1 00:00:06,590 --> 00:00:10,730 Well, thank you very much, Don. And once again, I thank everybody for inviting me. 2 00:00:10,740 --> 00:00:14,120 It's great to see some old friends and and make some new friends. 3 00:00:14,120 --> 00:00:19,760 And I'm going to share with you what is about ten years worth of effort in the mission. 4 00:00:20,630 --> 00:00:23,810 I won't be offended if people get a bit bored and leave. 5 00:00:23,840 --> 00:00:29,600 I was told it might be okay to go over my time a little bit and I had a lot of fun with Robotics Group. 6 00:00:29,600 --> 00:00:35,120 We actually met twice, so I stuck in some stuff I normally don't show to show you. 7 00:00:35,150 --> 00:00:37,670 Tell you about our flat tire on on Mars. 8 00:00:39,050 --> 00:00:49,190 And I think that the the place I really have to begin here is well with Mount Sharp, which is what we're exploring with the rover. 9 00:00:49,580 --> 00:00:53,930 The rover right about now is up on this ridge that you see right there. 10 00:00:54,260 --> 00:01:03,049 It's about five kilometres high. This mountain and the crater that we landed in is about 150 kilometres across. 11 00:01:03,050 --> 00:01:08,060 And so part of the problem that has nothing to do with habitability is what is this mountain doing in the middle? 12 00:01:08,240 --> 00:01:12,410 And I don't have a great answer for that, but we'll touch on it a little bit. 13 00:01:15,980 --> 00:01:22,560 Let's see here. Now that'll work. 14 00:01:23,160 --> 00:01:30,540 Okay. So this is the part of the team that that we were formed of when we first landed back in 2012. 15 00:01:30,550 --> 00:01:35,970 This is about 200 people that are responsible for the operation of the rover on a day to day basis. 16 00:01:35,970 --> 00:01:42,630 But the broader team is 500 scientists representing 13 countries, nine principal investigators, 17 00:01:43,440 --> 00:01:47,880 ten instruments that make various measurements in addition to 17 cameras. 18 00:01:48,390 --> 00:01:55,080 So the goal, my responsibility was principally to make sure that the rover was optimised, 19 00:01:55,590 --> 00:02:04,500 to collect data and and sort of keep moving in the same direction to create the path of discovery here. 20 00:02:04,530 --> 00:02:09,780 So really what I'm showing is a lot of data from instruments that I didn't build 21 00:02:09,780 --> 00:02:15,690 in science team members who who contributed a lot to the data interpretation. 22 00:02:16,680 --> 00:02:23,940 I think what I want to do is start by talking about some of the things that puts Mars into a more earth-like 23 00:02:23,940 --> 00:02:30,300 context so that some of you that are not geologists and geochemists can better appreciate what we're doing. 24 00:02:30,750 --> 00:02:36,239 And in my experience with with Mars, it takes a long time to get used to it. 25 00:02:36,240 --> 00:02:40,650 When you're used to working on the Earth and there's a lot of history to learn about to go through. 26 00:02:40,660 --> 00:02:46,260 And so for me, this this history really begins with the Mariner mission at back in the sixties, 27 00:02:46,260 --> 00:02:50,309 which was the first time that geologists ever got to see pictures of the surface 28 00:02:50,310 --> 00:02:55,140 of Mars that shows evidence for some kind of flowing fluid in back in those days. 29 00:02:55,470 --> 00:02:59,490 They weren't sure it couldn't be liquid CO2 or even liquid nitrogen. 30 00:02:59,820 --> 00:03:02,940 But you see these channels back in the Mariner nine data. 31 00:03:03,270 --> 00:03:09,719 Viking comes in about five years later with bigger and better cameras, and the channels didn't go away. 32 00:03:09,720 --> 00:03:19,200 They just got more refined. And so and as the decades went by, that the debate slowed down and most people accepted that these were cut by water. 33 00:03:19,200 --> 00:03:24,810 And then the question became, what happened to that water? So it really becomes a story of environmental evolution. 34 00:03:25,440 --> 00:03:34,349 But the geologists really missed an important part of this problem, which is what happens to the mass that is represented by these channels. 35 00:03:34,350 --> 00:03:37,110 These are bedrock channels. Where does that stuff go? 36 00:03:37,650 --> 00:03:46,710 And so when I first got involved, I always wondered, why aren't people asking this question about where these materials are that were eroded away? 37 00:03:46,830 --> 00:03:53,580 And so there was what I regard as a very big breakthrough by the Mars Global Surveyor mission, 38 00:03:53,580 --> 00:03:59,819 which took these pictures that showed unequivocal evidence for deltas in the rock record of Mars. 39 00:03:59,820 --> 00:04:03,209 And, of course, if you conserve that mass, that's where it winds up. 40 00:04:03,210 --> 00:04:10,830 It goes downstream. But the most important thing is, is that the structure of this feature indicates that there's probably a body of standing water. 41 00:04:11,820 --> 00:04:17,309 And now the discussion of paleoclimate gets really intensive because the implication 42 00:04:17,310 --> 00:04:21,180 of a body of standing water is that it's an equilibrium with the atmosphere. 43 00:04:21,660 --> 00:04:29,730 So that Mars may have had an atmosphere that was more like Earth's the channels that you saw in the picture before, you could be a flash in the pan. 44 00:04:29,970 --> 00:04:35,760 There's an eruption of water. It flows across the surface of Mars, the channel, the water goes away. 45 00:04:36,000 --> 00:04:38,550 And the climate of Mars is not much different from Earth. 46 00:04:38,910 --> 00:04:47,520 But what this picture really required for many of us was that there there should someday be evidence for a wake. 47 00:04:49,130 --> 00:04:52,400 Okay. But before these rovers landed, all we could do is map. 48 00:04:52,550 --> 00:04:58,400 And so this was some mapping that was done by the the team that worked back in the 1990 and early two, 49 00:04:58,400 --> 00:05:03,600 thousands plotting the distribution of these channels, which basically straddle the equator. 50 00:05:03,620 --> 00:05:08,120 They're not observed at higher northern latitudes. And then when I got involved, 51 00:05:08,120 --> 00:05:12,589 what I did was work with my students was to plot the location of just layered rocks 52 00:05:12,590 --> 00:05:18,169 that could be sedimentary deposits that would balance that mass on a global basis. 53 00:05:18,170 --> 00:05:23,450 And not surprisingly, where you see the evidence for erosion, you also see the evidence for deposition. 54 00:05:23,690 --> 00:05:28,880 But you don't know that these layered rocks aren't volcanic. You don't know that they're windblown materials. 55 00:05:29,180 --> 00:05:36,980 They don't have to relate to water. So it still requires vehicles in situ to make measurements and show what these were. 56 00:05:38,270 --> 00:05:40,669 If you go back to the Viking era again, 57 00:05:40,670 --> 00:05:47,660 the history of of wearing was shown in this first image that came back where what you can see is that this valley, 58 00:05:48,380 --> 00:05:53,000 this, this Vallis Marineris, this this canyon is about five miles deep. 59 00:05:53,570 --> 00:05:59,840 And in the upper reaches of the canyon, you see a light toned rock giving way to a dark toned rock, 60 00:05:59,840 --> 00:06:03,320 which is eroding and shedding material down across it. 61 00:06:03,680 --> 00:06:12,950 So that suggested that there was some wearing present in in the upper crust of Mars, but we still didn't know what those things were in this one. 62 00:06:13,010 --> 00:06:18,620 This discussion went on for decades until the Opportunity Rover landed in 2004. 63 00:06:19,040 --> 00:06:24,619 And those of us that woke up in the morning and saw this this picture realised 64 00:06:24,620 --> 00:06:28,579 that this this really did have to be some kind of a sudden entry material, 65 00:06:28,580 --> 00:06:29,990 not a volcanic deposit. 66 00:06:30,500 --> 00:06:38,149 And so the cool thing about it is, is that you can see that everything below this white line is sort of tilted with respect to this line, 67 00:06:38,150 --> 00:06:43,400 and everything above it is flat lying. And so you can see geometric discontinuities. 68 00:06:44,000 --> 00:06:49,340 And the funny thing about that is that we could fantasise a little bit that we were looking at sticker point, 69 00:06:50,150 --> 00:06:55,490 and we don't believe that our unconformity represents the discovery of plate tectonics. 70 00:06:56,420 --> 00:07:01,490 But really it's kind of those you may recognise this fellow and at least one person does. 71 00:07:01,500 --> 00:07:12,020 That's James Ray for scale there. And and so the point is, is that really what we do is comparative planetary analysis for the first time. 72 00:07:12,620 --> 00:07:20,209 And the analogue that we do draw a comparison with is and that is in the desert of Namibia where you 73 00:07:20,210 --> 00:07:28,310 see ancient sand dunes that leave behind this dipping strata as evidence of the migration of the dune, 74 00:07:29,090 --> 00:07:32,840 which is then deflated and overlain by a water rich deposit. 75 00:07:32,840 --> 00:07:36,500 This playa lake deposits it's dry most of the time, but it does get wet. 76 00:07:36,890 --> 00:07:39,850 And that turned out to be the signature of these sediments here. 77 00:07:39,860 --> 00:07:46,460 These look like ancient sand dune deposits, and these looked like deposits that were formed in some type of apply a lake. 78 00:07:47,180 --> 00:07:53,180 But the geochemistry of this place a week, that's something that Nick Tasca worked on, turned out to be very acidic. 79 00:07:53,660 --> 00:07:56,960 And so this wasn't the perfect place to make a case for. 80 00:07:57,230 --> 00:08:01,010 If life ever evolved on Mars, could it live in that environment? 81 00:08:01,010 --> 00:08:04,819 That's what we mean by habitability. It's an existence proof. 82 00:08:04,820 --> 00:08:08,450 If life evolved, could it live in the place that you just discovered? 83 00:08:08,780 --> 00:08:17,180 And so here it's possible because some types of microorganisms do live in very strong acids, but it's not the perfect place. 84 00:08:18,110 --> 00:08:22,429 But in terms of sort of the modern environment, this is what we drew an analogy with. 85 00:08:22,430 --> 00:08:29,480 And this was something that I got exposed to in the year I spent in the Sultanate of Oman working with Bruce LaBella and others. 86 00:08:29,780 --> 00:08:36,379 You go out to the empty quarter and this is a type of environment that we think we had on Mars at the time, generally very dry, 87 00:08:36,380 --> 00:08:42,950 but once in a while it rains really hard in the Oman mountains and then 100 kilometres away that 88 00:08:42,950 --> 00:08:48,709 that rainfall eventually surges to the surface maybe maybe decades later after the rainfall. 89 00:08:48,710 --> 00:08:52,430 But it does get wet and then that water is there temporarily. 90 00:08:52,430 --> 00:08:58,249 And when it dries out, it leaves its salts behind. And this is what we think happened at that location. 91 00:08:58,250 --> 00:09:03,200 We discovered with the Opportunity Rover was a salty, acidic environment. 