When Mars Was Like Earth: Five Years of Exploration with the Curiosity Rover

[Music] good evening everyone my name is Andrew frack no I'm the emeritus professor of astronomy here at Foothill College in Los Altos Hills and it's a great pleasure for me to welcome everyone here in the Smithwick theater and everyone watching us on the web to this program in the eighteenth year of the Silicon Valley astronomy lectures these lectures free of charge for everyone here locally are made possible through the support of for organizations that do public outreach in science the Ames Research Center of NASA NASA's one of NASA's premier centers in the country NASA Ames and the Foothill College astronomy program which offers day and evening classes in astronomy the venerable Astronomical Society of the Pacific an outreach organization in astronomy and the SETI search for extraterrestrial intelligence SETI Institute in Mountain View we're very grateful for their support today's program is what I'm especially looking forward to we're very lucky to have with us dr. Ashwin Vasavada he is a planetary scientist at the NASA Jet Propulsion Laboratory in Pasadena California and we're very grateful to JPL for making him available to our program his research interests include the climate history of Mars the weather on Jupiter and Saturn and boy is there weather on Jupiter and Saturn the possibility of ice at the poles of the moon and on Mercury currently he is the project scientist for NASA's Curiosity rover that began development in 2003 and successfully reached Mars in August 2012 sending back amazing images and data about the red planet he now leads the international team of scientists as they explore Gale Crater on the Martian surface we are very very fortunate to have him with us today so let me present to you dr. ash la subida talking about when Mars was like earth five years exploring with the curiosity Mars rover alright good evening everybody it is wonderful to be here and thank you so much for spending the evening learning about Mars and the Curiosity rover and everything we've been able to do over the past five years as mentioned I'm from the NASA Jet Propulsion Laboratory it's also one of the premier NASA centers NASA Ames we love NASA Ames too we're sort of the sister organization but down in Southern California Pasadena JPL is the NASA center that's mostly known for things that go out beyond the moon so Voyager for example Cassini those distant deep space missions historically have been done through JPL now a lot of us other NASA senators do those too but that's sort of what we were known for the curiosity mission itself started as was mentioned in 2003 I've been on it pretty much the whole time it's been basically my career more or less because it's been about 15 years that I've been involved in it and it's been five years on Mars but the previous time before that was all in the design and the development and the testing and will show some of that but we'll mostly talked tonight about what we've been discovering on Mars itself so there's the rover it's a car-sized Rover it's big biggest moving robotic vehicle and one of the most complex spacecraft that nASA has ever sent into space and it also can take selfies as that was a special bonus and yeah no one was there to take this picture in fact we put on a camera on the end of the rover's arm in order to do scientific analyses of the soil and rocks on Mars and one of the engineers realized that when you design a camera on the end of an arm that can focus at any focal length you can actually turn it around and take pictures of their over and it wasn't as easy as it sounds because we have a very narrow angle camera to look at the little spots on the ground and so it actually takes about 55 pictures and 55 different motions of the robotic arm to take this selfie but it was worth it and now we take a selfie every few months just to see how the rover's doing how much dirts on the deck and that sort of thing and these are always some of our most popular images so we've been exploring Gale Crater it's a crater on Mars for about five years the rover was designed and tested to last two earth years so that's the warranty the warranty expired about three years ago now but it's still going because when NASA builds something the last two years you know guaranteeing to the taxpayers it's going to last two years we they tend to last a little longer than that because we try to build them to you know to pretty high standards so we're very fortunate that it's still going it has probably a few years left still it's one thing you'll notice is there's no solar panels on it it's the first Mars rover it's it's a third-generation Mars rover but the first to use a nuclear power source so the back end of the rover on this image is a canister that has cutonium in it naturally radioactive material gives off heat that heats turned into electricity that charges the battery so the rover they kind of like your cell phone you have to charge it up overnight charge a battery and then during the day we run down that battery and then overnight that plutonium slowly charges the battery back up that way we don't have to worry about dust collecting on solar panels but the downside is if you do outlet outlet live year warranty the plutonium does decay over time and so if nothing mechanically breaks the mission will end when that plutonium power source no longer can charge the battery enough to keep operating the rover but that still a ways off so we're still in good days with curiosity one final note about me I grew up in Stockton so I I'm sort of a northern California person for the early part of my life at least now LA after 20-some years finally getting used to it but one of the reasons I was happy to come do this lecture is because I still feel like in Northern California and deep down somewhere inside and also because my my high school calculus teacher is here so okay so a little bit about Mars for those who don't know a lot about it this is the relative size of Mars next to Earth but they're a little further apart in real life so here's earth one thing you'll notice immediately is the lack of a nice blue ocean on Mars today Mars is a very cold and dry place it very uninhabitable to life very thin atmosphere radiation gets down to the surface that would destroy most organic molecules that would be involved in anything living so pretty unfriendly today but we think that was quite different in the past but even today you can see that there's little hints of water there these are actual clouds so Mars has a very thin atmosphere about 1% or so of the Earth's atmosphere but it also has a trace amount of water vapor that can form clouds in the winter and also has some pretty thick polar caps in fact these polar caps are huge if they've melted Mars would be covered by maybe 30 feet of water everywhere so it's a not insignificant amount of water it's just not liquid and life as we know it anyway you really need water in the liquid form so that's what it is today but keep your eye on Mars for a second maybe it was like that three or four billion years ago this is probably the optimistic view in the sense that here's whole ocean with a thick atmosphere and weather you know hurricanes going across the ocean maybe reality is somewhere in between where we have a lot of evidence now that early Mars have lakes and rivers maybe even an ocean like this here's some of that evidence why do we study Mars in particular why do we get excited about the prospects of life on Mars it's pictures like this there's a long history of being fascinated with Mars partly because it's one of the closer planets so people no one had to discover it in a telescope it's it's a red dot that as far as human history goes people have been looking at it in the sky but when we did start looking at what telescopes there was all sorts of crazy ideas about canals on the surface or civilizations that sort of thing and when we finally got there in the 1960s and 70s and got these first pictures there was a lot of churn there too because the first pictures looked very barren like the moon and disappointed a lot of people but one of the very next missions return images like this where those lunar like craters in between those craters all of a sudden you saw channels like this that looked very much like river systems on earth and that's still to today the hypothesis is that these once were flowing rivers where rainfall or groundwater came up to the surface and collected in these lowlands between the craters and flowed you know with gravity down hill and streams connected together and formed rivers and they emptied into big basins that may be formed lakes and oceans a little later on we found that and this is all very the ancient terrain on Mars probably 3 to 4 billion years ago we found that that period of water activity that liquid water was present on Mars ended in sort of a climax where a bunch of water flooded across the surface and some of the youngest features of that are related to water are these giant flood channels so these are miles across these are the kind of thing like on earth you'd find when entire Ice Age ended and a glacier that was holding back a huge ocean of meltwater suddenly broke and and you could find channels like this in some parts of northern United States where almost like an entire inland ocean drained and scoured out the land these are the kind of things we find on Mars and some places that are slightly younger than these but still very old when we got even better spacecraft to Mars with even higher resolution cameras and big telescopes pointing down to the surface from space we found features like this this is