Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated: 0:00 [Music] 0:06 have you ever fantasized about going somewhere special somewhere far from 0:11 crowds off the beaten track somewhere out of this world is it time to catch a 0:19 rocket to the red planet Mars is filled with mysteries volcanoes seventy-five 0:24 thousand feet tall huge canyons three thousand miles across and six miles deep all kinds of 0:30 interesting features awaiting you is some of the greatest scenery in our 0:35 solar system on a world where water once ruled then vanished into thin air we're 0:44 lost microbe empires may still survive underground we've seen the postcards and 0:51 we do wish we were there just the thought of being in this new world 0:57 casino landscape that no other person had seen before I think there are a lot of astronauts that would sign up to that 1:04 but don't be fooled nothing about going to Mars will be easy danger awaits you 1:11 on this desolate beauty and perhaps Martians too if we find on Mars evidence 1:17 of a second independent origin of life that's hugely profound because it tells us right away that life is common in the 1:24 universe Mars invaded by a robot and perhaps soon 1:30 by an earthling like you what I like to go to Mars oh and a heartbeat absolutely there was 1:37 any way for me to be going Mars I wouldn't be screwing around with robots you know I'd want to go myself 1:48 there has never been a better time to boldly go where no human has gone before 1:54 to follow in the footsteps of our robot pioneers and visit the planets of the 2:02 solar system [Music] 2:12 [Music] Mars 2:23 it's been said that the first person on Mars is alive somewhere on earth today 2:32 imagine it's you what do you need to know how might you get there and what 2:38 should you pack what are some of the must-see sites and what should you avoid 2:44 think of this as your personal travel guide to exploring the red planet Mars 2:54 has always had a mystique 3:00 it's one of the easier planets to spot in the night sky a constant dot of red 3:06 light moving through the heavens and now we know for sure that of all the 3:13 planets this red rocky one is the most similar to home 3:18 here are polar caps and sun-baked deserts giant volcanoes and mighty 3:24 canyons Mars even spins at about the same speed as Earth making a Martian day 3:31 only about 40 minutes longer than ours although it's further out from the Sun and takes twice as long to circle it the 3:39 long Martian year has identifiable seasons and what's more our two planets 3:47 share a common childhood in many ways it's a sister of the earth it was formed 3:55 at roughly the same time about 4.5 billion years ago with a little change here and there 4:02 it also was formed to the same sorts of materials bombarded by comets and 4:08 asteroids so it has the same delivery system we 4:14 have 4:21 could life have been forged in the same way on both planets when we sent the 4:30 first probes to investigate in the 1960s almost anything was possible 4:38 originally in the popular imagination we thought that Mars might be inhabited by whole civilizations building canals and 4:44 so on and then the Mariner flyby missions really painted a very grim 4:52 black and white view of Mars is being barren the pictures and data recorded by 4:58 Mariner 4 reviewed Mars to be a cold barren planet still NASA was eager to 5:11 look for signs of life in 1976 the Viking spacecraft arrives from Earth for 5:17 our first close encounter and there are still hopes of a welcoming 5:23 committee [Music] 5:32 but both Viking spacecraft send back photos of nothing but rocks and sand we 5:41 had cameras so obviously if there was a yucca plant or I was hoping there'd be a 5:46 freeway in the distance but what the main thrust of Viking was actually was some chemical laboratories and they 5:53 looked for the chemical signs of life even the dirt seems devoid of life there 6:03 was always a chance that when they were so busy looking for microbes there could be a large organism looking over their 6:08 shoulder that they completely missed but now we have enormous amount of imagery that shows nothing like a large organism 6:17 there are no cats running around there no Bisons there no palm trees it seems Mars is not the kind of planet 6:23 that gives up its secrets easily but if 6:29 you dig a little deeper you soon find that this is a world worthy of a closer 6:34 look 6:39 [Music] Mars Facts 6:45 there are some basic things you should know about Mars before leaving home 6:53 most days will be clear and sunny and cold the average temperature on Mars is 7:00 as bitter as midwinter in Antarctica at about half the