92 00:09:04,820 --> 00:09:11,000 Okay. At the same time, that Opportunity was making those discoveries of these sulphate salts that were there. 93 00:09:11,720 --> 00:09:17,600 There was a European space agency mission called Mars Express that had an instrument on it called Omega, 94 00:09:17,990 --> 00:09:21,890 which is an imaging spectrometer that looks down at the surface of the planet. 95 00:09:22,310 --> 00:09:28,520 And it went back to these same valleys that I showed the picture of with the steep wall rock. 96 00:09:29,000 --> 00:09:35,810 And in this interior valley, which was very strange because there's just a closed depression here, 97 00:09:36,200 --> 00:09:39,499 which then goes into one of these eroded bedrock channels. 98 00:09:39,500 --> 00:09:45,860 And so this becomes a place where people imagine that maybe water gushed up and then ran out across the surface. 99 00:09:46,370 --> 00:09:52,180 But with the higher resolution and. What people noticed was, is that there was a mountain in the middle. 100 00:09:52,190 --> 00:09:55,130 It's just down in the corner here. It's that mountain right there. 101 00:09:55,400 --> 00:10:00,890 And it's separated from all the rest of the rocks that go around the southern end of this enclosure. 102 00:10:01,430 --> 00:10:08,510 And the cool thing about it was when they looked at it, they found the same kind of salts that we found with the Curiosity rover. 103 00:10:08,900 --> 00:10:15,140 And so this is a perspective view, and this is about two and a half kilometres of relief here. 104 00:10:15,680 --> 00:10:19,700 And the interesting thing about it is you don't have to be a geologist to recognise that this 105 00:10:19,700 --> 00:10:25,490 stuff up here just looks different from everything that's down below this layer right here. 106 00:10:25,940 --> 00:10:30,050 And it turns out that if you look straight down on it, that's what this map is. 107 00:10:30,380 --> 00:10:38,300 And so this blue stuff that you see here is the top of the hill and the red stuff is the base of the hill wrapping around. 108 00:10:38,660 --> 00:10:44,210 And these are two types of salts. This is a magnesium salt and this is a calcium salt. 109 00:10:44,840 --> 00:10:46,460 And they have different solubility. 110 00:10:46,540 --> 00:10:53,510 And it all adds up to a story where probably there was water, but it was very salty and it dried out and may not have lasted for a long time. 111 00:10:55,370 --> 00:11:02,120 Okay. And so but for me, I think as a geologist in a stratigraphy and what was so exciting about this is 112 00:11:02,120 --> 00:11:07,519 that this is really the origin of the study of compositional layering on Mars, 113 00:11:07,520 --> 00:11:11,419 because with the imaging spectrometers, you're not just mapping textures, 114 00:11:11,420 --> 00:11:16,310 you're also mapping the mineralogy of the rock at the same time that you map the textures. 115 00:11:16,880 --> 00:11:25,340 And so the state of that art, if you will, is is not a lot different from the history of exploration in your country right here. 116 00:11:25,760 --> 00:11:29,270 And I really love to draw a comparison to this, because effectively, 117 00:11:29,270 --> 00:11:38,780 this is what William Smith did about 200 years ago when he mapped the layers of of England and was able to learn much about their composition. 118 00:11:38,990 --> 00:11:42,140 And if you read the accompanying notes that go along with this map, 119 00:11:42,440 --> 00:11:48,530 he realises that the discovery of these layers, these materials, will help fuel the Industrial Revolution. 120 00:11:49,550 --> 00:11:54,710 The interesting thing about this, if you look at the layers in cross-section, they dip towards the English Channel. 121 00:11:55,160 --> 00:12:00,440 And the curious thing is, is that they just stack all different compositions. 122 00:12:00,440 --> 00:12:06,200 But this one here called Chalk comes from the Latin word creature, which means chalk. 123 00:12:06,560 --> 00:12:11,810 And the important thing about that is this is a mineral name that follows the term Cretaceous to this day. 124 00:12:12,290 --> 00:12:18,590 So in Earth's own geological timescale, there is a period which is actually associated with a mineral. 125 00:12:19,100 --> 00:12:23,030 And this is kind of what we're doing with Mars right now. 126 00:12:24,140 --> 00:12:34,129 And for those of you that are not geologists, the most important thing that he was able to do and followed up by his nephew was was able to 127 00:12:34,130 --> 00:12:38,780 trace the layers because he was digging canals and he was studying the layers in the canals. 128 00:12:38,780 --> 00:12:43,849 And he discovered that even though the composition and the minerals that are associated 129 00:12:43,850 --> 00:12:48,230 with these different rocks would change sequentially as you went upward in elevation, 130 00:12:48,680 --> 00:12:52,670 the fossils that you would see approximately follow the same order. 131 00:12:53,450 --> 00:12:58,340 And so he was really on his way to discovering evolution, although he didn't know it himself. 132 00:12:58,790 --> 00:13:00,979 But it fell to his nephew, John Phillips, 133 00:13:00,980 --> 00:13:09,469 to basically put together the first time scale that subdivided the part of earth this we were most familiar with into three phases Palaeozoic, 134 00:13:09,470 --> 00:13:16,970 Mesozoic and Coenozoic, because these are separated by major events in Earth's history that represent extinctions of organisms. 135 00:13:17,480 --> 00:13:23,240 But this is kind of what we're doing on Mars, but without organisms, at least so far. 136 00:13:24,380 --> 00:13:29,660 And so a geologic time scale is essential for us to to keep going forward. 137 00:13:29,660 --> 00:13:30,740 With the lecture here. 138 00:13:30,980 --> 00:13:40,220 It's a relative ordering of geological events, and if you're lucky, you get some absolute time constraints that tell you how old those events are. 139 00:13:40,850 --> 00:13:45,590 So we have a correlate of rock property and it could be a succession of fossils. 140 00:13:46,010 --> 00:13:54,140 Or like on Mars, we look at these reflectance spectra and we see minerals and maybe we can correlate these minerals around. 141 00:13:54,440 --> 00:13:59,210 And then you combine it with some kind of a substance that you can actually date. 142 00:13:59,780 --> 00:14:03,590 And on that basis, we build a geological time scale. 143 00:14:04,630 --> 00:14:07,240 So here's our relative time scale. 144 00:14:07,240 --> 00:14:14,330 And this is something that I worked on with a post-doc, Ralph Milliken, and we took all the different strata around Mars. 145 00:14:14,350 --> 00:14:17,530 Don't try to read anything here. I know it's painful. 146 00:14:17,740 --> 00:14:25,560 Just look at the colours. And what you're going to see is that the the the rocks that are shown down here at the bottom are mostly green. 147 00:14:25,580 --> 00:14:29,410 Then they go on to mostly red and yellow, and at the top they're brown. That's all you need to know. 148 00:14:29,860 --> 00:14:35,590 And that this is older and this is younger. And we're not exactly sure how old old is and how young young is. 149 00:14:36,010 --> 00:14:41,350 But roughly, this goes from about 4 billion years ago to about 2 billion years ago. 150 00:14:41,350 --> 00:14:45,070 And then after that, everything is brown. That means the planet's really dry. 151 00:14:45,610 --> 00:14:52,120 But down in here is where people get really excited. And if you go to this place, you find lots of green stuff which are clean minerals. 152 00:14:52,390 --> 00:14:54,430 If you go to this place, you see them as well. 153 00:14:54,970 --> 00:15:02,320 But what was this one particular place really caught our eye called Gale Crater, where in principle you could go from green stuff, 154 00:15:02,320 --> 00:15:08,410 what was thought to be just a little bit of it, then into the yellow stuff and then into the brown stuff or the green or clays. 155 00:15:08,410 --> 00:15:13,810 The yellows are these sulphate salts and then the brown stuff is anhydrous iron oxide. 156 00:15:14,230 --> 00:15:20,590 So that's almost like John Phillips is three divisions subdivision of the history of the Earth 200 years ago. 157 00:15:21,670 --> 00:15:23,590 Okay. So that's a little bit of the background. 158 00:15:23,590 --> 00:15:30,820 And now we're going to look at this place, this gale crater landing site, which is the place that the science team voted for. 159 00:15:32,290 --> 00:15:43,689 And it's a fascinating place because, first of all, it straddles the Mars dichotomy boundary and this boundary. 160 00:15:43,690 --> 00:15:51,280 What the dichotomy represents is low lands of the northern part of Mars and the highlands of the southern part of Mars, 161 00:15:51,280 --> 00:15:56,560 with the steep boundary in between here. And so this crater actually straddles the boundary. 162 00:15:57,100 --> 00:16:02,470 You can see the diameter of the crater here. It's similar to these other large craters, but these don't have mountains in the middle. 163 00:16:02,950 --> 00:16:08,050 So what's so weird about this thing? It just sort of captured our our interest in our imagination. 164 00:16:08,350 --> 00:16:12,190 And then it turned out there were other important observations about the rocks 165 00:16:12,190 --> 00:16:16,420 that were in the middle of this mountain that resulted in us going there. 166 00:16:17,830 --> 00:16:24,639 And I heard a lot of interesting debates and arguments about why we should choose this landing site or that landing site, 167 00:16:24,640 --> 00:16:31,450 and it becomes a big mash up. And in the beginning, there were about 60 landing sites with hundreds of people contributing ideas. 168 00:16:31,840 --> 00:16:35,740 And then in the end, we got the Final Four and it became a decision of our team. 169 00:16:36,160 --> 00:16:41,110 And I had got to watch Bruce in action, trying to figure out how to drill an oil well on a line. 170 00:16:41,560 --> 00:16:45,790 And at the end of the day, what I discovered was everybody was lobbying for their favourite prospect, 171 00:16:46,180 --> 00:16:53,379 and the problem was nobody was listening to anybody else. So we had to change things around a little bit and then I had to go off and decide which 172 00:16:53,380 --> 00:16:56,470 one of these things we were going to spend two and a half billion dollars drilling. 173 00:16:57,250 --> 00:17:04,659 And in the end, the simplest argument to me was all the fancy spectroscopy aside, if you look at this landscape, 174 00:17:04,660 --> 00:17:09,130 you can see all these channels that we've known about since the sixties and seventies. 175 00:17:09,580 --> 00:17:15,340 We know that water runs downhill and the colour scheme here is topography. 176 00:17:15,340 --> 00:17:18,850 So the whitest, the white colours are the lowest in elevation. 177 00:17:19,360 --> 00:17:23,830 And the northern part of Gale Crater, with the exception of this crater over here, 178 00:17:24,040 --> 00:17:28,060 is the lowest part of the planet for a thousand kilometres in any direction. 