about a mile across now and it's a River Delta so a channel came in from this side and over time the channel put some mud over here put some boat over there put some boat over there and fanned out just like the Mississippi River has a delta that it's forming underwater under the ocean where it where it goes into the Gulf of Mexico so if you were to remove the water above the outlet of the Mississippi River you'd find a Delta just like this so a lot of really incontrovertible evidence now that Mars was a very different planet three to four billion years ago and had a lot more water so here's kind of a timeline you evolved especially since Jurassic Park came out you're all familiar with Ages that we call things on Earth different periods of time that geologists use to describe ages we don't have a Jurassic on Mars that we have an O akkyun like Noah named after the time when a lot of water was on Mars we have the Hesperian age from about 3.8 billion years ago to 3 billion years ago where we don't really know if it was wet or dry but that's when some kind of major transition in the Mars climate happened and then we know from about three billion years ago to the present Mars was probably pretty similar to what it is today very cold very dry and so all that really cool evidence for lakes and rivers and Delta's exists in the nawaki and primarily but some is here in this Varian and what's kind of neat is curiosity is exploring features that we'll talk about in the rest of this talk that all date from about this time period so one of the things that we're able to study and and still hope and even find more about as the years ago by is that transition from the very wet Mars possibly warmer Mars to how it how things went bad and you got to the very cold and dry place of this today so some of the questions that we asked as a scientist as scientist who study Mars and who work on this curiosity mission are questions like this Mars was once wet but was it warm so in other words was was the atmosphere thicker and did the climate support a whole hydrological system with ocean somewhere evaporating water raining somewhere else like on earth or what were all these lakes and rivers just kind of transient events because the volcano went off somewhere and just warm the atmosphere for a hundred years that would be a lot less interesting for life because if it was more of a sustained you know billion year time that gives life a little bit more time to operate in terms of originating on Mars like it did on earth but we still are not sure if all those features couldn't just be explained by little transient one-off events you'll see though that curiosity is changing our view of that and that gets to this question was it habitable and if it was habitable for how long was it was it just habitable for a hundred years not not very interesting biologically but if it was habitable for ten million years now you're talking and so we'll talk about that I also wanted to talk a little bit about what the word habitability means in the context of our mission so curiosity doesn't go out with the goal of detecting life on Mars that's actually really hard to do even on earth you pick up a three billion year old rock on Earth and that's really the interesting time on Mars it's very difficult to prove that life is evident in that rock on earth even though we sort of know it was teeming with life back then because a little tiny microbiological organisms don't leave a lot of fossils behind they leave very faint traces of themselves and so it's pretty challenging to go to Mars and think you're gonna find evidence of life that's three billion years old but what we could more confidently do ten years ago when curiosity was designed was asked it to look for evidence of habitability habitable conditions not was life there but were the conditions on Mars able to support life what do we mean by that here's a nice you know not the perfect habitable place on earth but a very habitable place on Earth nonetheless Death Valley it's kind of ironic what makes the place habitable on earth liquid water that's sort of the common denominator for life as we know it and you know it's hard enough to search for life as we know it we don't try to search for life as we don't know it so we look for liquid water on Mars as a element of a habitable environment we look for the key chemical ingredients that life requires so it's okay if you have liquid water but if you don't have carbon you're not gonna form life as we know it you don't have nitrogen oxygen phosphorus sulfur all the things the basic building blocks at all of our cells and and machines of life in our bodies are made out of we look for those things that are present naturally on Mars as raw material for life we also look for sources of energy so energy requires of life requires energy so we make you know we're able to survive because we're at the top of the food chain and we things that eat other things and eventually gets traced back to sunlight growing plants that other things eat so we get our energy indirectly but microorganisms can get their energy from a lot of different ways they can get them from sunlight microorganisms you can find living things two miles below the ground on earth because they're able to exploit the chemicals inside rocks and eat those chemicals and draw energy from them so we can look for those sorts of chemical or other sources of energy that life would need and if we find these three things that's kind of a good agreed-upon list that you could declare you found a habitable environment so how do we go find those things you build a really cool Rover so this is a car-sized Rover it it's a third generation as I mentioned the first one was kind of the size of a shoebox that was in 1997 called Sojourner and that was the first demonstration of being able to drive robotically on another planet and then followed those in 2003-2004 with - a twin set of Rovers called Spirit and Opportunity and opportunities still going today way outlived its warranty we're hoping to do as well but it's been going now for 14 years and 5000 Martian days and now the that's about a size of a golf cart and then you got to curiosity because we have a set of instruments and capabilities that required this big Rover and namely it's of course we want to drive around like like the other two Rovers did but the key thing that we do differently from any rover that's gone to Mars before is drill into rocks so we have this six-foot robotic arm and we have at the end of that robotic arm a drill and the reason we have that drill is because in order to figure out if those key chemical ingredients for life are there in order to understand how much water was there and what it did to the rocks you actually have to sample that material and put it into laboratories and run laboratory experiments to do the quality of science that we want to do so the rover is this big for two reasons has to house this big jackhammer drill and it has to have a whole front end dedicated to these laboratories so the rover was built around the capability to drill get material powder that you create with the drill drop it into some laboratories on the rover itself and run these experiments so we're doing some pretty sophisticated stuff with this Rover and that's a lot of what led to its size and its complexity because you have to design a drill that can work dozens of time without ever being able to clean it lubricate it anything you got to run chemistry experiments without ever being able again to to clean something or unclog something or all those things you would easily do in a laboratory on earth take something apart clean it put it back together you can't do that so a lot of the the engineering challenge from the for the science of this Rover was to design those systems that can operate 100 million miles away for as many years as we can and do many experiments without ever having a human being able to service it we also have a whole bunch of other instruments I won't go through all of them but we have cameras that of course look around and take all of our pictures another camera on the end of the arm we have the drill I mentioned the laboratories in the front of the rover we have a weather station we try to get as much as we can out of these missions by putting a whole bunch of different sensors and experiments on them one of the coolest things we have though is its laser so we if we see anything living on Mars we can kill it kidding of course so we have this laser this is a really neat instrument because it we can actually vaporize little bits of rock and soil on the surface of Mars and those sparks we can observe with our cameras and we can look at the color of the spark in particular so this is like a classic high school experiment you put some substance in a flame and see what color turns and that tells you what is inside with it what it's made out of chemically so by shooting with this laser and creating a little spark a bit of plasma we can image that with a spectrometer look at the wavelengths of light that are emitted and actually figure out from up to 20 feet away what a rock or soil is made out of that helps us because then we don't have to go drill every little thing that we find so instead we're able to do this remotely and then if something really stands out we can drive up to it and put the arm on it check it out and if it's really exciting but then we think of drilling it and sampling here's what it looked like when we were making it I'm a scientist of course so they don't let me anywhere near it these are all the engineers who built it who just are you know complete magicians at what they do and they were able to you know design