diameter of the earth 7:06 Mars is a handy size but it's much less dense than Earth with about a third of 7:12 the gravity surprisingly the actual surface area is almost exactly the same 7:18 as all the dry land on Earth shrunk together without the oceans build a few 7:25 freeways and you could drive around Mars in a couple of weeks and driving around 7:45 Mars is exactly what planetary scientist Steve Squyres has been doing since 2004 7:54 not in person but via NASA's two off-road robot Rovers Spirit and 8:00 Opportunity [Music] 8:13 for all of us here on earth the snapshots sent back by these forward 8:19 Scouts are the next best thing to standing on Mars in a spacesuit we very 8:29 consciously gave these robots some human-like qualities the cameras are 8:39 about this high off the ground they're the same height as human eyes it's the 8:44 visual experience that you get from looking at the rover's pictures are in is intentionally like what you would get 8:51 if you were looking at the visor of your your helmet in a spacesuit on Mars I 8:57 really think that if you put somebody on my team who's been part of this mission 9:02 for so long down at Eagle crater or on the summit of 9:07 husband Hill you'd look around and say yeah that's about that's about right that's what I expected in the four 9:17 decades since our robots first arrived the once fuzzy ball at the end of our 9:23 telescopes has steadily focused into a red planet we can understand 9:28 and it's not a welcoming place the 9:35 problem is the atmosphere is so thin and cold that water exists only as solid ice 9:40 in the ground or vapor in the air not as a liquid on the surface you might see 9:48 some fine wispy clouds high in the sky but don't bother bringing an umbrella 9:54 the whole planet is drier than the dustiest desert on earth and there hasn't been a drop of rain here for 10:01 millions perhaps billions of years the 10:07 thing that fascinated me was that we could see valleys snaking across the 10:13 surface that had clearly been carved by flowing water so this is telling us that 10:19 in the past it was different and not only that it was different in a way that would have made it more suitable for 10:25 life than it is today and that I found truly compelling we are very convinced 10:37 that at one time was a very hospitable planet with liquid water and enough 10:42 atmosphere to sustain a climate and so now we're trying to understand 10:48 how did it change why did it change and what still might be on Mars 10:56 these are deep Martian mysteries if Mars and Earth started as sister planets did 11:03 life once festoon the Martian surface might it still be there and where did 11:11 all the atmosphere and water go solving 11:16 these puzzles has challenged our planetary explorers from the moment the first Martian postcards were sent back 11:22 to earth it's the fact that it is so much like Earth that kind of makes Mars 11:28 such a special place Mars Hill 11:38 Steve Squyres Martian Odyssey has taken him from pole to pole visiting those 11:44 places on earth that share at least some of the same characteristics they are extremely dry extremely cold or 11:52 extremely dead Death Valley is one of his favorites this is actually a really 12:00 important place it's a place we call Mars Hill we first found this place about 20 years ago in those days the 12:07 only successful landings that had taken place on Mars were the two Viking landers and they landed in places that 12:14 looked very much like this in order to 12:21 plan for the current Mars mission and to test the cameras and other equipment NASA needed a good Mars look-alike they 12:29 found it at Mars Hill to your eyes the main way in which Mars would look 12:36 different from this scene would be the color the color of the sky and the color of the rocks and the color of the soil 12:42 the colors on Mars are painted from a very narrow palette the color palette 12:51 here is based on rust rich in iron oxides the rocks and soil and the rusty 12:57 dust are always blowing around and the freeze-dried atmosphere 13:03 you won't see any blue skies in the tourist brochures for Mars instead their 13:09 amber not only do the dust particles add a rosy blush to the sky they also 13:16 scatter sunlight in a way that turns the color of the Martian sky upside down to human eyes red by day and blue at dawn 13:25 and dusk this is a sunset as seen by 13:32 spirit a cold blue Sun dropping over a distant alien horizon looking up into 13:41 the clear starry skies from the surface you would see Mars as two tiny moons Phobos and the smaller damos with all 13:50 the grace of a space potato and barely 17 miles long Phobos