179 00:17:28,420 --> 00:17:33,010 So if you want to make sure that you land the vehicle in a place where there was probably water, 180 00:17:33,430 --> 00:17:37,630 that seemed like the simplest, least sophisticated explanation and we sort of went for it. 181 00:17:39,430 --> 00:17:45,070 Okay. So this man in the middle is interesting and there's sort of two competing ideas. 182 00:17:45,970 --> 00:17:52,629 One of them is that you filled up a crater and then you eroded it away to leave him out in the middle. 183 00:17:52,630 --> 00:18:00,010 And the other one is, I call it the haystack idea, which is that they all started out flat like boles and the wind blew and in a 184 00:18:00,010 --> 00:18:04,510 pattern that piled sediment on top of each other and built a mound in the middle. 185 00:18:05,710 --> 00:18:11,170 But the authors of this paper mailing in Edgett argued that there's almost like 186 00:18:12,220 --> 00:18:17,290 a history that can be observed in different craters where you're mostly filled. 187 00:18:17,650 --> 00:18:24,160 And by the way, this is where the Opportunity Rover is. In the early days we called it Bird B, and then it landed and it got named. 188 00:18:24,730 --> 00:18:30,520 But basically, it's it's exploring the plains just outside of this enormous crater that's completely filled up. 189 00:18:30,880 --> 00:18:36,370 And then others look like they're starting to get evacuated, or alternatively, they're not completely filled. 190 00:18:36,880 --> 00:18:43,240 And then as you work your way around in this direction, Gale represents sort of the number of what might be a continuum. 191 00:18:43,630 --> 00:18:47,500 And it suggests that maybe it is the result of of erosion. 192 00:18:47,500 --> 00:18:52,960 And it seems to be that that that is the case, that we're really dealing with eroded layers. 193 00:18:54,130 --> 00:18:57,930 Okay. So it has the thickest stratigraphic section on Mars. 194 00:18:57,940 --> 00:19:04,000 It takes us through those three periods, although we're only going to explore with the rover, the very old, the stuff back at the. 195 00:19:04,080 --> 00:19:11,160 Time when they're supposed to be clays and sulphates. So here's our landing ellipse, which is about 20 kilometres in diameter. 196 00:19:11,550 --> 00:19:20,130 And because it had a landing, ellipse was able to be shrunk down because of improvements in navigation and control of this of the entering spacecraft. 197 00:19:20,520 --> 00:19:22,379 We were able to land in this mode. 198 00:19:22,380 --> 00:19:29,490 And then the idea is that you land somewhere in the middle here and then you drive out of the landing ellipse and up to the mountain. 199 00:19:29,820 --> 00:19:37,680 So we had to accept some risk that we might land on stuff that wouldn't be so good in order to drive a long ways to get the stuff that is good. 200 00:19:39,840 --> 00:19:45,329 Okay. So again, just for the non geologists, the reason we're interested in these layers, 201 00:19:45,330 --> 00:19:53,130 these these stratigraphic layers is because when you look at something like the stack of layers either at second point or down in the Grand Canyon, 202 00:19:53,460 --> 00:20:00,120 they're really records of environmental change. And that's what we're trying to do is to to understand and reconstruct the environmental 203 00:20:00,120 --> 00:20:05,010 history of Mars to see if it could have ever been a habitable place for microorganisms. 204 00:20:07,000 --> 00:20:10,870 So the history of of robotic exploration on the surface, 205 00:20:11,350 --> 00:20:21,670 it began with landers and on the Viking spacecraft they included some very sophisticated experiments to see if there was extant life on Mars. 206 00:20:21,880 --> 00:20:25,420 And they all failed. They didn't find any evidence for life on Mars. 207 00:20:25,960 --> 00:20:29,860 Congress didn't like that. And so for 20 years there was no funding. 208 00:20:30,310 --> 00:20:37,750 And then eventually NASA's came back. And in the mid-nineties we landed the Pathfinder rover. 209 00:20:37,750 --> 00:20:44,649 And the argument was, let's just accept that modern Mars is probably lifeless and get over that and think about 210 00:20:44,650 --> 00:20:49,600 the ancient rock record when we see all the evidence for water that is now missing. 211 00:20:50,080 --> 00:20:53,290 But in order to find the right rocks, you need a mobile platform. 212 00:20:53,440 --> 00:21:03,250 And so this became what was known as a it's not these two these two rovers were associated with what were called missions. 213 00:21:03,790 --> 00:21:10,690 This was called a demo because if it fails, it's not a failed mission and it's actually a true story. 214 00:21:11,170 --> 00:21:15,969 And so the Sojourner Rover, six wheel, six wheels, four wheel drive, 215 00:21:15,970 --> 00:21:21,129 the middle wheels are passive rocker bogie suspension so that you can drive over rocks that are 216 00:21:21,130 --> 00:21:28,510 equivalent to roughly the diameter of of the wheels without tilting the deck of the vehicle, 217 00:21:28,600 --> 00:21:34,510 which is paved with solar panels. So if you tilt away from the sun for too long, that's bad. 218 00:21:34,900 --> 00:21:36,760 And so you don't want to have that happen. 219 00:21:37,270 --> 00:21:43,960 And so this was really an experiment with one instrument on it that could make chemical measurements of the rocks. 220 00:21:44,380 --> 00:21:52,060 And it was very successful. And so what happened was NASA got the go ahead to the next decade where we landed the Spirit Opportunity Rovers. 221 00:21:52,390 --> 00:21:57,250 And you can see the heritage here. You have the same six wheel configuration with the rocker bogie suspension. 222 00:21:57,700 --> 00:22:03,400 The solar panels are much larger than they were on this one because we had learned more about the dust accretion rate on Mars, 223 00:22:03,640 --> 00:22:08,950 dust as always settling out. And if it settles out on the solar panel, you stop producing energy. 224 00:22:09,370 --> 00:22:12,690 So you have some uncertainty in the rate at which dust is falling down. 225 00:22:12,700 --> 00:22:16,600 So the way that you mitigate that risk is to double the surface area of it. 226 00:22:16,930 --> 00:22:21,940 We don't add windshield wipers because NASA doesn't like moving parts if you don't have to use it. 227 00:22:22,480 --> 00:22:25,690 And then what you see are the cameras up on the mast here. 228 00:22:25,930 --> 00:22:30,930 Whereas for this little guy, the cameras were on the lander and the rover can never go very far beyond the lander. 229 00:22:30,940 --> 00:22:38,200 But the idea now is for this thing to go off on its own. They were designed to last three months and drive 300 metres each. 230 00:22:38,680 --> 00:22:43,510 Opportunity is still alive 12 years later, having driven 45 kilometres. 231 00:22:44,620 --> 00:22:45,880 So it worked pretty good. 232 00:22:46,120 --> 00:22:54,399 And then NASA's got the thumbs up to go ahead to the next decade because the goal of this mission was to prove what we had seen from orbit, 233 00:22:54,400 --> 00:22:58,720 that there was this evidence for water. Once on the surface of Mars, we found that. 234 00:22:59,050 --> 00:23:03,129 And now what we do is build a much bigger vehicle that has a lot of sophisticated instruments 235 00:23:03,130 --> 00:23:10,210 to analyse the rocks for their their chemical content in ways that isn't possible otherwise. 236 00:23:10,900 --> 00:23:16,389 Same six wheel configuration rocker, bogie suspension cameras up on the mast here, 237 00:23:16,390 --> 00:23:22,270 a much bigger arm with a with a drilling rig at the end of it that takes us down seven centimetres. 238 00:23:22,810 --> 00:23:29,560 And in the back, instead of the solar panels you have a swipe that at Cape Canaveral it just like the astronauts would get and 239 00:23:29,560 --> 00:23:37,300 last what we do at Cape Canaveral with this thing is is put in the radioisotope thermoelectric generator, 240 00:23:37,810 --> 00:23:45,340 which is NASA's code for nuclear and that goes in and that's our power supply and there's a thermal couple around it. 241 00:23:45,340 --> 00:23:50,169 And so all the heat that is generated is converted into electricity and we generate 242 00:23:50,170 --> 00:23:55,870 about 100 watts of power per hour and we have lithium ion batteries on board. 243 00:23:55,870 --> 00:24:04,210 So we can store the excess power to the batteries and then run off the grid at Night-Time when we want temperatures to be cold for some analysis. 244 00:24:06,160 --> 00:24:09,129 Okay. So a lot of people ask, why does this work? 245 00:24:09,130 --> 00:24:16,720 Well, why have there been this sort of string of technical successes with these vehicles working as well as they do? 246 00:24:17,230 --> 00:24:26,230 And what I learned in associating myself with these engineers is that there's no exception to this, that you test as you fly and you fly as you test, 247 00:24:26,230 --> 00:24:32,710 and you don't build anything that you can't test rigorously and you don't do anything on Mars that you can't test first on Earth. 248 00:24:33,310 --> 00:24:36,580 And as a result of that, things generally work pretty well. 249 00:24:36,820 --> 00:24:43,000 What this engineer is doing is they have a little temperature sensor at the end. 250 00:24:43,390 --> 00:24:49,360 The rover is being illuminated with a light source that has the same intensity that the sun does on Mars. 251 00:24:49,720 --> 00:24:56,980 And they're trying to see what the temperature, what the skin temperature of all this metal is in response to that irradiation, 252 00:24:57,280 --> 00:25:05,649 to see how well it matches to the computer models which predict the thermal behaviour of the rover because thermal expansion and contraction on Mars. 253 00:25:05,650 --> 00:25:07,490 It's a. Degrees Centigrade every day. 254 00:25:07,850 --> 00:25:15,230 And with all that titanium, copper and aluminium going back and forth, that's the that's the the surest way to failure if you don't get that right. 255 00:25:17,000 --> 00:25:24,590 Okay. So we launch the rocket on day after Thanksgiving back in 2011. 256 00:25:24,890 --> 00:25:27,590 Takes about eight months to get towards Mars. 257 00:25:28,130 --> 00:25:32,720 And then eventually you enter the atmosphere and everything looks kind of like the rest of these missions. 258 00:25:32,720 --> 00:25:36,170 But there were two big differences with the Curiosity mission. 259 00:25:36,890 --> 00:25:41,540 One was the guidance and control system associated with the part where it enters the 260 00:25:41,540 --> 00:25:47,750 upper atmosphere and it ejects some ballast and it becomes almost like an aeroplane wing, 261 00:25:48,020 --> 00:25:54,889 which means it can then be controlled. And the onboard computer has a location where it's supposed to land and it's checking 262 00:25:54,890 --> 00:25:59,930 departures versus the inertial guidance system and self-correcting for that. 263 00:26:00,170 --> 00:26:04,850 That's why we can land in such a tiny ellipse. So we fly out of most of those errors. 