and build all this and then it was integrated it was fabricated you know and put together in a cleanroom because we're actually doing some very sensitive chemical experiments in those rock samples so even you know the grease from a fingerprint would throw off our measurements if we're trying to look for organic molecules so the entire Curiosity rover has never seen a human fingerprint it's all been assembled with these in a cleanroom environment with the everybody wearing bunny suits and and keeping it as clean as we possibly can this is actually the day that it drove its first it's it took its first steps so speak so you know here's sort of where it lives now kind of a lonely place but this is a little introduction to where we ended up we had to choose somewhere to go with this Rover that we could conduct these experiments so that's another big challenge for the science team in addition to designing all these experiments and figuring out how to answer the questions about habitability another unique thing is that Mars you know is about it's like if you took all the continents on earth and put them together that's about the same area that Mars has on its surface so you know where would you go if you had one chance to answer an important question about Earth where would you send your one Rover that could Rove you know ten miles or so yeah it who knows right and it's a it's a tough question took us about six years to answer so we scoured the surface of Mars using all the satellite data that we've been able to accumulate from the orbiters that are at Mars like this one and had a lot of contentious meetings where we brought scientists together and everybody threw out their ideas and other people said wrong and you know that's about what we did for six years until we narrowed it down from 60 landing sites to 30 to 10 and we had a big meeting where we got to four and then we went to four from four to one on a very momentous day about a year before launch and we ended up with this site called Gale Crater right here and one thing you can see that's even from this picture that's a little bit unique about Gale is that it's not empty it's got a mountain in the middle of it and that mountain is what drew us to it so here's Gale Crater it's about 100 miles across and it's a three mile deep hole in the ground on Mars and craters like this are formed like they are on the moon where a giant asteroid or meteor hits the planet huge explosion and dirts ejected out and then you're left with this empty crater so they shouldn't have a mountain like this in it sometimes they have a little peak in the middle like this that's probably their from the original impact but all this stuff got here later and what we were able to see when we looked with the orbiters at Gale Crater is that this is a mountain of layered rock which is also telling us that it's not a volcano it didn't form with the original impact layers of rock built up over time and filled this crater and that immediately got us thinking that you know that you could either do that from wind or you could do that from water and some of the layers were or we could even tell this from orbit some of the layers were made out of minerals that form when Martian rock interacts with water specifically things like clay minerals clay minerals formed when volcanic rock interacts with water over some period of time it gets weather down into a clay and we see some of that in this mountain so two things attracted us one the evidence that there was water involved in whatever process brought these there's this sediment into the crater to that there was a three-mile high stack of layers and to a geologist that's really wonderful because it means that a lot of time has been recorded in that stack you don't build up three miles of sediment overnight so just like if you were to go to the Grand Canyon and start at the bottom and work your way up you'd walk through millions and millions of years of Earth's history our hope was we go to Gale Crater we land at the bottom we drive up we can walk through we can drive through millions of years millions of years of Mars history so we don't only have one chance to ask the question about habitability on Mars we have a chance to ask it over millions and millions of years of Mars history to see if different periods were habitable if it went from habitable to inhabitable all those kinds of questions so that's why we chose it the next thing I'm going to show you is a movie which is does a better job than me just talking about it showing you some of the steps involved in building the road or testing the rover and getting it to Mars and it won't spend a lot of time on this because I want to talk about all the science we discovered but the way it arrived at Mars and how we how the engineers designed a landing system for a one-ton Rover is practically worth the price of admission itself it ate up and watched the landing five years ago I figured some of you did I certainly did and you know those of you saw it know that it just was you look at this system that landed the rover you think that's crazy and that's what NASA thought too when the JPL engineers first proposed it basically landed with a jetpack flying down the rover to Mars and landing the road were on its own wheels on the Martian surface so unlike the other systems before where you land a rocket ship or you airbags were equally crazy in their day but this is even another system so here's that movie you [Music] that great things take many people working together to make them happen is one of the fantastic things of human existence you not only we've driven the rover we've removed its arm put it's all through its paces but it's been in a thermal vacuum chamber and kept very cold it parts of it have been a centrifuge we've done drop tests pull tests drive tests load tests dress tests just amazing amount of testing this vehicle have gone through we've tried every way of operating at the vehicle using the software literally thousands and thousands of hours of software testing it's been just a an amazing several years really a constant testing and development finding problems fixing those problems and going on to the next problem I think she's ready to go see this is the LD on channel one now see you have permission to launch Roger you're sitting with account you - ten nine eight [Applause] [Music] am i confident that she's going to go and she's going to be successful absolutely it's gonna go and she'll be good boy you're on detailed steps has separated we work on the ground commands standing by for backshell separation we are in powered flight we're an altitude of 1 kilometer descending standing by prospective sky crane it started shopping for mercy [Applause] [Applause] but the fantastic demonstration of what our nation and our agency can do I could only think of the words of Teddy Roosevelt as I was sitting there it is far better to their mighty things even so we might fail then to stay in the Twilight that knows neither victory nor defeat and the team brought us victory today today right now the wheels of curiosity have begun to blaze the trail for human footprints on Mars this is an amazing achievement well today on Mars history was made on earth the successful landing of curiosity marks what is really an unprecedented technological tour de force it will stand as an American point of pride far into the future we've got a long mission ahead of us and and because of that and the capabilities Rover we have as possibility for just monumental science accomplishment within two months the team found an ancient riverbed evidence of flowing water we have found a habitable environment that is so benign and supportive of life that probably if this water was around and you had been on the planet you would have been able to drink it right that never gets old yeah so at the landing you know you're you're kind of stuck because Mars is about 15 minutes away by the speed of light so there's nothing you can do though all those people that were there looking nervous while I was lying they weren't flying anything they were just watching their screens as data was coming in 15 minutes after everything actually happened that's just the nature of landing something on Mars so everything they did they had worked for years to program curiosity to fly itself down safely and and we were all just sort of helpless that night and it was all kind of through computer screens you know so as emotional as that night was and it was very emotional the thing that is even more experience for me was the launch because you're there in Florida you you know your chest I shouldn't do that it's very realistic your chest is something with you know with the Rockets vibrations and you know that you've just spent like you know six seven years building this really delicate complex machine and you viscerally are like watching it blast often this controlled explosion into space and not only is it just terrifying but you really get this sense that you're you're sending something you know away from Earth when you see a rocket launch you know with your own eyes so go do that sometimes there's a lot of good launches these days including from from Vandenberg down down in Southern California so we landed and one of the things that we were able to find almost immediately was thanks to this crazy landing system so these Rockets were firing from the jet pack and even though the the that jet pack stayed something like 40 feet off the ground the the Jets created little areas that scoured away the local sand and gravel and exposed bedrock below which was pretty cool because if you're a geologist you don't really like sand and gravel you don't know what