"In the beginning, There was darkness," "And then, bang..." "Giving birth to an endless" "Expanding existence" "Of time, space and matter." "Every day, new discoveries" "Are unlocking the mysterious," "The mind-blowing," "The deadly secrets of a place" "We call the universe." "Where are the Martians?" "On the red planet's" "Poison-packed surface" "Or in newly found sources" "Of water?" "Did Martian life survive" "An apocalyptic attack?" "Are Martians microbial" "Or monstrous?" "At last, the answers are here" "In mars:" "The new evidence." "The Universe - 5x02 August 5, 2010" "Ibelieve" "We can send humans to orbit mars" "And return them safely to earth." "And a landing on mars" "Will follow." "whenwelandonmars ," "There may be billions" "Of Martians waiting for us." "Only they probably" "Won't look like this" "Or this," "But like this." "Microbes, bacteria evolved" "To survive on a planet," "With 1% of earth's" "Atmospheric pressure," "An arid world" "Where temperatures can plunge" "To 220 degrees below zero." "now,evenif that" "Upper-surface is so nasty," "That doesn't mean that just" "A little ways under the surface," "Wouldn't be a much happier place" "For microbial life on mars." "istherelifeonmars ?" "Just a decade ago," "My answer would have been" "Very different than it is today" "Because we've learned so much." "afewdecadesago ," "It would have seemed" "Like science fiction." "But we now know that on earth," "Some bacteria" "Cluster around thermal vents" "At the bottom of the sea;" "Others thrive in pockets" "Of liquid water" "Inside 12 feet of antarctic ice." "ourknowledge" "Of microbial life on earth" "Has increased so much" "That, I think, you know," "There's still a good chance" "That some kind of primitive life" "May have formed on mars" "And existed there at some point." "howcouldlifehavefirst" "Formed on mars?" "Maybe with a flash of lightning." "The spring of 2006." "Even as some scientists" "Are claiming mars" "Doesn't have lightning," "Earth-based microwave detectors" "Find it in friction-filled" "Storms of red dust." "butit'snotlightning" "Like we know it," "Associated with rainstorms." "Well, it doesn't rain on mars." "It's what's called" "Dry lightning." "andthisdrylightning," "Or static electricity," "Could have been the trigger" "For Martian life." "onceyouhavelightning," "You've got" "A new source of energy" "That can affect your chemistry" "And alter things" "In the atmosphere," "Even on the surface," "At some level." "afamousexperiment" "Seeking to replicate" "The creation of life on earth" "Ran an electric current" "Through a mix" "Of water and common gases," "Creating a soup," "Containing organic compounds" "And the building blocks of life:" "Amino acids." "byhittingthings," "With electrical discharges," "You could not necessarily" "Generate life," "But maybe make the preconditions" "For life." "butdiddrylightning" "Help jumpstart life on mars?" "Or did it kill the chance" "For any life at all?" "lightningonmars" "Could create things" "Like hydrogen peroxide," "Which could then lead" "To other chemicals" "That would destroy" "Organic material" "And sterilize the surface." "life-givingjumpercable" "Or fatal electric chair." "The jury is still out" "On what dust storm lightning" "Has done to mars." "well,whatalwayshappens" "With mars is about the time" "We think we understand it," "We discover new things" "That make us realize" "We still have" "A lot of mysteries to solve." "sohowdo youfindbacteria" "Too small to be seen, living" "Under the surface of a planet 48 million miles away?" "thelifethat'smostlikely" "To be prolific," "The life that you'd find" "The most number of organisms," "If they did exist," "Is the one that's hardest" "To find of all." "likeclimbers," "Scientists look for life on mars" "By making connections," "Linking this observation" "To that deduction," "Hoping the evidence" "Leads in the right direction." "And if the facts aren't there," "You start over." "it'shardto lookfor life." "So the mission designers" "Have said," "Well, let's first figure out" "If there are habitable places," "If there are places" "That would be friendly to life." "andthekeyelementforlife" "As we know it is water." "onearth,liquidwater" "Is required for life." "Even if it's a small pocket" "In the heart of a glacier," "You still need" "The fluid nature of water" "For the processes of life" "To take place." "accordingtoearly" "Space probe photos," "Mars was just a dead red rock." "Its thin atmosphere" "Was mostly carbon dioxide," "And so it seemed," "Were the polar ice caps." "youknow,in theseventies," "We might have expected" "That there was no possible" "Water or life on mars." "The picture is much" "Different today." "inthe21stcentury," "More advanced space probes" "Have revealed that a lot" "Of the earlier information" "Was wrong." "It turns out," "There's about 100 times" "As much h2o in mars' polar caps" "As in all five" "Of north America's Great Lakes." "soevenin" "The polar caps today," "There's probably enough