264 00:26:05,450 --> 00:26:11,330 Then it looks like the other ones were parachute deploys, the thing decelerates to subsonic velocities, 265 00:26:11,600 --> 00:26:14,750 but then it gets totally different from any other mission that ever landed. 266 00:26:14,960 --> 00:26:24,260 The heat shield falls off and there's what's called a powered descent vehicle that flies around on its own with its own propulsion system, 267 00:26:24,260 --> 00:26:26,210 with the rover attached to the base. 268 00:26:26,750 --> 00:26:35,000 And then when it gets to be about 50 metres above the ground, it wheels the rover out on a bridle of cables, and then the rover touches down. 269 00:26:35,000 --> 00:26:40,580 The cables are cut, the descent stage goes off and crashes, and the rover is kind of born ready to go. 270 00:26:41,090 --> 00:26:49,520 So it's what it does is it reduces the risk that we're rovers in the past would have to unfold in all these complicated ways. 271 00:26:49,820 --> 00:26:54,830 If one of the devices doesn't work properly, the rover maybe may be disabled. 272 00:26:56,400 --> 00:27:04,670 Okay. So it worked. And here's the first pictures we got. 273 00:27:04,820 --> 00:27:11,060 And this was really exciting because the engineers here, all these semaphore tones and they know what's going well, 274 00:27:11,270 --> 00:27:19,099 see people jumping up and down, but you're not sure why. And then this was one of the biggest battles I actually had with the chief engineer, 275 00:27:19,100 --> 00:27:26,090 because the engineers what's happening is when we land, we plan the landing so that earth is still visible from Mars. 276 00:27:26,780 --> 00:27:32,210 And then we transmit data directly to Earth that tells us about the state of health of the vehicle. 277 00:27:32,930 --> 00:27:38,570 But then the engineers would like to have all of the data volume. But the problem is people want to see pictures. 278 00:27:39,080 --> 00:27:42,430 And and so they don't believe that things actually landed. 279 00:27:42,440 --> 00:27:49,790 And so the negotiation that I won was one picture, one black and white picture from one of the hazard avoidance cameras. 280 00:27:49,790 --> 00:27:54,140 And so what you can see here 10 seconds after we land is when the picture get taken, 281 00:27:54,200 --> 00:27:59,689 taken the lens cap is still the lens cover is still across the lens. 282 00:27:59,690 --> 00:28:02,810 So that's all this dust that you see here stuck to it. 283 00:28:03,710 --> 00:28:06,370 You see the shadow of the rover and then you get a glimpse. 284 00:28:06,380 --> 00:28:11,030 We were wondering if that could be the mountain that we had stared at from orbit for almost ten years, 285 00:28:11,030 --> 00:28:18,080 wondering if if we would ever make it there and earth sets, we get our data back. 286 00:28:18,200 --> 00:28:24,070 And then what happens is 39 minutes later, a satellite flies over the same site and we're able to get more data. 287 00:28:24,080 --> 00:28:28,450 The engineers, again, get virtually all of it, except for one more picture we're in, 288 00:28:28,550 --> 00:28:32,630 which you can now see that the dust covers have executed their command to open up. 289 00:28:32,840 --> 00:28:37,040 So you get a clear view. The shadow of the rover is longer by 39 minutes. 290 00:28:37,040 --> 00:28:42,860 And there's no question that that our mountain is there and we just have to get over there and start climbing. 291 00:28:43,850 --> 00:28:52,610 So that's all the data we get. And the rover lands at 10:39 p.m. and then the science team, the engineers that landed it, 292 00:28:52,610 --> 00:28:59,540 go in a big party and they're unemployed and the scientists basically start working. 293 00:28:59,540 --> 00:29:07,700 But the problem is we have to work on Mars time. And the annoying thing about Mars is that it rotates once every 24 hours and 39 minutes. 294 00:29:08,030 --> 00:29:13,790 So every day it's like getting in an aeroplane and flying two thirds of a time zone westward. 295 00:29:14,060 --> 00:29:19,820 And then you do it again the next day and the next day and the next day. And about every 40 days you come back in a phase with Earth. 296 00:29:20,240 --> 00:29:26,870 You're away from your family. You're holed up in a hotel somewhere painting the windows black that you're supposed to be sleeping during the day. 297 00:29:27,440 --> 00:29:32,479 And it's not much fun. But the great thing about it was there wasn't much to do. 298 00:29:32,480 --> 00:29:37,160 And we actually all went to bed and we woke up the next morning and discovered this. 299 00:29:43,340 --> 00:29:48,049 We had truly thought that nobody would be interested in this mission because soldiers, 300 00:29:48,050 --> 00:29:53,450 this cute little toaster sized rover and Spirit and Curiosity are golf carts. 301 00:29:53,450 --> 00:29:57,739 And we've got this big SUV and people are going to be bored with rovers. 302 00:29:57,740 --> 00:30:03,590 But what we totally missed was in between opportunity and and curiosity. 303 00:30:03,830 --> 00:30:07,700 Social media happened, and so we had a couple of videos that got released. 304 00:30:07,700 --> 00:30:13,129 And when the thing was successful, it got it just got spread all over the world and everybody got into it. 305 00:30:13,130 --> 00:30:17,960 But the great thing about it is this is what this is good because the taxpayers feel like they're getting their money. 306 00:30:18,860 --> 00:30:22,100 They don't actually know really what science we're doing it, but that's okay. 307 00:30:23,480 --> 00:30:27,110 So then what happens is that eventually the data comes down, 308 00:30:27,110 --> 00:30:34,370 but you need to wait for a very high bandwidth handshake with the orbiters that are going around Mars. 309 00:30:34,940 --> 00:30:38,570 And we took a 360 degree panorama with our cameras. 310 00:30:39,080 --> 00:30:46,420 And we were also interested in the mountain, in the metal that we had forgot that the crater rim itself has its own fairly imposing mountain ranges. 311 00:30:46,700 --> 00:30:51,350 And so this this is about two and a half kilometres of elevation between where we landed, 312 00:30:51,830 --> 00:30:57,980 which is this really boring spot that looks exactly like every other place a rover has landed on Mars. 313 00:30:58,250 --> 00:31:01,280 But the difference is you don't have to drive very far to get the bedrock. 314 00:31:01,700 --> 00:31:06,169 And so that was a cool thing about it. So the Sky Crane actually worked really well. 315 00:31:06,170 --> 00:31:13,430 It kept the rover away from all the interesting rocks that we landed on, this sort of featureless gravel plain with a bunch of grey rocks. 316 00:31:13,430 --> 00:31:17,120 But in the background, what we wondered was what were these layers? 317 00:31:17,450 --> 00:31:20,990 Because that was the whole reason that we were going there. 318 00:31:22,280 --> 00:31:25,820 So then eventually the rest of the 360 degree came around, 319 00:31:26,360 --> 00:31:32,600 and now we got the first images of the foothills of Mount Sharp, and we decided that this was better than the crater rim. 320 00:31:33,230 --> 00:31:41,930 And the important thing, what you're seeing here is that these layers from orbital show the data later or the interpretation of the data later. 321 00:31:41,930 --> 00:31:48,320 But these are all the things that showed these spectra for hydrated minerals. 322 00:31:48,800 --> 00:31:53,150 And that's important because it means that these rock layers formed in the presence of water. 323 00:31:53,510 --> 00:31:58,220 But we just have to drive across here about ten kilometres to actually get to the first rocks. 324 00:31:59,960 --> 00:32:05,570 Oh, yeah. No, here's, here's the slide. So here's where we landed right here. 325 00:32:05,990 --> 00:32:10,160 And this is where we need to go. In fact, we need to go all the way to this brown stuff. 326 00:32:10,160 --> 00:32:13,910 And honestly, we're about 200 metres away from it five years later. 327 00:32:14,240 --> 00:32:20,180 But the original goal was to land blast over here and start getting into all these these layers. 328 00:32:20,180 --> 00:32:22,580 But as you can tell, we got we got waylaid. 329 00:32:23,090 --> 00:32:29,690 And in fact, rather than drive directly towards well, we had to drive through these sand dunes that you see here. 330 00:32:29,690 --> 00:32:34,250 That's why we had to we couldn't go this way. We had to drive all the way around and come through right here. 331 00:32:34,790 --> 00:32:37,150 But we actually drove in the opposite direction. 332 00:32:37,190 --> 00:32:42,350 So I need to explain to you why we did that, because it turned out that we sort of hit the jackpot there. 333 00:32:44,150 --> 00:32:51,140 So this goes back to the mapping that we did before we landed. And again, what you're looking at here is it's a plot of topography. 334 00:32:51,620 --> 00:32:55,130 So these are lower elevations and the reds are higher elevations. 335 00:32:55,520 --> 00:32:59,299 And and here's where we landed. This is our landing ellipse. 336 00:32:59,300 --> 00:33:07,340 Again, it's 20 kilometres in diameter. So we landed slightly off centre, which is which is pretty good after going 300 million miles. 337 00:33:08,030 --> 00:33:12,410 And the landing ellipse is just in front of a feature. 338 00:33:13,370 --> 00:33:22,160 Not exactly the best developed thing we ever saw, but the geologists had pretty good agreement that there was a alluvial fan that represents a 339 00:33:22,790 --> 00:33:29,000 sedimentary deposit derived from erosion of a channel back up here that cuts into the crater rim. 340 00:33:29,450 --> 00:33:36,200 And so the hope was that since we were basically landing downhill of this feature that showed evidence of water, 341 00:33:36,470 --> 00:33:40,730 that maybe if we did find rocks down in this area here, they would have something to do with water. 342 00:33:41,000 --> 00:33:45,680 That was very important because our primary objective is out here. 343 00:33:45,920 --> 00:33:49,190 But if we land a break a wheel and can never get over here, 344 00:33:49,610 --> 00:33:56,389 I had to reassure the space agency that that we would actually have something to do here that would be worthy of the of the mission. 345 00:33:56,390 --> 00:33:59,870 So we did a lot of this mapping. Here's a different map. 346 00:34:00,150 --> 00:34:08,330 The plots, a property called thermal inertia. And the way to think about this is if you're not used to it, is it you're you're downtown. 347 00:34:08,330 --> 00:34:14,330 And it's a cool fall day and you walk past a building late in the afternoon and you feel the heat radiating off at you. 348 00:34:14,690 --> 00:34:15,950 That's what's happening here. 349 00:34:16,370 --> 00:34:24,110 We're making observations at night from an orbiter looking down at the ground of heat being emitted in the thermal infrared spectrum. 