has been targeted 13:57 as a potential stepping-stone for the first human mission to Mars a test run 14:03 before attempting the fuel hungry and risky trip to the planet below 14:08 [Music] dreaming about Mars and actually going 14:15 there are two very different things Mars may be our neighbor but 35 million 14:22 miles to the closest point is still a very long way from home Getting to Mars 14:31 to put humans on the surface of Mars someone watched joke there are only three issues getting them there keeping 14:37 him alive while they're there and getting him back our space-age dreams of 14:44 offworld colonies on the Moon and Mars faded with the cancellation of the Apollo program and the last trip to the 14:51 lunar surface in 1972 it didn't stop us from traveling 14:57 we simply switched from astronauts to lower cost lower risk robotic explorers 15:02 and when it comes to Mars it's probably just as well 15:10 getting to Mars is just unbelievably hard we've learned that the hard way 15:17 before certainly gives you go back to the days before the rover has launched 2/3 and the missions that have been 15:23 falling to Mars had failed and they failed for all kinds of reasons rockets that blew up and and spacecraft that 15:29 just vanished it's partly without a trace in fact landing on Mars has always 15:35 been hit or miss but so has blasting off 15:41 from Earth at exactly the right time the 15:47 right time to go to Mars basically the only time to go to Mars is when Earth and Mars are properly aligned with one 15:53 another you have to wait for them to get into just the right position to go from point A to point B and you've got to be 16:00 on the launch pad ready to go when that launch window is open and if you miss your opportunity you don't get the 16:07 chance try again for 26 months for 16:14 one engine start [Music] 16:22 if you are ever lucky enough to book a flight on the first rocket to the Red Planet you'd better be sure you've packed 16:30 everything the one-way trip is at least six months with no turning back if 16:36 you've forgotten something we can go to the moon and get back in a week it takes 16:41 about three years go to Mars and come back you have to carry your food you 16:47 have to recycle your breathing oxygen and your water so it's a very very major 16:53 undertaking [Music] within about three days the earth looks 17:01 very small and within a week it's just another star and you suddenly are going 17:06 to realize you're in very deep space and it's gonna be a long time before you can go back before we take this giant leap Landing on Mars 17:18 we need to be able to carry everything needed for a three year round trip with 17:23 us this is a much larger effort than 17:29 getting to the moon it's the Apollo mission on steroids at this point we 17:35 know at least as much as the engineers knew at the time if they agreed to land on the moon 17:43 and they had only nine years so I think once the nation decides they really want 17:49 to land humans on Mars the system can be designed and developed and built 17:59 fast forward to the future after six months crossing the blackness of space 18:05 things suddenly get a lot more interesting the combination of a high 18:13 approach speed a thin atmosphere and twice the gravity of the moon makes Mars 18:18 one of the hardest places to land in the solar system even for robots you hit the 18:27 top the Martian atmosphere you go unmarked 27 times the speed of sound 18:32 and for our vehicles between when we hit the top the Martian atmosphere and when we were bouncing on the surface with the 18:38 airbags with six minutes it's a hell of a racket you use a heat shield to slow 18:46 you down to a leisurely Mach to twice the speed of sound and we threw out a supersonic parachute everything is 18:53 complex and everything has to happen precisely on time 19:00 the worst part is when you come into contact with the Martian surface there's no runway okay there's no nice place to 19:06 land and you can't control very well where you're going to come down so you're gonna come down in a field of 19:11 rocks like this how do you guarantee that you're a billion-dollar spacecraft 19:17 is actually going to survive that the approach that worked for us with our 19:23 Rovers was great big airbags bounce bounce bounce bounce bounce finally the vehicle comes to rest Vikings used 19:32 rocket motors and they just touched down gently on the surface and they were fortunate it was just good luck they 19:38 landed in a field of boulders like this but they didn't land with one that was poking through the belly and it all worked you have to be good and 19:45 you have to be lucky a safe