it is or where it came from you like bedrock bedrock means that rock was there it mean it it formed there and tells you something about it and so the fact that we landed on this big gravelly area but within these scours we had rock of course the very first thing we did was go check out those areas and and they actually was kind of a goldmine you you heard this alluded to at the end of that video there was a couple spoilers in there and what we found the first year but what we found was these slabs of bedrock that were that were some places buried underneath the soil were eroding and as they were eroding we realized the slabs were made out of a bunch of little rocks cemented together and those little rocks were falling out in collections this is probably a billion years of erosion and the rocks themselves were rounded and rocks don't really get rounded through many natural processes other than the most effective one on earth is is transport in the stream like pebbles just rotating and colliding with one another in a stream bed you can you can get you know we measured all the angles of the rocks exactly how rounded they were the size of the rocks compared them to different places on earth and it really it told us that we were actually driving through an ancient streambed on Mars that probably had transported these pebbles for something like ten to fifteen miles and the water was flowing somewhere between sort of ankle-deep to hip-deep so it's a pretty good sized stream maybe even a river and you know for for people who had who had seen for maybe a couple decades like me rivers on pictures of Mars from from orbit you sort of know that these things exist but when you're there and you're seeing the rounded pebbles and you think you know man we were driving right through an ancient streambed that's that just brings a whole new meaning to it and so this is the first time we really were able to find this evidence of that water flowed on the surface of Mars in a pre vigorous way we went to a place where that water may have collected into a lake and our apophysis was at this flat area here you can see how different it is now the gravel is all gone it's just a flat plain of rock that very much looks like it could be an ancient dry lake bed and so we drilled into it this is the first time we've got out the drill here we are drilling in a place we called Yellowknife Bay and here's what it looks like when we drill we end up with a little dime sized drill hole and and if you can see the these little black dots here those are the laser places we blasted with the laser so we're looking down with curiosity from about seven feet off the ground firing our laser into a dime sized drill hole and making that little pattern down the side so it's a pretty fantastic machine and with the laser we could we could then see if the composition of the rock changed as we drilled about two and a half centimeter I'm sorry about six and a half centimeters about two inches into the surface to gather the powder what's cool about this picture is that we drilled the rock and then we took this picture at night using our own LEDs our own lights at the end of the arm in the middle of the night and what's neat about that is that Mars is very dusty so any picture you take during the day always has its orange cast to it because you're the sunlight is very heavily filtered it's like a very smoggy day on earth but if you wake up in the middle of night and take a picture with your own lights you actually can see what color Mars is for the first time so this is like a true color picture of Mars and it's you know surprise it's orange it's a it's just not as orange as it looks in the middle of the day and and what's really cool is that the powder that we drilled is not orange it's gray and so the the skin of Mars is all axud eyes Dan dressed adrylek and you can get more pristine material which is a very good sign for one day finding evidence of life because it means that the environment that's now changing Mars today hasn't penetrated that deep into the rocks where things could have been living at one point and it would have you know it could have destroyed all that evidence through the oxidation that's occurring at the surface so what did we find here's a couple of pictures that show you the kind of data that we get we drill into the rock and we put it in the material into some laboratories and one of the laboratories takes an x-ray and shines that x-ray through the rock powder it's called an x-ray diffractometer diffraction is a is a fancy scientific word for splitting light into different wavelengths like creating a rainbow and you shine light through a prism we do that just with x-rays and the reason that you get these rainbow arcs when you shine x-rays through rocks is that the rocks are made out of crystalline minerals so every mineral is a kind of crystal that diffracts the x-rays at in a different way and so a scientist can read these arcs like a fingerprint at the spacing of the arcs the intensity of the arcs and tell you exactly what minerals are in those rocks and if we find clay minerals like we did these this big arc down here is called phyllosilicate that's a kind of that means basically a clay and so we found clay minerals in this hypothesized lakebed which tells us that water was actually here and it actually probably was a lake bed the other experiment that we have other laboratory we have is is a gas chromatograph mass spectrometer which means it's a very common instrument you'd see on all the detective TV shows it's a kind of thing that tells you element by element what's in a sample and the way we get the material out into the instrument is you put the powder in the laboratory and you bake it and you bake it at about a thousand degrees and as you do that the rock starts to degrade and as the rock degrades as you're slowly ramping up the temperature different minerals decompose at different times and so you can this time is running left to right and so a bunch of water comes off first because water is pretty easily removed when you heat something and then as you heat it up more and more carbon dioxide comes off oxygen comes off other things come off and you can you can sort of reconstruct what was in the rock based on how it degraded as you heated it and so these two pieces of information are sort of the core science we get from any rock sample and they work in synergy with each other we can detect clays both by the arcs that makes and by the fact that clays decompose at about 600 degrees and they release a bunch of water so we also found carbon oxygen hydrogen sulfur phosphorus nitrogen all those things I we talked about earlier being important for all the cells and living organisms we found evidence of liquid water and we found sources of energy because they were different one example is there's different types of sulfur in here which have different chemical States for those of you are chemists there's reduced sulfur and oxidized sulfur minerals and that's the kind of thing that a microbe can use to draw chemical energy from so even at this very first site in the first year of the mission we found water evidence of water we found key chemical ingredients that life would require we found sources of energy so we found a habitable environment which was fantastic so that took a lot of pressure off of us frankly because we were able to to tell all the people who you know supervise us that we were able to successfully accomplish the goals of the mission in the first year we were on Mars at this first drill area and that allowed us then the last four years to just add to that story more and more knowing that we at least accomplished the basic elements of what we set out to do so we the the reason that's a little significant too is because we weren't planning to spend much time at around where we landed we told our bosses in Washington DC is headquarters you know do spend a couple weeks there then we'll go to the mountain pretty quickly after that we spent about a year at this site because we discovered all this great stuff and so we kept saying oh just wait just wait but then we did finally pick up stay I remember that it turned out it was July 4th of 2013 we landed in August 5th 2012 so almost a year after we landed we finally left this area after accomplishing all this and made a beeline for the mountain and along the way we found this spectacular rock formation a bunch of sandstone that was all big slabs of sandstone they were all tilted in one direction and the direction they were tilting was facing the mountain itself so as we were driving to the mountain we came across these and there was more than one of these formations and we studied it and based on the evidence of finding the river before and the lake and studying the sand up close and figuring out the sand particles were too big to have been transported by wind must have been involved with being transported by water we concluded that this formation was a delta so here's a little cartoon of what we think was happening water is flowing here from right to left and you have water flowing downhill and some rivers then that water encounters the lake and when do you encounter the lake that fast-moving river water all of a sudden slows down so all the sand it's carrying and all the dirt it's carrying begins to fall out of the water and so you end up with all these sand deposits tilted sand deposits right where the river meets the lake and then as you go further into the lake and now all the silt begins to fall out and you get these very fine layers of of silt that build up at the bottom that muddy stuff your feet get at the bottom of the lake is over here so here's where you