350 00:34:24,500 --> 00:34:32,570 And so everything that looks like it's red here is just generating more heat than than than the material that's next to it. 351 00:34:33,080 --> 00:34:38,750 And it was interesting to us that the the highest density of these red patches were out in. 352 00:34:39,860 --> 00:34:47,000 Of this feature that we consider to be alluvial fan. And it led to two frontrunner hypotheses for what that might be. 353 00:34:48,140 --> 00:34:51,560 On one hand, maybe there's a lake deposit that's there, 354 00:34:52,010 --> 00:34:57,530 and everybody that wants to find water on Mars will be very happy because we'll see cemented 355 00:34:57,800 --> 00:35:03,080 rock where the cement derives from soluble minerals that precipitate from the water. 356 00:35:03,590 --> 00:35:07,489 On the other hand, there, the people that have been looking at Mars for decades, 357 00:35:07,490 --> 00:35:11,990 they're are convinced that the reason this thing is emitting so much heat is because it's a black lava flow. 358 00:35:13,310 --> 00:35:16,670 And that wouldn't be so good for two and a half billion dollars. 359 00:35:16,670 --> 00:35:22,820 I mean, it'd be great to do the geochemistry of the lava, but that's not the first priority for the for the mission. 360 00:35:22,940 --> 00:35:26,929 And so this went back and forth, actually, and it was it was pretty tense. 361 00:35:26,930 --> 00:35:34,670 But what you can see is that your land here and when we realised and we plotted our location, we realised that's where we were. 362 00:35:36,320 --> 00:35:43,700 We just decided that for a 500 metre investment of driving in the wrong direction, we could check out some of this red stuff. 363 00:35:44,570 --> 00:35:54,110 And so we dug in actually we did this mapping before we landed and and we made up kind of a surface materials map based on the textures. 364 00:35:54,110 --> 00:35:56,480 Here's this alluvial fan that we talked about. 365 00:35:57,080 --> 00:36:02,720 And then just based on the texture we have fractured light tone, terrain, cratered, surface, smooth, honky rugged. 366 00:36:02,990 --> 00:36:07,700 They're all sort of intuitive in terms of what you would see there. But here's where we landed. 367 00:36:07,700 --> 00:36:17,030 We actually landed on the smooth, murky terrain. And then this fractured light tone terrain exactly coincides with that high thermal inertia material. 368 00:36:17,480 --> 00:36:22,130 And then the cratered surface over here looks like something you'd see on the moon. 369 00:36:22,670 --> 00:36:30,470 And so here it is. We decided to go and check it out, because for a geologist, if you get to this point right here, you've got a three fer. 370 00:36:30,860 --> 00:36:35,570 You can sample all three of these rock types. And even if they have nothing to do with water, it's still going to be cool. 371 00:36:37,130 --> 00:36:44,120 Okay. So two days after we landed, the high rise camera flew over and took a picture of the landing site. 372 00:36:44,420 --> 00:36:49,400 And here you can see curiosity for scale. And curiosity is two and a half metres long. 373 00:36:49,880 --> 00:36:57,770 And this very high albedo, this very bright thing that you see in the middle of the butterfly wings here, that's the rover itself. 374 00:36:58,280 --> 00:37:06,380 The butterfly wings are actually where the rocket motors blasted the soil away and exposed the bare red bare bedrock. 375 00:37:06,860 --> 00:37:10,940 The dark patch that you see here is where the dust was blown away from the area. 376 00:37:11,300 --> 00:37:20,150 And then this is sort of the unadulterated background, smooth, murky terrain, the cratered terrain and the light tone, fractured terrain. 377 00:37:20,510 --> 00:37:25,010 And so our goal was to basically drive and explain this to NASA. 378 00:37:25,010 --> 00:37:33,260 So five football fields and we'd be there and we had a list of hundreds of names that we had to choose from. 379 00:37:33,410 --> 00:37:37,580 And so we had to give a press briefing. And I was in a bit of a hurry. 380 00:37:37,580 --> 00:37:39,650 So I told the team, Somebody, please pick a name. 381 00:37:40,100 --> 00:37:45,890 I don't know if you guys know Kevin Lewis, but he came up with this name Glenelg because it's a palindrome. 382 00:37:46,310 --> 00:37:50,209 And so it was reassuring that we'd get the same thing when we changed our direction. 383 00:37:50,210 --> 00:37:53,930 It went from backward to forward, so that was the reason that we picked it. 384 00:37:53,930 --> 00:38:03,920 But Glenelg Scotland actually picked up on this and you can Google it and they now celebrate Mars Day once a year they adopted it. 385 00:38:04,670 --> 00:38:11,149 Okay, so when we got there, we drove across this terrain and then we got out onto these. 386 00:38:11,150 --> 00:38:16,230 You're going to see a picture from the ground of this ledge. Okay. 387 00:38:16,500 --> 00:38:24,569 Here's the ledge. And this is us crossing the boundary between the smooth hammock terrain to the light tone, fractured terrain. 388 00:38:24,570 --> 00:38:29,520 And basically the light toned fracture terrain is solid bedrock, just covered with Mars dust. 389 00:38:30,150 --> 00:38:35,910 And this stuff has some gravel and and chunks of rock and stuff like that, windblown sand. 390 00:38:35,910 --> 00:38:43,500 And that's what sort of smoothes it out. So the great thing about it was, is that when we got here we realised that we really did have solid bedrock. 391 00:38:43,500 --> 00:38:49,980 And the question was, is it a lake deposit or some kind of sedimentary deposit or is it a volcanic igneous rock? 392 00:38:51,090 --> 00:38:57,210 So we drove down in there and we got close enough and right away things started to get pretty interesting. 393 00:38:57,930 --> 00:39:03,780 First of all, the rock is cut by fractures that are filled in with some light tone mineral. 394 00:39:03,780 --> 00:39:11,220 And we have an instrument that's a laser and we hit it with the laser, got the spectrum back in it, showed it to be calcium sulphate. 395 00:39:12,030 --> 00:39:15,870 Another thing about it was this rock looks like it's got a bad case of the measles. 396 00:39:15,870 --> 00:39:19,739 There's all these bumps sticking out of it that geologists call concretions. 397 00:39:19,740 --> 00:39:27,390 You can see them down here where they're merging. And these things ultimately turned out to be quite high and magnesium and iron. 398 00:39:27,420 --> 00:39:30,120 It turns out that they're a carrier of clay mineral. 399 00:39:31,520 --> 00:39:38,569 So then the time came, we decided that this was a great rock and we wanted to drill this material and see what it was. 400 00:39:38,570 --> 00:39:44,360 Mineral, logically. So we drilled the hole and this is what it looks like. 401 00:39:44,930 --> 00:39:52,430 And what you can see is that those same white tone things that you saw on the surface, they run down the three dimensional. 402 00:39:52,910 --> 00:39:58,850 They are filled fractures. Here is the array of points where we shot into the hole with the laser. 403 00:39:59,210 --> 00:40:05,930 And this one up here hit some of the white stuff. And so we got confirmation that that was calcium sulphate in the third dimension. 404 00:40:06,350 --> 00:40:11,750 And then we also began to again see that there was some enrichment and magnesium and iron. 405 00:40:12,080 --> 00:40:16,040 But the problem is, when you look at the chemistry of this rock, it's perfect basalt. 406 00:40:16,700 --> 00:40:21,580 And so all the people that wanted it to be a lava flow, it's kind of like the spoiler really wants to win. 407 00:40:22,070 --> 00:40:29,450 They're like, it just looks like a lava flow. But the problem was when we drilled it and we did the mineralogy, we got something really different. 408 00:40:30,350 --> 00:40:38,360 And so Rocknest is a modern day Martian soil that we analysed with a bunch of unaltered, basaltic rock fragments in it. 409 00:40:38,750 --> 00:40:43,490 And these are all the minerals that make up a rock for the geologists called basalt major minerals. 410 00:40:43,940 --> 00:40:46,940 And and here they are in their normal abundances. 411 00:40:46,940 --> 00:40:50,000 And then here they are in this in this hole that we drilled. 412 00:40:50,450 --> 00:40:57,380 And you can see how they're all decreasing in importance, especially this one called olivine, which almost goes to zero. 413 00:40:57,770 --> 00:41:03,470 And then we see the appearance of a clean mineral called Smectite, which is actually an iron magnesium smectite. 414 00:41:03,740 --> 00:41:08,960 And this only forms in water and it's in here at the 20 to 30% level. 415 00:41:09,320 --> 00:41:16,340 And then there's another mineral, which is a very minor component of of the soil, which turns out to be an important component of this rock. 416 00:41:16,700 --> 00:41:19,790 Nick Toscan and his group have been doing a lot of work on this, 417 00:41:20,030 --> 00:41:27,140 and this is also a very important constraint on the fact of this rock representing an altered deposit. 418 00:41:27,770 --> 00:41:32,419 I'm going to show other pictures later on of of some even better lake deposits than this one. 419 00:41:32,420 --> 00:41:35,750 But our interpretation was that this was an ancient lake deposit. 420 00:41:37,520 --> 00:41:44,959 Okay. I want to explain some of the data from the most sophisticated instrument on the rover. 421 00:41:44,960 --> 00:41:48,800 It's called SAM, which which stands for sample analysis at Mars. 422 00:41:49,220 --> 00:41:53,549 And what you do is you take the rock powder, you drill the rock powder, 423 00:41:53,550 --> 00:42:02,420 it goes down into the rover and and then it goes into what's called the sample manipulation system into one of these these quartz cups. 424 00:42:02,900 --> 00:42:08,630 And then that quartz cup goes into an oven and we heat it almost up to a thousand degrees centigrade. 425 00:42:08,990 --> 00:42:10,370 And in cooking it, 426 00:42:10,370 --> 00:42:20,449 we release all the volatile materials and we collect those gases and then we analyse them in this spectrometer that we can feed it off. 427 00:42:20,450 --> 00:42:25,540 That way we can close a valve and send it down to a different kind of a spectrometer. 428 00:42:25,550 --> 00:42:33,950 Tuneable laser spectrometer. This actually allows us to determine isotope ratios of, of, of, of water as well as carbon and oxygen. 429 00:42:34,640 --> 00:42:41,450 And, and then we can turn another valve and send it across something called a hydrogen carbon trap, which is super cold. 430 00:42:41,960 --> 00:42:46,760 And then all the gases condense and then we can turn the valve again and heat it up 431 00:42:46,880 --> 00:42:50,630 and then liberate those gases and put them into something called a gas chromatograph. 432 00:42:51,050 --> 00:42:55,850 And from that, maybe get a sense for what organic materials might be present on the surface of Mars. 433 00:42:57,290 --> 00:43:00,770 So here's what the data looks like as it's processed and comes out. 434 00:43:02,000 --> 00:43:05,570 This is the intensity of this quadrupole mass spectrometer. 435 00:43:06,140 --> 00:43:10,490 This is temperature rising from about 250 degrees C up to about 800. 436 00:43:10,910 --> 00:43:15,770 And the first thing that happens is we produce a lot of carbon dioxide, comes out of the rock. 437 00:43:16,100 --> 00:43:22,180 There's a lot of water that gets produced. There's oxygen that comes out the carbon dioxide peaks. 