arrival is your 19:54 passport to a dangerous new world this is a planet where the atmosphere is your 19:59 enemy and even the dust is dangerous 20:05 [Music] Exploring on Mars 20:10 want to step outside to take in the scenery or pick up some rocks as familiar as it might look beyond the 20:17 porthole Mars is dangerously alien the upside is that the low gravity will give 20:24 you super jumping abilities the down the almost complete lack of an atmosphere 20:31 this is not home there is nothing here to breathe 20:38 to find similar conditions of low temperature and pressure on earth you have to travel three times higher than a 20:45 commercial airplane to the very edge of space [Music] 20:51 planetary scientist Bob Brown shows why you should keep your helmet on when 20:57 visiting Mars we have this just a beaker full of water we're going to put it in 21:03 this little chamber and attach a vacuum 21:12 hose to the chamber and all the air out of the chamber 21:22 as the pressure drops two Martian levels the water boils at room temperature 21:30 so if you were to take your helmet off on Mars the liquid in your face especially it would start to boil 21:37 and much the same as this liquid water started to boil and I guess I don't have to describe what that might 21:42 feel like or what it might look like a medical travel advisory might say to keep your suit 21:50 tightly fitted but so far no one's built a suit that'll work on Mars existing 21:57 spacesuits are simply too bulky too heavy and too complicated to wear for 22:02 the sort of regular activity required on the unforgiving surface of Mars 22:07 [Music] 22:14 like Steve Squyres planetary scientist Chris McKay roams the remote Mars like 22:20 regions of Earth here in Australia's arid Flinders Ranges he hunts for the 22:27 extreme ways of living that we might find on Mars organisms like the bacteria 22:33 that makes the green smudge inside these white desert stones if I was trying to 22:41 do on Mars what I'm doing here the biggest problem would be a suit that I could use to go outside something we 22:48 take for granted here and we get up in the morning I put on a shirt and a pair of jeans and out I go so it's got to be 22:55 routine easy to use many times I've been working out in the field in the 23:02 Antarctic or the Arctic and I just have to take the gloves off if I'm doing something that requires that 23:07 quintessential human capability of touch and feel and whole so my request to the 23:14 engineers is give me a spacesuit with gloves that'll keep me warm and keep me 23:19 pressurized but still allow me to use my hands 23:25 not only will you want to move your fingers you'll want to move around 23:32 NASA's Lunar electric Rover is a prototype for future missions to the Moon and Mars it's part vehicle and part 23:42 spacesuit I can just picture being there and in a vehicle of this type and looking back at Earth in the distance 23:51 deciding to go a VA and being boots on the surface in ten minutes which should just be a remarkable breakthrough 23:59 astronauts can cover more ground by living in the vehicle for weeks at a time stepping outside when they want to 24:06 and back inside at the first sign of danger Mars does not have a powerful Dangers on Mars 24:15 magnetic field the way earth does so there's radiation from the Sun also cosmic rays that are gonna penetrate 24:22 through space suits an astronaut might get a 30 minute warning of an incoming 24:28 solar storm but less predictable is the risk of being hit by a meteorite recent 24:35 estimates based on fresh crater counts suggest that up to 200 new holes are 24:40 blasted into the surface of Mars each year and even the Martian moons are not 24:47 guaranteed to stay in place the days of Phobos are numbered possibly 24:55 an asteroid that once strayed too close the moon is trapped in a fatal gravitational embrace every passing 25:03 century sees it dropped six feet closer to death in about 50 million years its 25:10 fall is expected to be complete the 25:19 aftermath if anyone is around to see it could be Mars with a bright ring of moon 25:25 dust to rival Saturn's but events like 25:31 this are not your real danger it's the day-to-day exposure to the cold dry 25:38 Martian environment that will make a long stay tricky it was a hundred and 25:44 nineteen degrees Fahrenheit here yesterday really really really hot day on Mars that would get up to about 30 25:50 degrees Fahrenheit and at night it goes to more than hundred below Martian 25:55 deserts are both frozen and sun-baked with no ozone layer UV levels are so 26:02 high that any unprotected organism even a Martian microbe will be burnt to a 26:08 crisp