hurricane the size of the Earth the winds on Neptune can reach speeds of over 2 000 kilometers an hour the fastest in the solar system on Route Engineers altered Voyager 2's trajectory so it could study the largest of Neptune's moons Triton a world with a thin atmosphere with geysers spraying out dark material not water ice as we'd experienced some of the inner moons of the other giant planets but dark material that that thin atmosphere and winds were carrying across the surface creating dark streaks on the surface of the Moon [Music] days later it snapped a final photo neither Uranus or Neptune have been visited since the ice giants Uranus and Neptune were all but points of light to astronomers until the flyby mission of Voyager 2. we started to realize Uranus and Neptune are very different than Jupiter and very different than Saturn we kind of had this view pre these missions that the four gas giants were all the same we saw worlds that had some of the coldest temperatures ever recorded with some of the fastest winds ever moving where the energy for such Dynamic systems is still a bit uncertain we've been sending deep space probes out for decades now but there's these two planets that we know only from the visit of Voyager 2. we really know very little about these planets and it's very much overdue I think that we send back another probe and have another look we might have a reason to go back but we have so many places to explore beyond Earth in our solar system where do we go if there's just too much to do beyond our outermost Planet lies a mysterious realm of small rocky worlds that the Voyages would merely pass through but they were not forgotten four and a half billion kilometers beyond our Earth lies a realm of icy bodies the remnants of our Solar System's formation the Kuiper belt is a huge region of the edge of our solar system where the Comets live so it's a very very mysterious region despite its massive size the Kuiper belt wasn't discovered until 1992. within it Liza World once called a planet Pluto discovered by 24 year old Clyde tomboy in 1930. Pluto was reclassified as a dwarf planet in 2006. following the discovery of several other objects in the Kuiper belt that were similar in size [Music] however that has not detracted from our desire to unlock its Secrets the New Horizons probe was developed to expand voyager's grand tour of our solar system the New Horizon spacecraft was able to go where the voyagers couldn't go they couldn't encounter that final traditional world of our solar system Pluto the probe embarked from Cape Canaveral on January 19 2006. there were so many unknowns about Pluto how it was formed what it would look like thank you at a distance of nearly 5 billion kilometers it would take over four hours to send and receive radio signals from the probe download speed from New Horizons was only one kilobit per second 50 times slower than the dial-up modems of the 1990s it took 15 months for all of the information it gathered to return to Earth everybody was waking up in the morning ready to download all the latest images that had come in and been processed and were all being put up online it's just amazing what this meant to all the people that worked on it but it also meant a lot to people around the world [Music] until New Horizons scientists weren't even sure if the dwarf planet's actual size they were able to conclude that Pluto is 2376 kilometers in diameter the largest of the cataloged dwarf planets but it was the features on its surface that were truly astounding a world with nitrogen ice glaciers flowing across its surface into valleys underneath mountains that were three kilometers high made from water ice covered in a nitrogen snow the textures and the patterns make it look a bit like an artwork in places surprised Us by revealing an extraordinary heart-shaped region for very smooth landscape it's a new Surface but by new I mean within perhaps a million years certainly not the ancient crater surface that everybody expected to see as New Horizons departed Pluto it revealed a naturally blue sky created by nitrogen gas just like on Earth Sun shining behind Pluto lighting up that blue atmosphere and the Blackness of deep space that we're traveling out into leaving behind the worlds of our solar system head into the interstellar void [Music] observations of the outer solar system continue to raise as many questions as answers indeed a number of objects Beyond Pluto follow unusual orbits orbits that could hint at an unseen gravitational force another planet currently dumped planet nine if we look at the other objects in the very outer solar system some of the asteroids the rocks that are floating out there they seem to be pulled a little bit off Target these orbits all seem to line up pretty well in One Direction and that tends not to happen by chance they could possibly be a very massive Planet out there that we haven't yet discovered planet nine for it to be there and for it to be having the effect that it is it has to be pretty big somewhere between Earth and Neptune what we call a super Earth which is interesting because super Earths are very common around planets around other stars so one of the most common types of planets and all the other star systems just happens to be the one we're missing mathematical modeling and computer simulations hint at Planet 9's existence but it has yet to be observed directly now neptune-sized objects will be quite big and you might expect that we would see that pretty easily except that this could be 20 times as far away as Neptune is the lights that we see from the planets is reflected from the Sun and if there is a ninth planet it would be so far away from the Sun that the light would be incredibly faint the problem is that the most likely direction that we think this thing might be in this hypothetical planet nine is actually slap bang in the middle of the Milky Way the most dense part of the sky as far as how many stars there are how do you separate what could be a planet a dim reflecting object in the night sky from the many other background Stars well it moves relative to these background Stars which to our telescopes essentially appear fixed as it would take Planet 9 between 10 000 and 20 000 years to orbit the sun it could remain a distant mystery for years to come we're looking for a needle and a haystack for the needle looks like hey that's why planet nine hasn't been found yet if it is there the Voyages are now the furthest objects forged by Humanity and as such they've given us the most distant photograph of our home on February 14 1990 it took a final image turning its cameras back to the inner solar system and taking a panorama a family portrait if you will of the entire solar system and within one of the beams of sunlight a tiny pale blue dot the Earth seen from the perspective of deep space I think it made everyone stop and wonder a little bit just about how large the universe is in our place in it in some ways voyages 1 and 2 have both already entered Interstellar space I used to define the edge of the solar system one is to say where does the influence of the sun end and that would be called the heliosphere both voyages have passed that Last Remnant of our own solar system and continue into our larger Galaxy they have fuel that will probably mean that they can send signals back until maybe the mid-2030s it's quite amazing that something launched back in the 70s could still be talking to us so far into the future the Voyager probes carry with them a history of humanity as space-faring explorers and the promise of future discoveries it's the serendipitous discoveries as you go further and further into unknown territory which we look back on and say huh didn't expect to see that the depths of space called and Humanity answered the Voyager spacecraft fundamentally changed our idea of what the outer solar system was like and showed us new worlds that beckoned to be explored our missions to the outer solar system have provided nearly half a century of Milestones you really felt part of it every decade of your life you saw something new about our own solar system it was completely inspirational [Music] each robotic surveyor has opened up the possibilities of future missions if we can actually go to Enceladus in the future I think that will be an absolute Watershed for our understanding of whether life could potentially exist in our solar system these distant Travelers are a monument to human exploration it makes all of the solar system and beyond a human place because that's how far we've gone [Music]

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Keywords: Spark, Science, Technology, Engineering, Learning, How To, education, documentary, factual, mind blown, construction, building, full documentary, space documentary, bbc documentary, Science documentary, NASA, planets, jupiter, saturn, uranus, neptune, io, jupiter moons, saturn moons

Id: ETAzIPfbjtU

Length: 52min 0sec (3120 seconds)

Published: Wed May 03 2023