438 00:43:22,190 --> 00:43:30,260 And then after that, the water peaks and then the water production drops off until you get up to about 700, 750 degrees centigrade. 439 00:43:30,530 --> 00:43:32,660 And then the water abundance comes back again. 440 00:43:32,930 --> 00:43:38,270 And what's happening there is that in this clay mineral, like clay mineral has water in it's mineral logic structure. 441 00:43:38,570 --> 00:43:45,049 You're liberating that water. And it turns out we can actually capture that water and analyse it with the Tuneable laser 442 00:43:45,050 --> 00:43:52,370 spectrometer and get its isotope ratio so we can measure the isotope ratio of water in Rock on Mars. 443 00:43:52,370 --> 00:44:00,950 That's almost 4 billion years old. And then this stuff down here, these are two forms of sulphur that come off sulphur sulphate and sulphide. 444 00:44:01,280 --> 00:44:05,210 And so this was very important in giving us an interpretation of the rock. 445 00:44:06,020 --> 00:44:13,280 I won't go into the details, but it can be simplified into a convenient story of pictures. 446 00:44:13,820 --> 00:44:18,620 And, you know, ten years ago, well longer than that. 447 00:44:18,620 --> 00:44:27,710 Now, this is what we got with opportunity. We found this wet environment and we were led there by a signature that we saw from orbit. 448 00:44:27,980 --> 00:44:34,040 And we didn't have a drill, but we had kind of a rasp. And when we rubbed, the rock erodes away. 449 00:44:34,280 --> 00:44:38,120 And the powder that is produced is red and the rock itself is red. 450 00:44:38,510 --> 00:44:44,450 And it turns out this is associated with a mineral called Haematite. And we think that Haematite formed in water. 451 00:44:44,960 --> 00:44:51,290 But the important thing is, as Nic was able to show with this postdoctoral research, this was super salty and very acidic. 452 00:44:51,620 --> 00:44:53,420 It just wasn't that good of an environment. 453 00:44:53,990 --> 00:45:02,180 When Curiosity drilled this mudstone, you can see that Mars is still red on the surface, but when you scratch below it, you now get a grey rock. 454 00:45:02,270 --> 00:45:07,250 And what that means is that the iron in that rock is not oxidised like it is here. 455 00:45:07,550 --> 00:45:11,360 It's actually more reduced. It's in this mineral called magnetite. 456 00:45:11,990 --> 00:45:16,670 And so these are two rocks from a similar kind of environment on Earth. 457 00:45:17,030 --> 00:45:19,579 It's a Triassic rip basin from Connecticut. 458 00:45:19,580 --> 00:45:28,280 And then in New York, Boston and Washington, D.C., you have brownstone buildings that are brown because of this. 459 00:45:28,280 --> 00:45:34,100 There's these kind of red sandstones. And then you have Grey Rock, which is less interesting. 460 00:45:34,430 --> 00:45:41,089 But the Grey Rocks are the ones that preserve the organic matter. So we got really excited about this because we have a much better chance to 461 00:45:41,090 --> 00:45:44,870 preserve organic materials on Mars in this kind of rock than this kind of rock. 462 00:45:46,790 --> 00:45:55,400 So the opportunity, if you reconstruct what Mars might have been like at that location, this was our favourite analogue. 463 00:45:55,550 --> 00:45:58,400 It's a it's a place called Rio Tinto in Spain, 464 00:45:59,000 --> 00:46:07,159 and there's a massive iron sulphide deposit which is being oxidised and weathered and all that sulphide gets converted to sulphate. 465 00:46:07,160 --> 00:46:14,270 It produces a huge amount of hydrate of sulphuric acid and that the acidity is so low that iron is actually soluble. 466 00:46:14,540 --> 00:46:20,359 And so the Rio Tinto because iron is actually in the F plus three state but dissolved 467 00:46:20,360 --> 00:46:25,429 in this water and then this material that you see and crusting these rocks here is 468 00:46:25,430 --> 00:46:29,899 a sulphate salt called jarrah site and you put that together and this is the stuff 469 00:46:29,900 --> 00:46:34,880 that made up these rocks that Nick documented back at the opportunity landing site. 470 00:46:35,210 --> 00:46:38,800 There are microbes. That grow there, but it's a very specialised group. 471 00:46:39,280 --> 00:46:42,370 So it is possible that this environment is habitable. 472 00:46:42,850 --> 00:46:47,320 But the reason this environment is habitable is because this is not that salty. 473 00:46:47,530 --> 00:46:52,930 It's salty, but it's not that salty. The rock on Mars was far saltier than seawater. 474 00:46:53,380 --> 00:47:01,000 And and we think it was actually an uninhabitable environment for the same reason that honey keeps on your shelf. 475 00:47:01,600 --> 00:47:07,210 Honey is an aqueous environment, but bacteria don't grow there because the water activity is so low. 476 00:47:07,930 --> 00:47:12,700 So that was kind of the bummer for that site. It wasn't the acidity, it was the salinity. 477 00:47:14,120 --> 00:47:20,149 This is kind of what we think we discovered with curiosity. Just take these higher grasses away. 478 00:47:20,150 --> 00:47:25,650 We don't think they were on Mars. And this is actually drier than what we think we had. 479 00:47:25,670 --> 00:47:28,880 These are these are prior weeks. They dry up seasonally. 480 00:47:29,120 --> 00:47:35,150 But it doesn't really matter, because what happens is if you just dig a shallow hole, the water is still down there. 481 00:47:35,540 --> 00:47:39,709 So even if the surface is dry, there's it's still saturated down here. 482 00:47:39,710 --> 00:47:49,310 Microbes grow really well because this is this rock called basalt, which weathers in place in these lakes to form these iron, 483 00:47:49,310 --> 00:47:55,130 magnesium, smectite minerals that have a very similar composition to what we found on Mars. 484 00:47:56,690 --> 00:47:59,990 Okay. So this is what it comes down to. 485 00:48:00,920 --> 00:48:04,909 We don't think that the honey was a habitable environment and what we think we found was 486 00:48:04,910 --> 00:48:11,150 sort of like a rock battery where microbes that that actually harvest chemical energy, 487 00:48:11,570 --> 00:48:19,220 just like the chemical energy that's stored in a battery you can stored in a rock and you just need iron in two different oxidation states. 488 00:48:19,520 --> 00:48:23,179 We found it and you just need sulphur and two oxidation states. 489 00:48:23,180 --> 00:48:27,560 And we found that as well. So a microbe could have been very happy in this environment. 490 00:48:27,800 --> 00:48:33,410 That doesn't mean they were there, but it's it supports the case, too, to look on in the next decade. 491 00:48:33,410 --> 00:48:40,700 And now NASA's planning the next mission. So here's what we discovered with the organics. 492 00:48:40,760 --> 00:48:45,590 It turns out to be very difficult to do this on Mars. And I'll explain why in a minute. 493 00:48:46,190 --> 00:48:49,940 But I mentioned that the first thing we did was to scoop a soil. 494 00:48:50,330 --> 00:48:56,270 And and so what we're doing here is plotting the abundance of a compound called chloro benzene. 495 00:48:56,750 --> 00:49:00,020 This is the most sophisticated molecule that we have found. 496 00:49:01,100 --> 00:49:07,460 But it turns out it's it's distributed in a in a very distinct way. 497 00:49:07,970 --> 00:49:11,750 So this is the detection limit for the instrument. 498 00:49:12,110 --> 00:49:16,970 So, you know, there is some positive value here, but we don't think that it's we just think it's noise. 499 00:49:17,210 --> 00:49:21,770 So we don't think there's any of that stuff in there. Then we drilled this first hole. 500 00:49:21,770 --> 00:49:28,340 Remember, here's the you can see the spots from the laser, here's the the sulphate filled fracture and we drilled it. 501 00:49:28,370 --> 00:49:29,989 We didn't find any of that stuff. 502 00:49:29,990 --> 00:49:36,050 But then we drilled another hole with a hypothesis that if we go to the highest concentration of all the concretions, 503 00:49:36,530 --> 00:49:41,390 maybe the concretions are preserving something that got destroyed everywhere else. 504 00:49:42,170 --> 00:49:48,320 So when we did that, this is where we found it, and it's statistically significant that those molecules are there. 505 00:49:48,800 --> 00:49:55,580 So their absence here really suggests that these organic compounds are somehow related to Mars. 506 00:49:56,210 --> 00:50:03,050 So to be sure that before we published the paper, we then went to the next rock type, which was a cross bedded sandstone, 507 00:50:03,050 --> 00:50:07,850 where we didn't expect to see much of this stuff and indeed we didn't measure it of it, 508 00:50:07,850 --> 00:50:12,860 which which means we're not we're not even passing it forward as contamination from the previous drill hole. 509 00:50:13,880 --> 00:50:18,200 So we don't really know what this means when it comes right down to it. 510 00:50:18,710 --> 00:50:25,070 We're not even sure that we're not manufacturing these when we heat the rocks up by taking other organic 511 00:50:25,070 --> 00:50:31,730 matter and taking chlorine from Mars and then combining it together to manufacture this synthetic molecule. 512 00:50:32,600 --> 00:50:33,649 We're just not sure. 513 00:50:33,650 --> 00:50:39,890 But the fact that there's an abundance of it here suggests that it's worthwhile to go back and collect this rock and return it to Earth. 514 00:50:41,150 --> 00:50:42,650 Okay, so we got all excited. 515 00:50:45,870 --> 00:50:53,010 Have a special issue of sites where we publish all our papers and this is all location of the drill site that made it on the on the cover. 516 00:50:53,820 --> 00:51:00,840 And I was up at at HQ and we as a team were presenting these results. 517 00:51:00,840 --> 00:51:05,850 It was in in December of 2013. 518 00:51:06,240 --> 00:51:13,020 So the cool thing about it was the mission is funded for two years and you get two years to basically discover something that validates the mission. 519 00:51:13,380 --> 00:51:18,240 And we found that after just six months and it just took us a while to to work up all the results. 520 00:51:19,230 --> 00:51:24,480 And so all this stuff was found here in a place we call Yellowknife Bay. 521 00:51:24,990 --> 00:51:31,740 And then after that, we hightailed it. And the idea is to drive as fast as you can over to the good stuff. 522 00:51:32,160 --> 00:51:37,590 And then we stopped at Kimberley in the blue. These blue circles represent where we did our first drill holes. 523 00:51:38,070 --> 00:51:43,350 So this is where we drilled that cross bit of sandstone and we waited to make sure there wasn't near the core of benzene 524 00:51:43,350 --> 00:51:49,020 in that hole so that we can make the argument that what we did find in the hole back here was really indigenous to Mars. 525 00:51:49,950 --> 00:51:56,510 But as we were driving along, we discovered that this smooth hammock terrain actually wasn't so smooth in harmony. 526 00:51:56,880 --> 00:52:05,270 And literally we had just presented the results and and the mission manager called me up and said, you need to come back there. 