within minutes a good hat is just not going to cut it 26:15 so why not leave all the dirty work of exploring Mars to robots one thing about 26:22 humans is that they have a capability to improvise on the spot even if you don't have the right tools 26:29 with you that robots lack in Death Valley this stuff was wet it got dry 26:35 when it dried a crack we're investigating the idea that something 26:40 similar happened on Mars you know I'd love to be able to do this on Mars and 26:45 we can't but you know human on the scene can improvise pretty well getting down 26:52 and dirty on Mars will mean exactly that moon dust caused enough problems for the 26:58 Apollo astronauts without an atmosphere to blow it around on Mars dust is going 27:04 to be a serious problem Mars is a dusty place in fact it's a lot worse than this 27:10 when you think Martian dust you shouldn't think sand it's more like cigarette smoke very very fine-grained 27:15 stuff and he gets everywhere coats everything people are gonna breathe it in it's gonna get into the habitats it's 27:21 gonna get on people's spacesuits and their clothing it's gonna be a real challenge and I think they're gonna have 27:27 to devote a lot of effort to to finding ways to deal with that dust because it's it's a it's it's horrible stuff 27:34 [Music] 27:39 when an ill wind blows on the red planet dust really does go everywhere about 27:47 once every three years local storms go global and the dust can block your view for months it happened 27:56 the very first time we sent a probe into orbit in 1971 when Mariner 9 got to the 28:03 planet there was a giant dust storm that had completely shrouded the surface from it they could see nothing nothing just 28:11 dust and as the dust started to recede all sudden these dots appeared there's 28:17 three of them lined up what the heck are those turned out to be the peaks of the three great volcanoes on Mars 28:26 and that's when we can to realize just help bury the terrain in topography of 28:31 Mars was this was the moment that Mars began to reveal itself a world with a 28:39 secret history and the spectacular scenery to match tired of the earth 28:50 scenic sites the Himalaya is not high enough the Grand Canyon too small try the red planet for 28:58 sightseeing on an enormous scale [Music] Scenery on Mars 29:05 thanks to our sharp-eyed spacecraft Mars is opening up like never before 29:12 these are real landscapes that humans will one day marvel at in person you 29:20 know if you're going to Mars you'd want to go for the scenery right I mean you're not going for the culture you're not going for the climate so you definitely want to go for the scenery 29:28 one thing that people forget is that when we've landed on Mars we have to go 29:33 to places that are safe and safe equals pretty smooth and flat there are places 29:40 where the scenery on Mars is just breathtaking [Music] 29:47 here's a bit of Mars that's anything but smooth and flat the Magnificent valleys 29:53 Marineris this titanic canyon system over two and a half thousand miles long 29:59 and six miles beep is probably the grandest geological feature in the solar 30:05 system it's clearly the red planet's must-see destination as a human being 30:11 it's the sheer gigantism of Mars that is amazing the Valles Marineris is beats 30:19 the Grand Canyon Hollow and if you've ever seen the Grand Canyon you will 30:25 never forget it it's so colossal the Grand Canyon would be easily swallowed 30:32 by one of the smaller side branches we're talking about something here that's the width the United States or of 30:38 Australia crossed here so I think the Valles Marineris would be 30:44 the place to go I mean build a lodge right on the rim so you can look in the attraction goes 30:51 beyond sheer scenic splendor deeper than the canyon itself is the mystery 30:57 surrounding its formation this giant fissure once filled by mighty 31:03 lakes has been scoured by floods of biblical proportions 31:09 you can make estimates of how much water had to have been flowing to carve these 31:14 things and you get numbers like a hundred two hundred Amazon rivers all cut loose at once big big amounts of water flowing across 31:21 the surface the other big attraction on 31:27 Mars is the largest volcano and highest mountain in the solar system Olympus 31:34 Mons towers at an astounding 17 miles three times higher than Everest its base 31:42 covers more ground than the United Kingdom and the massive caldera at its summit could easily swallow Greater 31:49 London Paris and New York so things tend to be big on Mars I think 31:55 in part that's because the planet has lower gravity and so when you pile up 