get your pebbles here's where you get your sand and here's where you get your mud so we found the pebbles in the river we drove a little bit closer to the mountain we found the tilted beds of sand then of course our hypothesis was when we get closer to the mountain we're gonna find the lakes more lakes not the lake that we found out on the plains but if the deltas are all facing the mountain maybe the mountain itself is made up of Lake deposits as funny as that sounds and we got to the mountain and I hope you can see this but what you're looking at our slabs of rock this is this is only about two inches across here and the rocks are made up of extremely fine layers just hundreds and hundreds of layers about a millimeter thick each and the entire mountain is is that we've driven up so far as made of just continuous set of these millimeter layers now we've driven up about like a thousand vertical feet that are made up of these tiny layers and without much of a break in that continuity of the layers and and when you have these very continuous layers of muddy of mud sized sediment it's very consistent with the idea that this is all mud that formed maybe annually as Lakes were fed by streams and then hardened into rock so how do you get a mountain where there once was supposed to be a bunch of lakes good question so here's our idea is that Gale Crater formed and then back when Mars was a little more wet and there was maybe precipitation or at least groundwater groundwater flowed through all the cracks in the rock and maybe fell out of the clouds and formed lakes that filled up the crater and the lakes maybe never were that deep but they were but sediment continually is being brought in by the rivers and that silt just settled out in these lakes and slowly over many many millions of years built up millimeter by millimeter and the rake the lake rose as the the mud kept getting thicker and then over time so imagine like keep your eye maybe on this spot where imagine the rover is studying right there over time what happened is that a few things so the lake level was at one point here and then it got higher and higher and at some point this stuff that is not really lake is just maybe dust filled it up even more and then the climate of Mars changed in a way we're no longer were things being brought into the crater but now wind was scouring scouring stuff out of the crater and it's scoured it out in a way that sort of dug this big pit into what was a full crater at one point leaving the sand this dusty stuff here and then the layers of lake sediments that we were now studying climbing up this way so these lake sediments would have gone all the way across when the lake was filling it but this all this has been removed over eons by wind so that's our story and we're sticking to it and we're continually finding evidence to support it and making our case to the rest of the sides of the community through the usual process lots of peer-reviewed papers but so far when we run these ideas by earth geologists who of course can do a lot more advanced stuff than we can do on Mars they you know they think we have a pretty good idea of what we're we're seeing here so we've now driven about 18 kilometers so you know 11 12 miles on the ground we landed out here on the plains this is a sort of map looking down these are the plains we landed in this is the mountain and all the layers of the mountain so we landed out here we made all those discoveries right where we landed at Yellowknife Bay then we drove pretty fast found those deltas kind of in here we got to the edge of the mountain about two years into the mission and for the last three years we've been slowly going up all the layers of the mountain little by little and we're here right now and we'd like to do this remaining segment before the mission ends so hopefully we'll be able to do all this in the next two or three years and once we get up to this layer we will have studied all the layers on the mountain that appear to have formed through water so far we've drilled about 15 holes here's 12 of them and you can see there's kind of a variety there's holes that that the material is reddish once when we drill it so maybe the oxidation has has penetrated into the rock there's holes that are most of them are pretty great and in those grey holes is where we tend to find the clay minerals and even organic molecules very simple carbon containing molecules that have survived because they haven't been oxidized and destroyed and then we found a couple more red holes lately I think the next few slides is a little bit more of a tour just my favorite pictures so but just to give you another sense of the variety of things that we're seeing as we've been driving along the last few years here's here is a nice picture showing three materials that we've gotten very used to seeing that are very different from each other there's the first thing you see here is this pale bedrock that's very smooth those are the lake deposits and when we look up close at these there they have those millimeter scale layers that tell us they were like deposits above them in this area there this there's this very rugged sandstone and this is rock that was once loose and that's now cemented together this particular sandstone is very much consistent with being driven by wind as opposed to those Delta's that were water this is an ancient dune field sand dunes that were there two three billion years ago that have now turned into solid rock and then the third thing you see here is modern sand so this is just sand that's blowing around today and so you know when we're driving around we have to sort of mentally ignore the modern stuff it's not that interesting we have to find the places where the lake deposits are exposed at the surface so we can go study them and then we have to understand how this later stuff covered up some of the lake deposits and and how it's related in timing this is one of my favorite pictures these are the Murray buttes these are several stories high these big beauty drove through it's like you're driving through Utah or somewhere Bugs Bunny and roadrunner country and you're driving through here these are those lake deposits and again the sandstone is above them and the reason you get these beauty about New Mexico Utah or Mars is because the sandstone is a little bit more resistant to erosion so even though most of its gone these layers used to connect at one point the the sandstone is a little bit of armor that's keeping that's protecting the rest of the stuff from being eroded away so you get these little towers but eventually another billionaires these will be gone too leaving these these like deposits exposed here's the thing we saw at the at the beginning the Selphy what's neat about this is we studied some of these modern sand dunes it was actually the first time we've ever seen modern sand blowing around on Mars the other Rovers have seen ancient dune fields but we're actually able to drive up to dune fields and watch them actually moving which was really cool too even though it has really nothing to do with life and our main goals in the mission we're on Mars you got to study it and so we we did some playing around we dug some trenches we watched sand avalanche we watch sand blow and one of the things we discovered was that not surprisingly there's a lot of similarities to sand dunes on earth the dunes have similar shapes because the physics is roughly the same even you have a thinner atmosphere and a little less gravity but one thing that you do not find on earth are these ripples you find these small ripples you can see those here you go to Death Valley you'll see dunes covered by these small ripples that are maybe a few inches apart you what you won't find are this other set of ripples that are about three feet apart and what it turns out that those only form in the thin atmosphere of Mars the totally different physics comes into play with the thin atmosphere in this case and so you you you really are on Mars when you see those which is kind of neat this is just showing you some results from our weather station what's plotted here this is temperature in Celsius and Fahrenheit can't really read it but I think this is minus 120 over here and something 100 Fahrenheit over here so this is Los Angeles over two years and the Los Angeles nice and warm and actually doesn't vary a whole lot from day to night and this is Mars to give you the idea of what the rover has to put up with every day so Mars varies from summer to winter like this but the day/night differences are even bigger than the summer winter differences so every single day now for 2000 days on Mars and 5000 days for opportunity the other over you have these very sensitive electronics moving parts you know all this kind of stuff that has to survive these 100 degree plus temperature changes from day to night there's you know you leave your laptop out overnight in LA and it wouldn't survive the next morning so it's yet another way that the the engineers just have to really do some amazing work to make these machines last in this really horrible extreme environment on Mars we found a meteor we aren't actually we actually are not the first rover to find these it's not uncommon actually to drive across Mars and find meteors and this is a big chunk of iron we can and shoot it with our laser and we determined that actually was an iron nickel meteorite which similar to iron meteorites you'd find on earth so that's kind of neat here's a picture of a rock slab this is about one inch here where we we see all those thin layers that are similar to what you'd find in the lake bed that we think are indicative of a like ancient lake bed