527 00:52:05,620 --> 00:52:08,340 There's, there's a problem. And so we're going to stop driving. 528 00:52:08,910 --> 00:52:16,140 And so what you can see here is in these images that a sol is a day on Mars, 24 hours and 39 minutes. 529 00:52:16,650 --> 00:52:22,050 And after 400 of these days, we had picked up a fair number of things in tents, and we expected to see that. 530 00:52:22,410 --> 00:52:26,490 But we didn't expect to see was this tear that you can see over here. 531 00:52:26,910 --> 00:52:32,430 And so we went back and we started to look at all the terrain and we're trying to figure out how in the world that this will get damaged. 532 00:52:33,900 --> 00:52:40,290 So what we did then was we aimed the cameras at all six wheels and we rotated all six wheels and took a complete set of pictures, 533 00:52:40,290 --> 00:52:43,529 and we discovered that it was actually much worse than that. 534 00:52:43,530 --> 00:52:46,560 We had realised these holes are supposed to be there, 535 00:52:46,920 --> 00:52:56,340 this array of three wide spells in Morse code and it was clever engineers and this whole just is bad. 536 00:52:56,790 --> 00:53:02,010 You're not supposed to see daylight through on their side there. And that brought the mission to a grinding halt. 537 00:53:02,430 --> 00:53:09,150 And we hadn't really made it to the place where we're ultimately supposed to be going, but it took us about six months to work through this. 538 00:53:09,750 --> 00:53:18,149 So here we catch the culprit in the act. And and what you can see is that we're driving over these rocks that have these sharp pointy edges. 539 00:53:18,150 --> 00:53:21,720 And it turns out that the wind is howling in this place that we landed. 540 00:53:22,110 --> 00:53:26,729 And it's turning all the rocks into pyramidal shapes that geologists are 541 00:53:26,730 --> 00:53:30,480 familiar with in places like Antarctica and other deserts that are very sharp. 542 00:53:31,170 --> 00:53:34,200 And the wheels honestly were just under engineered. 543 00:53:34,470 --> 00:53:39,870 They just they just couldn't bear the strength. And we didn't expect to encounter this many rocks. 544 00:53:39,870 --> 00:53:47,489 And the wheels were made to be lighter than what you might have wanted to do, because that helps with the physics of the landing problem. 545 00:53:47,490 --> 00:53:51,000 If the rover weighs less than the than the master vehicle does. 546 00:53:51,750 --> 00:53:55,079 So we we did some tests and we divided up. 547 00:53:55,080 --> 00:53:59,850 And I went off with all the scientists and we tried to figure out how can we get less of these rocks? 548 00:54:00,300 --> 00:54:04,080 And the chief engineer went off with his group and they did some experiments. 549 00:54:04,080 --> 00:54:07,560 So here you're going to see the results of these. See? 550 00:54:17,150 --> 00:54:24,380 Okay. So we call this thing the inhaler. And so we're we're basically driving the vehicle across it. 551 00:54:24,950 --> 00:54:32,330 And and what's happening is this the pivot point for the wheel is in front of the lever. 552 00:54:32,930 --> 00:54:37,730 And so what you're trying to do is basically push this thing across horizontally, 553 00:54:38,090 --> 00:54:44,810 which not only gives the static load associated with the acceleration of gravity on Mars acting on the Impaler, 554 00:54:45,140 --> 00:54:53,830 it gives you a dynamic pressure of pushing into it. So the idea became, what if we drive backwards and pull the wheels behind us? 555 00:54:53,840 --> 00:54:59,600 It's actually basic physics, but it took us six months to figure this out because we had to do all the testing. 556 00:55:00,770 --> 00:55:04,280 So here we are now. Same thing, but driving backwards. 557 00:55:11,630 --> 00:55:15,320 So it worked. Okay. So that's the first part of the problem. 558 00:55:16,040 --> 00:55:20,650 Let's drive backwards. So we made the decision that we would now drive backwards as much as possible. 559 00:55:20,660 --> 00:55:24,500 You get four wheels that are trailing instead of four wheels leading. 560 00:55:24,500 --> 00:55:30,440 So there's still two that are going to get pretty badly damaged. And then this is the part that I worked on. 561 00:55:31,250 --> 00:55:38,479 Here's where we stopped. And the black line that you see here is the route that we're supposed to be taking, 562 00:55:38,480 --> 00:55:42,470 which is effectively the shortest distance between point A and point B, 563 00:55:43,040 --> 00:55:50,390 avoiding some of the craters in the sand dunes that you see here and then adjusting for other things that look like scary terrain. 564 00:55:51,470 --> 00:55:58,340 And then so what I do is I chose let's see, one, two, three, four, five, six, 565 00:55:58,580 --> 00:56:05,210 seven different scientists on the mission who I think have the most experience with thinking about terrain and geomorphology. 566 00:56:05,750 --> 00:56:10,340 And I give them all the data that they want and they get a week to go away and come up with a preferred route. 567 00:56:11,240 --> 00:56:15,860 So how many times have geologists ever seen this before? Seven different interpretations. 568 00:56:16,280 --> 00:56:19,880 And the reason why is because there is no hypothesis. 569 00:56:20,060 --> 00:56:23,900 It's just guessing. And so some people say, let's take the high road. 570 00:56:23,940 --> 00:56:27,560 Other people say, let's take the rover. Some people will say, here's the guy. 571 00:56:27,570 --> 00:56:31,670 The green path is basically saying, I don't care. I'm still going with the shortest route. 572 00:56:32,090 --> 00:56:34,999 And then the pink guy over here says, let's take the longest route, 573 00:56:35,000 --> 00:56:39,890 because that goes through the valleys and maybe the valleys actually have more sand and less rock. 574 00:56:40,820 --> 00:56:47,330 So that was a tough sell to Nasser. We turned out to take the pink route because I'll show you why in a minute. 575 00:56:47,660 --> 00:56:53,660 But the NASA's lead engineer is saying, let me get this straight. You guys are going to take the longest route to keep the wheels safe. 576 00:56:54,260 --> 00:56:59,300 And and so we had to do a little bit more work before they accepted it. 577 00:56:59,660 --> 00:57:08,389 So we what we did was terrain mapping. So we actually blow the images up to their highest resolution and subdivided it into a whole bunch of 578 00:57:08,390 --> 00:57:15,800 terrain types that that we interpreted to have properties that would be worse or better for the wheels. 579 00:57:16,280 --> 00:57:22,519 So what you can see here is that basically we're trying to stay on the green or the blue and the green or are ripples 580 00:57:22,520 --> 00:57:29,780 where we can see alien windblown sand from orbit and the smooth looks like it should be some kind of of sand or soil. 581 00:57:30,170 --> 00:57:34,260 But what we're really trying to stay away with are these cratered, capped rocks. 582 00:57:34,280 --> 00:57:39,560 And originally we thought we'd be better off driving on the rock to stay out of out of the sand. 583 00:57:40,370 --> 00:57:46,850 So the first challenge. Gosh, it's just off screen. 584 00:57:47,330 --> 00:57:56,060 There's a gap up here that we had to drive through and to make it into this this network of valleys. 585 00:57:56,690 --> 00:58:02,270 And here's what this gap looks like. So what you can see is, is Rocky Plateau. 586 00:58:02,360 --> 00:58:05,660 These are all conglomerates and sandstones heavily cemented. 587 00:58:06,170 --> 00:58:10,070 And then here they are shedding all these sharp rocks down that we've been driving across. 588 00:58:10,490 --> 00:58:17,930 And there's a valley right here. But the problem is the valley is is occluded by a single sand dune that bridges across here. 589 00:58:18,260 --> 00:58:21,320 So the problem is we have to make it across the sandstone, 590 00:58:22,010 --> 00:58:27,410 across the sandstone in order to make it down into a valley, which we think is good, but we don't know it's good. 591 00:58:27,860 --> 00:58:32,320 So the NASA guys are all saying, you know, how do you guys how are you guys going to demonstrate this? 592 00:58:32,330 --> 00:58:36,920 And so we said, well, the first thing we should do is just go up to the edge here and put the front wheels 593 00:58:36,920 --> 00:58:41,600 up here and peer over the top because our camera is kind of like a periscope. 594 00:58:42,200 --> 00:58:49,399 So here we are peering over the top and and you can see why you wouldn't want to go racing over the top, 595 00:58:49,400 --> 00:58:53,479 because this this cliff is collapsing to produce all these blocks. 596 00:58:53,480 --> 00:58:56,000 And if you drove straight across, that would really be a problem. 597 00:58:56,390 --> 00:59:03,560 But what you can see in the distance here is that the terrain really does look pretty good, like what we had thought we were seeing from orbit. 598 00:59:03,890 --> 00:59:08,030 You know, there is some ripples. And then down here, you can see some rocks strewn around. 599 00:59:08,030 --> 00:59:15,050 But altogether, this this sort of sandy river looks a heck of a lot better than than any of these other options that you see here. 600 00:59:15,710 --> 00:59:22,580 But the problem is now we're worried about getting stuck in the sand dune. So here's here we are doing doing an experiment. 601 00:59:22,580 --> 00:59:25,880 And this is an animated gif that shows 24 hours of data. 602 00:59:26,390 --> 00:59:31,070 And what you can see here is that we did literally come up to the brink and 603 00:59:31,070 --> 00:59:36,170 we put the left front wheel just on top of the crest line of the sand dune. 604 00:59:36,530 --> 00:59:42,040 And then the right front wheel is just behind it because of suddenly we think we can still pull ourselves out. 605 00:59:42,050 --> 00:59:47,540 That's the idea. But what we do is we drive the vehicle up there and then we took a picture and 606 00:59:47,540 --> 00:59:51,590 then we wait 24 hours and take another picture at approximately the same time. 607 00:59:51,860 --> 00:59:55,490 But it wasn't exactly the same time, and that's why the shadows are a little bit different. 608 00:59:55,880 --> 01:00:03,530 But the important thing is you can see the shadows moving, but what you can't see moving are these little fractures in the sand dune or the wheels. 609 01:00:03,530 --> 01:00:07,309 It doesn't look like we're sinking. So with that, we eliminate the risk. 610 01:00:07,310 --> 01:00:15,590 Not completely, but you know that the mobility engineers are going to always invent every worst case scenario that could possibly happen. 611 01:00:15,890 --> 01:00:18,590 And so in this case, it was, yeah, there's beautiful sand here, 612 01:00:18,590 --> 01:00:24,680 but one centimetre beneath it is going to be baking flour and it's just going to sink in any way. 613 01:00:25,550 --> 01:00:29,450 So we got up the courage, we drove across it, it worked well, and then we looked back at it. 614 01:00:30,170 --> 01:00:32,510 And so here's our tracks and what you can see. 615 01:00:32,510 --> 01:00:39,770 Doing what we're doing here is driving over the crest line and we command the vehicle to your on purpose. 