32:00 lafi you can pile it three times higher because the gravity is three times less before it'll start to collapse under its 32:05 own weight [Music] Mars is a far more active world than 32:12 previously thought we see landslides of dust and gullies freshly carved by 32:18 outflows of mysterious fluid and this peculiar region has been 32:24 claimed as a flash-frozen seed complete with fossil icebergs 32:31 likewise there are glaciers geologically recent but now buried beneath a 32:37 protective blanket of dust later for the next change in climate still most of the 32:44 defining surface features of Mars were carved way back in the good old days 32:51 certainly something happened in the early history of Mars that led to great 32:57 releases of water and of course people wonder with that much water could there have been ancient oceans could there 33:03 have been environments that were very much like life environments on the early earth early Mars was a different world a 33:14 world with a thicker atmosphere with weather and water possibly a vast 33:21 shallow northern ocean this was really the time to go to Mars when you didn't 33:28 need a spacesuit perhaps just an oxygen tank and some warm clothes 33:34 when we reconstruct in our imaginations Mars of three billion years ago we tend 33:40 to make it like Earth warm and cozy and but it wasn't Mars back in its wettest 33:47 warmest phase was probably like Earth today in its coldest regions so I'm 33:54 imagining a place where the snow and ice is melting in the summer to form transient ponds and streams and 34:00 ice-covered lakes it's cold it's wet but it could be rich with life this is the 34:09 Mars that we want our astronauts to get their hands on to bring back and study 34:15 the wet Mars of old where we might find the evidence of life 34:21 [Music] [Applause] [Music] 34:28 the fourth Rock from the Sun has always had a special card to play the chance of 34:33 needing Martians and in recent years the odds of a close encounter have been 34:39 steadily improving [Music] Life on Mars 34:46 if you want to find life on Mars first you need to find water 34:53 and not all of the planets water story is ancient history there's been plenty of frozen 34:59 underground evidence detected from orbit but scientists needed to touch and taste 35:05 it to be sure in 2008 they finally got their opportunity when NASA's Phoenix 35:11 lander made a daring approach to the high Martian Arctic [Music] 35:21 there was not ever more excitement in my life than landing safely on Mars I've 35:26 been through the opposite I've been through a landing that was not successful cams I did not want that to 35:33 happen again the landing was not only 35:38 perfect but the engines exposed suspicious white patches directly underneath the spacecraft water ice was 35:46 just a few scrapes away we did find water ice and we found that the soil in 35:53 connection to it has calcium carbonate a compound that forms in the presence of 35:59 liquid water if it had been wet then we wanted to look for nutrients and food 36:04 sources that could support microbes the 36:10 water ice is proof of a valuable resource for any life-forms still clinging beneath the surface and for 36:17 future travelers we now know that these planes that you see stretching behind me 36:23 are underlying only two or three inches deep by a sheet of ice all the way as 36:29 far as you can see great hockey rink if you had a hockey team on Mars all you 36:35 need is a broom 36:41 the possibility of running into Martians received another boost from a very Mars 36:47 like part of our own planet chilles extraordinary Atacama Desert 36:54 the Atacama is special because it is just so profoundly dry speaking roughly 37:02 50 times drier than Death Valley it is deader than Death Valley it's the only 37:10 place on earth where Viking could have landed and searched for life and dirt on earth and not found it and instead found 37:16 a reactive mixture of chemicals the only place we can take a small step into Mars 37:27 we can test ourselves if we can't find the life in the dry core of the Atacama Desert we're not ready to go to Mars 37:35 perhaps we are ready because even here in the driest corner of the driest 37:41 desert on earth life has confounded scientists cyanobacteria have been found 37:48 living inside the rock-hard salt of a long-gone lake this is a halide is a 37:55 this sodium chloride salt which is colonized by cyanobacteria it's dark 38:02 green because they have this particular pigment protecting them from the excess 38:08 of UV light once in a blue moon a fleeting early-morning ground fog delivers some 38:16 rare humidity to the air