but within this particular slab they're all these little pimples on it and when we looked close up in those little bumps they they have these interesting shapes and those shapes are very similar what we find if you dug below an ancient lake on earth or even a current like on earth where gypsum or other salts are crystallizing in the mud below the lake and so we found these little Swallowtail shapes that are very diagnostic of gypsum crystals which is a kind of salt that forms in lake beds as they dry up and these salts were still performing in the in the sediment so yet another circumstantial piece of evidence that we are actually studying ancient lakes on the opposite of the spectrum this is rare but it's neat to like see the whole picture we found places where the lakes clearly disappeared so this is a slab of rock that's made out of that same mud stone that formed through lakes so was once soaking wet mud that hardened into rock but unlike the other ones that sort of hardened underground over time this one hardened at the surface something happened where the lake shrunk maybe or that it got warmer for you know a few days or a few years and the top layer of mud on this particular slab cracked just the same way you'd find mud cracks in a drying pond or something on earth so it was really neat to be able to like see these cracks measure all them could compare all their angles to mud cracks on earth and figure out that these mud cracks probably formed in a single day on Mars you know so it's kind of cool to think you know that what we're seeing here one day there was a lake the lake receded for whatever reason and in one day the mud cracked and then it got buried kind of like you know the the mosquitoes in a Jurassic Park yeah if the right conditions happen you just burry it quickly and you preserve it and three billion years later we can study it this this shows some cracks in the ground that are filled with this white these white minerals and this is also a pretty common thing you could find on earth where the rock that forms most of what you see here in this case the lake sediments was buried underground hardened then cracked and then groundwater circulated through those rocks and the groundwater had a bunch of chemicals dissolved in it that then precipitated out on the on the walls of the cracks and filled them with minerals and this is calcium sulfate gypsum or other types of calcium sulfate form these form these ridges which basically are just the mineral formed in ancient cracks and now as the whole rock is eroding the crack forming thing is kind of sticking out of the surface so what's neat about this is it tells us that not only were Lakes there for a long long time we think millions or tens of millions of years to get the thousand feet of lake deposits but after the lakes were long gone and that mud hardened into Rock and fractured underground then ground water was still circulating through them still maintaining a habitable environment for some you know much longer period after that to allow all these minerals to form so not only was Mars habitable for the lakes but even a era after the lakes when there was groundwater so starting to wrap things up here Mars was once wet was it warm we think it probably was it's still we don't still have like this the smoking gun evidence for that but when you start talking about lakes that survived for millions to tens of millions of years you probably do need something like a full weather system that can evaporate water from a lake or an ocean somewhere and then have clouds in the atmosphere that bring it down and precipitate and recharge these streams that kept the lakes going for millions of tens of millions of years just your your errant volcano going off won't provide the continuity that we see at Gale Crater so we really do think the ancient climate was noted notably different and sustained in that different way so those are the answers we think I want to end well a couple more things this picture came down today and if any of you were following the mission you know why already this is very important but if you're not I'll tell you so we we had a really disappointing event about a year ago where our drill stopped working and you know that yeah I did pretty devastating when when you're so emotionally connected to the mission like a lot of us are because as as you've come to learn the mission is really built around the ability to drill and analyze this drilled samples and those laboratories so the drill stopped working about a year ago it just kind of became unreliable didn't actually stop working and so we spent about six months trying to resuscitate it trying to figure out if we could write different software for it you know do anything we could do it this way to do it that way whatever it would like we tried it and and we couldn't really get anywhere and so then we spent now about eight months after that initial six months trying to figure out and when I say we I mean the engineers again I have nothing to do with this I'm just the end-user the engineers at JPL spent about eight months figuring out if they could redesign the entire way we drill to avoid the use of that broken part which is really remarkable so the I'll show a little video three-minute video that summarizes this but the the main motor that moves the drill up and down stopped working and and yet the engineers were able to find a way to one hundred million miles away test on earth using our backup test rover on earth that we have at JPL invent a whole new way of drilling that was safe and reliable to use on Mars and then then actually command it to try this first drill hole we haven't hit the home run yet in the sense that we've drilled this small hole and we still need to drill a deeper hole to be able to get enough material to deliver to the instruments and this one didn't quite do that but still until yesterday we had been a whole year without drilling on Mars and so quite happening and yeah [Applause] here's that story since curiosity landed on Mars in 2012 it's used its drill to acquire samples from Martian rocks 15 times but a little over a year ago in December of 2016 curiosity's drill started giving it problems the drills feed mechanism which is responsible for moving curiosity's drill bit into and out of rocks didn't move when commanded when curiosity drills into a rock the way it was designed to you the drills to stabilizer posts touched the rock first to steady the arm while the drills feed mechanism moves the bit forward into the rock without the feed mechanism working we can drill that way to solve this problem we do what we always do we worked it out in the test bed using curiosity's twin on earth our team of engineers and scientists have been working for months to figure out a way to collect and deliver rock samples without using the feed mechanism here's what we came up with using our new technique called feet extended drilling the stabilizers are not used the bit is now in a forward position extended past the stabilizers moving the drill straight into a rock and retracting safely without the stabilizers is challenging we move the arm instead of the feed mechanism to place the bit onto the rock and press it forward as it drills after making contact we apply a light preload and drill a shallow high level we use a force sensor in the robotic arm to give curiosity a sense of touch this lets curiosity adjust its arm motion and avoid getting stuck law drilling kind of like you might adjust your arm while drilling into a wall at home after drilling we use a similar technique through a track from the hole without getting stuck we recently tried this method using curiosity on Mars and here's how it turned out this picture shows the first hole drilled on Mars ever with this new drilling technique even though we can't see the hole in this image we know we drilled about one centimeter deep the hole itself is buried under the powder generated during drilling this is a good sign for the new drilling method next we have to drill a deeper hole to collect sample and demonstrate our new techniques for the the sample two curiosities to onboard labs that will come in the days ahead [Applause] yeah that picture in that video literally is on the website about three hours ago glad it was in time for this lecture so I think the last two pictures here before we end this is one we took from our position now a thousand feet high on the mountain and we could for the first time we what we took sort of turned a corner got behind we got above a little blockage and we're able to see all the way back to the landing site for the first time so we landed here and then we drove over here made those discoveries at Yellowknife Bay and then continued on and the this this mountain range here is the far side of the crater that's like 30 miles away from where we are on the central mountain so we're looking across this 30 mile crater floor and here's the mountain so my final thing here is just to give you one slide of what's coming curiosity played an important role in the Mars program by understanding the habitability of Mars and you know it was a habitable planet this you know the evidence now is really strong that we've determined that three to four billion years ago Mars could have supported life the question is did life ever arise and and that's exciting that we can ask that now because curiosity could have had a very different answer so now it's up to future missions to go look for actual evidence that life was able to use that habitable environment and so the 2020 Rover mission which launches in 2020 is built on the same platform as curiosity but carries a payload that is designed to detect