616 01:00:40,190 --> 01:00:49,040 And so we overdrive these wheels which steers us away from sliding down the front here and skidding into these rocks. 617 01:00:49,040 --> 01:00:55,459 And so we get most of the way down. And then you can see where we made a little trench here that comes from a wheel wiggle that 618 01:00:55,460 --> 01:01:00,830 we do to make sure that we've estimated the slip rates correctly and then we just drive on. 619 01:01:02,240 --> 01:01:05,629 So that's what we did. 620 01:01:05,630 --> 01:01:09,830 And we made it through there. And and we've been doing fine ever since. 621 01:01:10,160 --> 01:01:16,250 And here's where it took us. Eventually, we finally got to the place where we had told everybody that we were going to go to. 622 01:01:16,610 --> 01:01:21,630 And we're descending down to a place that became known as Army Ghost Valley because the guy on duty 623 01:01:21,920 --> 01:01:28,430 worked in Death Valley and suddenly we had Death Valley names and this was this rock that from orbit. 624 01:01:28,790 --> 01:01:32,080 It just doesn't show any signatures of of hydrated minerals. 625 01:01:32,090 --> 01:01:34,040 It looks like it's going to be pretty disappointing. 626 01:01:34,520 --> 01:01:40,640 But what we had learned from our first drill hole is that that place didn't show any signatures either, but it had 20% clay in it. 627 01:01:41,210 --> 01:01:43,490 And this was a big surprise to the Mars community, 628 01:01:43,490 --> 01:01:48,500 because these rocks are relatively younger and the history of Mars, and they're not supposed to have all this. 629 01:01:48,500 --> 01:01:50,870 Clay And so the question was, 630 01:01:50,870 --> 01:01:58,580 could we demonstrate that again as we drove even higher up into the stratigraphy of layers and this became our chance to do that. 631 01:01:59,660 --> 01:02:06,710 So we worked along. And again, just to give you the frame of reference, that image that you saw here, these are the propels. 632 01:02:07,010 --> 01:02:10,910 We were parked right here looking down into this Ahmed Gusev Valley. 633 01:02:11,390 --> 01:02:16,790 And then ever since then we've been drilling and we've got three or four more drill holes that I haven't plotted. 634 01:02:17,300 --> 01:02:21,890 But conceptually, this is what we learned as we drove the vehicle uphill. 635 01:02:24,470 --> 01:02:31,810 This is a plot of elevation. And and this is the small number that that we drove across. 636 01:02:31,820 --> 01:02:39,860 So here we saw 400 when we had all these problems where we tore the wheels up because we had basically driven only a short way. 637 01:02:39,980 --> 01:02:46,700 And what we interpreted to be sandstones river deposited is sand that becomes a rock. 638 01:02:47,660 --> 01:02:52,040 And then we drilled into a mudstone and then we drove across more sandstone and tore up the wheels. 639 01:02:52,040 --> 01:02:53,780 And then we learned how to drive around it. 640 01:02:54,140 --> 01:03:02,870 But we kept going uphill and all the rocks that we had been looking at look like the kind of rocks that form in an ancient river or delta. 641 01:03:03,650 --> 01:03:09,320 And then right around saw a hundred. We crossed a geologic boundary that we could see from orbit. 642 01:03:09,800 --> 01:03:14,300 And ever since then we have been in what looks like a lake deposit, 643 01:03:14,300 --> 01:03:22,700 and now we've got it accumulated about 150 metres of that stuff and and we drilled as we went along. 644 01:03:22,700 --> 01:03:29,149 So this is sort of for the geologists in the room. And I'll just leave this up here for just a minute because it's it's probably going to be our our 645 01:03:29,150 --> 01:03:34,340 greatest accomplishment is the is the mineralogy that will distinguish us from previous rover missions. 646 01:03:34,940 --> 01:03:42,110 And what we're really interested in are these kinds of things with the brighter colours that you see down here. 647 01:03:42,770 --> 01:03:48,620 These were the holes that we drilled originally, and we wrote our science papers about this green stuff in here. 648 01:03:50,380 --> 01:03:54,610 It's missing from the legend. That stuff is missing. 649 01:03:55,480 --> 01:04:02,590 This is this iron, magnesium, clay. Okay, so every place you see the green means we have this iron magnesium clay. 650 01:04:02,980 --> 01:04:09,549 The black stuff is the magnetite, which we think somehow is forms in association with that clay production. 651 01:04:09,550 --> 01:04:16,750 And Nick Tasca has some good ideas. So we left those rocks and when we got to the hills we found more clay. 652 01:04:17,110 --> 01:04:24,249 But we now had haematite in addition to magnetite, and we had some of these less common sulphate phases that you see down in here, 653 01:04:24,250 --> 01:04:29,980 especially this iron sulphate which actually now suggests we're getting into some acidity that we didn't have before. 654 01:04:30,670 --> 01:04:34,450 But then something really dramatic happens when we go up to these next. 655 01:04:34,840 --> 01:04:39,580 We get up higher into the section, most of it the haematite goes away. 656 01:04:39,590 --> 01:04:49,120 Then eventually it goes completely away. All of these acidic sulphate minerals go completely away and we have a large amount of crystal and silica, 657 01:04:49,300 --> 01:04:52,300 mostly in the form of crystal light and tritium. 658 01:04:52,300 --> 01:05:00,250 Right. And so we actually think that there might have been some, some felsic igneous rocks that were contributing detritus to the basin. 659 01:05:00,250 --> 01:05:04,270 But the biggest part of this is actually amorphous silica that I'll show you in a minute. 660 01:05:04,960 --> 01:05:08,440 The thing is, is that even though it looks like we stay in the lake, 661 01:05:08,440 --> 01:05:15,580 the chemistry of this lake and or its subsequent die genetic history are changing. 662 01:05:15,880 --> 01:05:21,250 And so the place where we have been most recently actually has the most clays that we've seen of the entire mission. 663 01:05:21,730 --> 01:05:27,730 But now we don't see any magnetite and we've just got a lot of haematite and we're picking up a lot more sulphate, 664 01:05:27,730 --> 01:05:32,140 but we've never seen magnesium sulphate and we actually have picked up mostly gypsum. 665 01:05:32,560 --> 01:05:35,520 So this looks surprisingly like the earth actually. 666 01:05:35,530 --> 01:05:41,200 It's just it doesn't look like that weird stuff that we found 15 years ago at the Opportunity Landing site. 667 01:05:42,370 --> 01:05:46,840 So these are what these what we interpret to be these lake deposits on Mars. 668 01:05:47,740 --> 01:05:54,729 You can see the scale bar here. These are centimetre scale, sort of almost rhythmic looking deposits. 669 01:05:54,730 --> 01:06:03,790 And if you compare them to to ancient lake deposits on Earth, these are from Canada and these are glacial deposits. 670 01:06:03,790 --> 01:06:07,660 This is actually a drop stone there. We haven't seen anything that looks like a drop stone. 671 01:06:08,050 --> 01:06:11,590 But the fact is, is that they're these are exactly at the same scale. 672 01:06:11,770 --> 01:06:16,420 And so it's surprising actually how similar that seems to be. 673 01:06:17,410 --> 01:06:21,040 And then this is what happens where you get this very high silica rock, 674 01:06:22,540 --> 01:06:29,799 this fabric that you see angling down through here is something created by the modern day wind eroding the rock. 675 01:06:29,800 --> 01:06:34,690 But if you look behind that, you can see very, very fine lamination in there. 676 01:06:35,020 --> 01:06:41,020 And you can also see that there are these these dense, that these what we think are voids. 677 01:06:41,020 --> 01:06:48,940 Because when you trace the surface of the rock around, there's a lip like a ski jump right here and you can see the same holes in that. 678 01:06:48,940 --> 01:06:51,550 So we think those are three dimensional features of the rock. 679 01:06:52,120 --> 01:06:57,790 And in conversations with Nic, what we're wondering is this rock is basically mostly amorphous silica, 680 01:06:58,030 --> 01:07:01,300 a little bit of crystal and silica and a lot of magnetite. 681 01:07:01,690 --> 01:07:06,579 And Nick has come up with a way to possibly make hydrogen in this reaction. 682 01:07:06,580 --> 01:07:11,020 And it could be that these these are bubbles, gas bubbles preserved in the ancient rock. 683 01:07:11,800 --> 01:07:19,600 So if that does, it's the case. In talking with Ray today, you know, hydrogen turns out to possibly have a capability to keep Mars warm. 684 01:07:20,140 --> 01:07:24,520 So maybe we're now converging on a on a solution for the early climate of Mars. 685 01:07:24,940 --> 01:07:30,190 So this is a paper that was just accepted yesterday into science by Joel Horowitz, 686 01:07:30,190 --> 01:07:37,060 who was a fellow graduate student with Nick Tasker that expects to explain how you had a link, 687 01:07:37,300 --> 01:07:41,080 but it wasn't all the same thing and it seems to have changed through time. 688 01:07:41,530 --> 01:07:48,550 And here's the rock that has this very thin lamination that looks more like a magnetite silica facies. 689 01:07:48,850 --> 01:07:53,890 And then here's a rock over here that has more of a haematite file, a silicate association. 690 01:07:54,580 --> 01:08:00,040 And I think in the interest of time, I'm not going to offer a more detailed explanation of that, 691 01:08:00,580 --> 01:08:07,060 other than to say that we think that it has something to do with mixing of ground waters with surface waters, 692 01:08:07,390 --> 01:08:15,100 possibly in the presence of of UV light that might create oxidation to generate acidity in order to explain this. 693 01:08:15,490 --> 01:08:20,740 But if you get deep enough, you don't see any of the acidity and maybe you have a more reducing environment. 694 01:08:22,450 --> 01:08:30,189 It's not really similar, but it is kind of haunting to think about the early history of the Earth. 695 01:08:30,190 --> 01:08:33,040 When we deposited a rock called Banded Iron Formation, 696 01:08:33,340 --> 01:08:39,820 where you see what's of silica fine lamination and associated with iron oxide, it's mostly haematite. 697 01:08:40,270 --> 01:08:44,770 But the fact is this is not entirely different from what we're seeing on Mars. 698 01:08:45,190 --> 01:08:49,660 And there have been a number of explanations offered for these rocks, but. 699 01:08:49,710 --> 01:08:51,330 I'll just leave you to think about that. 700 01:08:51,540 --> 01:09:02,550 And as my last slide, I think that as we look at Mars, we're really beginning to do comparative planetary Scientology and geochemistry. 701 01:09:02,850 --> 01:09:08,249 You really have to get a Ph.D. in geology and geochemistry two to take apart Mars now. 702 01:09:08,250 --> 01:09:14,670 And what you wonder is what about all the exoplanets where people are finding all these other possible habitable environments? 703 01:09:14,670 --> 01:09:17,760 And so I think that it's all all looking pretty exciting. 704 01:09:17,820 --> 01:09:18,840 So thanks for listening.