above the desert this precious moisture is 38:22 greedily sucked into the microscopic pores of the water hungry rock salt this 38:29 is a very rare event so these bacteria are living in an environment where 38:36 liquid water is available a few hours during one year very very hard if we're 38:44 looking for Martian bugs we should search for life-forms at least as tough and alien as this I'm looking at Mars 38:53 from the point of view of a microbe and as a microbe I really need a very very tiny amount of water I could probably 38:59 live my entire life happily in a tiny drop of water about the size of the point of a pen now we've shown over the 39:08 years that organisms that live in salt crusts on the earth have enough sunlight 39:13 coming in so that they can go through their day-to-day activities but still be protected from the radiation and we know 39:19 their salt crusts on Mars [Music] Habitability on Mars 39:24 scientists are gathering clues about where on the Martian surface you should land to have the best chance of meeting 39:31 the neighbors [Music] 39:37 in terms of current habitability I think the most interesting place on Mars is 39:42 right where the Phoenix lander sat that 39:47 ice will be warmed when Mars just tilted toward the Sun which occurred as recently as five million years ago that 39:54 ice would have been warmed and wet maybe even swampy Mars has a long-term wobble 40:02 to its orbit and every 5 million years or so the poles end up tilting 45 40:08 degrees toward the Sun a way of thinking about the Phoenix landing site is think 40:14 about the polar regions on earth imagine you're there in winter it's very inhospitable very cold very alien you 40:21 think how can anything survive you come back six months later and it's like a different world the sun is shining it's 40:27 wet it's warm things are live and scurrying around so we may be being 40:32 misled seeing this frozen cold site and in fact we're just there at the wrong 40:38 season we know that on earth some bacteria can survive being frozen for 40:44 millions of years they can also eat perchlorate the highly reactive chemical 40:50 Phoenix found in the Martian soil presumably if there was life at the 40:56 Phoenix site it had learned the same trick and so there might be organisms that are literally eating the rocks and 41:02 reacting with perchlorate below the surface shielded from the ultraviolet light just having a great old time five 41:09 million years ago the party is over because everybody froze but another five million years the party will start up 41:15 again as the Martian summer comes to the north polar regions and the ice turns to 41:21 water the party might not be over everywhere 41:27 the gas methane has been found both by spacecraft in orbit and by telescopes 41:33 from Earth it's chemically impossible for methane to survive for long in the 41:38 Martian atmosphere so it must have been released recently now what makes methane 41:45 cows make methane it's probably not cows 41:50 microbes various sorts can release methane they're a variety of geologic 41:55 processes volcanoes can release methane so the mere fact that there's methane 42:01 doesn't say life but either way the 42:07 methane says that Mars is an active planet it's either biologically active or it's geologically active or both the 42:17 methane release appears to be seasonal and linked to areas of suspected subsurface ice ice found exposed in 42:25 fresh craters has proven that water lurks not only near the poles but also 42:31 much closer to the equator it's pretty clear that if the Viking landers had dug 42:36 just four inches deeper they would have reached this ice and perhaps a totally 42:42 different conclusion about life on the Red Planet [Music] 42:48 so if Mars has any life at all whether it is so small you can only see it with 42:54 a microscope or if they had a mammoth it wouldn't matter to me it's the whole question of is there life at all on Mars 43:04 either way there certainly will be life on Mars the moment the first human 43:11 traveler arrives 43:17 the fact that there are no scheduled flights to Mars hasn't stopped people from preparing for the trip and for a 43:25 flight like this planning is everything 43:32 [Music] in 2009 six men walked into a series of 43:40 connected rooms inside a warehouse in the Moscow suburbs and shut the door behind them for three months they took 43:48 all their food with them and drank recycled water the only communication with the outside world was electronic 43:54 with a 20-minute delay they were trying 44:00 to simulate a flight to Mars you got to think about what its gonna do to a crew 44:06 to be cooped up