ancient signs of life as we talked about it's very challenging so the machine that the instruments that we're bringing with the rover may or may not succeed in that but what this Rover also does is collect the samples that it drills puts them in little vials that are sealed on Mars and puts them in the canister so that one day a future mission can bring that canister of samples back to earth and we can use all the very best laboratories on earth to understand if any of those rock samples contain evidence of life so this is not only a really neat mission that's the next step in understanding life on Mars it's the first step in returning samples from Mars to earth and with that thank you very much okay so the first question we find about the ancient atmosphere yes I could talk for like five hours about everything we've found which is very frustrating because I want to tell you everything but we had this whole other experiment we could do with one of our laboratories to suck in Mars air and understand what it's made out of and one of the things you can do is look at the composition of the air today specifically what's called the isotopic composition of the year molecules have light versions and heavy versions and you can measure how many light versions and heavy versions there are and what that tells you is that when if Mars atmosphere was lost over time like we think it has been you and you end up retaining a lot of the heavy ones because the light ones escape so Mars atmosphere has a lot of the heavy versions of different molecules whether it's carbon dioxide water and that fits with this long-standing theory that the reason Mars went from wet to dry is because a great big percentage of the atmosphere has been lost to space so that's one of the things we were able to find out from the atmosphere and we'll 2020 have labs like Viking not quite the same ones one of the things that Viking did in 1976-77 was to attempt to feed microbes in the soil and see if metabolic products came off like sort of actively look for life living that's not the kind of thing that 20/20 does it's more looking for what's called bio signatures patterns of chemicals isotopes minerals that don't form naturally but more commonly formed because of life so it's looking for bio signatures but not actively looking for living life okay yeah a couple quick questions first thanks for the great presentation I'm planning on visiting JPL in the next couple of months and I'm wondering is it possible to see the twin curiosity when when I go down you can there's we have two models of curiosity the real one and the fake one kind of okay so anybody can see a full-size wood and plastic bottle of curiosity that's one of the things that all the tour groups go see so you good that it's neat in itself because you can appreciate the size of it and look up close it's pretty well made the actual one that you saw in the video and the one that's here actually this is in a place called the Mars yard at JPL which is a like a football field sized area that's made to be like Mars it's the rover proving grounds we have the test Rovers climb Hills and learn how to navigate and that's where this model lives which is one that's very similar to the one actually on Mars because it's very precious it spends most of its time in a shed and kind of not open to the public but if you happen to be lucky and maybe this is like half the time it'll be out in the ground and you can see it okay also I was wondering you have an awareness like right now on the day/night cycle in Mars like is curiosity in daylight right now or nighttime do you know it would be probably in daylight now Mars has a 24 and a half hour day believe it or not it's coincidence there's nothing magical about 24 hours it just happens to have a 40 minute or so longer day than Earth which means that we stay in sync with Mars for about three weeks and then we are out of sync for about three weeks and that that's that's sort of the cycle I'm going to digress because you asked a fun question one of the things that we do when we land on Mars the most efficient way to operate these missions especially when you're worried about it dying and you have this precious thing that actually is on Mars you want to stay in sync with it so you get every minute out of it so we actually live on Mars time for about 90 days where we adjust our bodies to 24 and a half hours or we try to anyway you you tape out your windows at home you talk your family into it and for about 90 days you come to work 40 minutes later every day and the reason it's 90 days because every goes crazy after that but at least for 90 days you get to operate it maximally and now we operate it every day for three weeks and then when we're out of sync we operate it every other day and it turns out this long answer to your question we're out of sync when when Mars and Earth are daylight at the same time because what we'd like to do is it's daylight on Mars the rover's doing its thing while we're all sleeping then we wake up the next morning we spend eight hours planning and we send the commands up just as the sun's rising on Mars we can only do that about three weeks right now we're in one of the cycles where we're in sync meaning that as now it's getting dark here it's getting light on Mars thank you yes my question is about one of your other research interests the weather on Jupiter quoting from Frank Sinatra song let me see what spring is like on Jupiter and Mars so wondering what you can tell us about spring on Jupiter I won't spend too much time but before this mission I was involved in a mission called Galileo which was the first orbiter in sent two to Jupiter all the missions prior to that were ones that just kind of flew by Voyager pioneer but we we spent a few years around Jupiter in orbit and one thing about these planets there that are far from the Sun is that they only go around the Sun timescales of like 10 20 30 years so sort of a short glib answer to your question is that spring is very long on Jupiter yes first of all thank you for a fascinating lecture so I have a question about whether or not there seems to be some evidence that there's water underneath the sand and there's still liquid water there and if so what do you think is the possibility that there might be microbes that survive from when Mars was habitable and still just sitting there and giving off methane possibly and I no they detected methane and they're up and seem that say oh it had to be life and oh no we've got another explanation so where do you fall on that yeah so one of the other fascinating discoveries that I had no time to talk about until now is we equipped the rover to follow up on an earth-based discovery of methane on Mars and not just methane but variable methane that's the important part because when chemists study methane on Mars they they conclude that actually that it should not vary any faster than about 300 years it's pretty that's sort of its life in the atmosphere but the earth-based observations we're seeing variations on this you know much faster than that meaning something is actively producing it and or something is actively destroying it and when you talk about something that produces methane and you get pretty excited because on earth's a lot of that is life and so we equipped curiosity sort of at the last minute to follow up on this and have determined also that methane varies pretty regularly annually so much faster than 300 years but also we found a tenfold spike that happened in just in a few days and so we are hesitant as any good scientist should be to jump to the conclusion of life so we're now going through the process of trying to come up with any non biological explanation and either come to believe that that's more likely or rule it out and so we you know we have an explanation now for the background that seems to make sense we're constantly new material is being deposited on Mars from meteors and dust that contains organics and those organics are released because they break down when they get to Mars because of all the radiation so that can that can provide this annual cycle but we have no explanation yet for those spikes so it's still an ongoing question and overall I think there could be life on Mars today much less likely than life in the past but if it were on Mars today it would have to be underground protected from the harsh surface environment thank you thank you so much for your talk how do you deal with sample Kent contamination you from Robert the rover parts themselves or cleansing the test chamber so that you're assured that your next sample is pure yeah the main way we control contamination is when we actually building the rover because the the probably the the biggest source of contamination we worry about is is bringing stuff from Earth the people who made it just contaminates from the clean room that was built in so most of the cleaning and contamination control was done during the actual building of it once we're on Mars we can not do too much to clean from one sample to the other but what we can do is all that all the places where sample travels through the drill and through all the equipment that delivers it to the instruments they're made out of very smooth surfaces and we have a lot of machinery on the rover that that shakes things and wax things so very much the way you know you might do it if you were trying to clean something on earth without water very fine powder sticks to everything and so you just give it a good whack and you get as much out the other thing we found works pretty well is sand so we can scoop up some sand and that really cleans out and paltry polishes all the all the surfaces so we know we're