in a small environment but for that huge period of time they're gonna be the first people in the history 44:12 of their species to travel that great distance to be so far from home where they can't even have a normal telephone 44:17 conversation with their families of their friends so we should underestimate what psychology what psychological 44:23 problems might see there is no room to 44:30 screw up on a trip like this mental or otherwise once on Mars you are likely to 44:36 be stuck there for a year or more waiting for a window of opportunity to ride home and unlike a robot the hopes 44:44 and fears of the whole planet will be riding with you I think the humans are gonna do a better 44:51 job of exploring Mars ultimately than robots ever can robots move really 44:56 slowly okay what what Spirit and Opportunity have done in five years on Mars two astronauts could probably have 45:02 done in a week [Music] as fast and as smart as we are we still 45:12 need mechanical help to scout the course for Mars the next robot rolling on to 45:18 red dirt will be aptly named curiosity as the size of a small car and it has a 45:25 nuclear power source so you don't have to worry about dust accumulating on solar arrays or anything like that and 45:32 most importantly it has the capability to look for trace quantities of organic 45:38 molecules so we've gone beyond now looking for evidence of habitability to 45:43 actually looking for evidence of the building blocks of life whether it's 45:50 alive or dead a trip to this red planet has a lot to teach us about our lonely 45:56 blue one and the universe beyond now if you have two planets that are next to 46:02 each other in the same solar system that both had independent origins of life you 46:08 would have to conclude that the chance of having life all over the universe indeed even in other places in our solar 46:15 system would be very high I think you know you could basically go to the bank and bet on it 46:23 we're not going to Mars just to search for life we're going to Mars to search for a second genesis of life what we'd 46:30 like to find something that's different from us it doesn't have the same genetic history and genetic code that we have 46:36 and from my point of view two more alien the better now the second possibility is 46:44 that we find life on Mars but my goodness it has a genetic code exactly 46:49 like us it uses DNA it's too coincidental this is representing our 46:56 cousin's life either arose on earth and went to Mars or actually more likely 47:03 that life originated on Mars and it was transported on a meteorite or a comet to 47:09 the earth early on and in fact our home planet is Mars 47:22 so in some ways a voyage to Mars could be a voyage home our ancestors have made 47:29 such bold trips before when we walked out of Africa when we sailed over the 47:35 horizon if it's technically possible our ships 47:40 will head out again 47:47 we've always wanted to see what's over the next hill and Mars is that next over the hill sure you're gonna have to be in 47:55 a suit if you're gonna have to have a habitat but it's a solid planet it's got a surface you can see you can work you 48:01 can explore I've thought for about thirty years now that we could go to 48:07 Mars and usually when people ask me how long it would take I say fifteen years 48:12 because we've been saying fifteen years for the last about four decades Oh a 48:21 human mission to Mars can't happen soon enough for me I'm you know I'm I'm a robot guy okay that's what I do with my 48:27 career is build robots and send them to Mars but I also think that we send 48:33 things to Mars for reasons other than science our Rovers Spirit and 48:40 Opportunity were built by people who like me grew up in the 60s watching 48:46 Mercury Gemini Apollo on TV as little kids and dreaming of sending spaceships tomorrow someday and now we do and I 48:54 think as people watch the first human explorers on the surface of Mars they 48:59 are going to be similarly inspired to do things that I can't even imagine at this point it's gonna be very costly it's 49:06 going to be dangerous but I think it's something that I'd certainly like to see 49:11 happen I'd love to see boot prints in 49:17 our wheel tracks I would love to see boot prints on Mars 49:24 when the first human footprint is made on Mars it will represent more than a 49:30 giant stride into space this one small impression will be proof that humanity 49:37 is once again on the move travelers once more moving beyond our comfort zone to explore new lands and 49:44 new opportunities and have no doubt there are many worlds out there ripe for 49:53 exploration [Music]39382