getting some contamination from one sample to the next but we do our best to clean everything as well as we can without water okay other planets in the solar system have moved around in the course of the solar system I think there's a popular theory that Uranus and Neptune have swapped places and Saturn and Jupiter or once on a two-to-one resonance and that's not true now so I wonder if there was a period in time for at least a few million years where Mars was significantly closer to the Sun than it is now and could that be the explanation for the warmer climate yeah I mean that that would help explain things quite a bit there's no evidence or modeling so far that that supports that although I think people look for those sorts of things in the inner solar system too most of the changes in orbit have been in sort of the outer solar system just to expand on the problem that you're describing the reason there's there's actually a pretty big paradox for some of the results that I've shown in the sense that not only well there's two problems I'll try to summarize these quickly when people put a sick atmosphere on Mars and even fill it with carbon dioxide a greenhouse gas even then at the orbit distance that Mars is it's not warm enough to make that nice wet weather system that I was describing that was needed and that's even made worse by the fact that the Sun our Sun got warmer over time and three four billion years ago it was only about 75% as as warm as it is now so it makes it even harder for early Mars to be wet so we haven't answered how it could be that wet yet in your slides you're showing that the period of wet Mars with lakes and running water and things existed over a couple hundred million years in that range which seems like a fairly stable situation so what all sudden could change to cause the climate to change this radically as it has yeah the the primary idea is that the atmosphere was lost to space but much of the atmosphere the gravity to change the size of it stayed the same so it's just a very gradually slow process of losing the lighter molecules right so what happens is two things Mars isn't doesn't have a strong gravity as earth does so some molecules literally do just escape over time they do on earth to just less but another major difference is that Mars that Earth has a magnetic field that serves to kind of shield our atmosphere from the Sun the radiation and and solar wind from the Sun that strips away the atmosphere of Mars which is not protected by a magnetic field and one idea is that early in Mars history it did have a magnetic field but because Mars cooled faster than the earth being a smaller planet it lost its magnetic field at some point became vulnerable to the solar wind stripping away the atmosphere and that's what led it to its present state thank you for your presentation so it seemed like 15 samples was in a huge sample size for the the mission so why is it that I was only 15 rather than like a thousand samples what was some of the main limiting factors yeah no it's we'd love a thousand samples the it really is just a practical limitation it takes a few weeks to go through an entire sampling campaign from choosing a site making sure the site's safe having the drill do its thing analyzing the samples so we you know we sample and we drive and we sample and we drive and we sort of strategically do that so that over the end of the mission we we make the distance we want to make and get as many samples along the way as we can so we were on a good roll we were doing like six seven a year at the point where the drill stopped working so we probably would have had 25 or so by now which isn't a thousand but but that's the real answer it's it's it's just a trade-off between all the other stuff we do and then taking the two weeks to sit in one place while we're sampling thank you last couple in all your example images as far as I could tell look like they were all sedimentary rock formations yes I was wondering if there are any outcroppings that you've been able to find of igneous or metamorphic rock formations that would be in a position that you could drill in sample yeah so with curiosity we've found the only sedimentary rock which for our purposes is great because sedimentary rock means rock that formed from sediment being brought in by winter water in this case a lot of water igneous rocks ones that formed like under a volcano or from a volcano that sort of thing we found just cobbles which is also neat because it means water eroded parts of the crater rim that are igneous and then brought the little cobbles down to where we can see them so they're rare but we have found cobbles that are sort of like the size of my fist that have big crystals in them that tell us they were actually formed in a magma chamber weight not not big enough to drill unfortunately that we have studied them chemically with our other sensors do you have the ability to get into any media collision craters that might expose older rock no we you know we probably can only so we're in a hundred-mile crater and over the mission we're gonna drive 2030 miles max so we our home is Gale Crater in our in our life will be spent on the mountain inside Gale Crater ok sure thank you for this talk and raising public awareness about the rover I've heard about in the news but you kind of help make it exciting so my question is are there other missions plan to other planets or other moons a few years ago I saw this movie called Europa report which some astronauts go to one of the moons of Jupiter to look for life and it's very traumatized but yeah can you can you speak to any other potential Rovers Europa or other sure other places are maybe Mars again yeah so I obviously love Mars and I'm not gonna be shy about that although I do have unlike a lot of my colleagues I have this history with Jupiter that makes me a little suspect to them sometimes but there's a kind of a informal you know competition between Mars which is dominated so much of NASA's attention and funding and everything else and the everything else crowd is starting to really get their day in the Sun of course you can add Cassini and with Galileo we have these great but they want to you know we want to land somewhere and so what's changed the equation a little bit the reason Mars has gotten so much attention is because it's one of the other places that had clear evidence of all this liquid water but now with Galileo is the first to find this actually the moons of Jupiter and now Saturn and we know to have shells of ice that have entire liquid oceans underneath them today so dang it unlike us they have liquid water now and so there are missions being planned as we speak to go land on Europa a moon of Jupiter and look for any water that may be coming out through the ice shell for example as a moon called Enceladus which has cracks in the ice where the water is geysering out today there's Titan which has rain today that's made out of hydrocarbons the raw material you know that life would need so there's a lot of cool places to go a problem is that they're very far away compared to Mars and and and require a lot of technology that doesn't exist yet so we're getting there but there I think the area of Mars as much as I hate to say this may be winding down and the era of Europa and others may be ramping up thank you last question we already have quite a few Martian rocks here on this planet they flew here by themselves landed as meteorites I'm honoring have any of them proven to be interesting do they look somewhat similar to how the rocks that you're landers been studying on on the planet itself yeah so two quick answers about that I mean those samples of course are extremely valuable so they've been studied more than most rocks on earth and what happens is you can go to places like Antarctica where there's white ice and the white ice is sort of turning up and keeping stuff that falls on it at the surface and so it's a good place to go hunt for meteorites because you can find them against the white snow and ice and you go collect them it turns out when you go to Antarctica and collect meteorites a decent fraction are from Mars and some are from the moon and you know and some are from the ones that actually just you know came from somewhere else asteroid belts or somewhere and so we have something like twenty or thirty Martian meteorites now and they tend to be from the volcanic sort of places on Mars a plate something like this like a mud stone from a lake wouldn't survive the journey der so we don't unfortunately it's there's a bias to what you get from Mars you get the very hard volcanic rocks so you wouldn't be able to learn this stuff but I'll just end with one story that you know I just think is really cool is that you you can look at these meteorites from Mars and you can draw out the gas from little bubbles that are trapped inside the meteorite and you can sample the Martian atmosphere from a meteorite they land on earth and you can measure its composition and you can measure its isotopes and now that we've landed on Mars especially with curiosity and the and the accuracy that curiosity's instruments have you can actually see the exact same gases and the exact same ratios exact same amounts and you can look at it like you know curiosity is the final proof that these meteorites are actually from Mars even though we sort of believe that a lot so far thank you [Applause] you

Channel: SVAstronomyLectures

Views: 46,950

Keywords: astronomy, science, astrophysics, science news, Mars, planetary astronomy, Curiosity Rover, Ashwin Vasavada, Mars exploration, JPL, planets

Id: KP18C1zjuSs

Length: 90min 43sec (5443 seconds)

Published: Sun Mar 25 2018