water" "To cover the surface" "About 20, 30 feet deep." "But it's really not about" "Whether we think" "There's water on mars," "But whether there's liquid water" "On mars." "that'sthekeyquestion," "Because even microbial life" "Could not have evolved on mars" "Unless there was liquid water" "Early in the planet's history." "inorderto find" "Liquid water on mars," "We actually look" "In a whole variety of ways." "from1997through2006," "NASA's mars global surveyor" "Searches for water-based" "Minerals using" "A highly sensitive spectrometer." "everychemicalelements" "Has a particular signature" "Associated with it," "A sort of fingerprint." "And when light" "Interacts with it," "It reemits that light" "In a very specific way" "That's characteristic" "To that given element." "And so that's telling you" "What things are made of" "By just looking at the light" "They emit." "it'ssimilarto theway" "The human ear can pick out" "Specific vibrations." "somenotesboomout ." "Other notes are not so loud." "In much the same way," "Spectroscopists are interested" "In selecting out" "Those particular lines." "thesurveyorspacecraft" "Hits spectrographic paydirt:" "Hematite, a combination" "Of iron and oxygen." "Hematite shows" "That ancient mars" "Could have had flowing water" "Because the mineral" "Is also found on earth" "In environments" "That once interacted" "With liquid water." "theseroundrocksfromUtah ," "They formed in a sandstone" "By fluid water flowing" "Inside the pores of the rock" "And moving iron around" "So that the iron" "Actually c cements together" "These little spheres." "And the ones on mars are quite" "A bit smaller than these," "But they're thought to form" "The same way." "thesurveyor'smission" "Is over." "But today," "Five probes are taking pictures" "And measurements of mars." "Europe's mars express" "Circumnavigates the equator;" "NASA's mars odyssey" "And the more a recent" "Mars reconnaissance orbiter," "Or mro, soar over the poles." "Meanwhile, two robot rovers" "Explore the surface," "Seeking evidence" "Of ancient water in the rocks." "spiritisin" "A very hilly, rocky, dusty," "Rugged kind of place." "It's very sort of" "Reddish and bright" "When you see the pictures" "From that rover." "Opportunity" "On the other side of the planet" "Is in a very flat place, darker," "More kind of a chocolaty brown" "Color than a reddish color." "inthespringof2008 ," "The five probes are joined" "By a sixth." "... lift off." "NASA'sPhoenixlander." "May 25, 2008." "As anxious men and women" "On earth watch their monitors," "The Phoenix lander" "Ends a nine-month space journey," "Flaming through" "The Martian atmosphere" "At 12,500 miles an hour." "wetaughtthatbabytofly," "You know, and we give him" "All the wisdom." "And now, we have to let it go" "And do the job." "anylandingon mars" "Is incredibly difficult." "And the chaos happens" "Within six or seven minutes," "From the top of the atmosphere" "To the surface." "wecallit" "Seven minutes of terror." "that'showmuchtime" "Phoenix has" "To cut its descent speed from 12,500 miles an hour to five." "If not, mars will have" "One more impact crater." "yearsofeffort" "Is being tested, whether" "It's gonna happen or not." "theparachutedeploys," "Caught live by" "The mars reconnaissance orbiter." "thrustersslowtheplummet" "For a near-perfect landing" "Near mars' north pole." "touchdown,signaldetected." "... detected." "Phoenixwillsearch" "For frozen water" "Under the surface." "But has it already found" "More than was expected?" "A photograph" "Of one of the lander legs" "Seems to show something" "That should not be there." "There is new evidence" "That mars could once have" "Supported life." "Mineral deposits show" "That water once flowed" "On the surface." "NASA scientists look" "For evidence of water" "Wherever they can find it" "On mars." "But in the spring of 2008," "They may have found it" "In an unexpected place." "The Phoenix lander," "Newly arrived" "Near mars' north pole," "Has something strange" "On one of its legs." "Some colleagues think" "That those are water droplets" "Forming in that environment," "Which is a little curious" "Because it's very cold." "It's not at all obvious that" "Water should be stable there," "But it could be really salty," "Could be briny," "And so it has a lower" "Melting point." "That's possible." "I don't know" "What the blop of water" "On the Phoenix lander leg was" "Or the thing" "That looked like that." "Scientists are split" "And Internet blogs run wild" "With speculation." "But in the end," "It's all speculation." "The unfortunate thing is" "The data that we have" "Are really kind of fuzzy." "We're at the limit" "Of resolution." "You really wanna go up there" "And take a much better" "Picture of it," "But it may ultimately be" "A question" "That can't be answered." "Although the droplets" "On its leg" "Remain a mystery to this day," "When Phoenix's robot arm" "Digs two inches" "Under the Martian surface," "It confirms a prediction." "As it hits hard, icy soil" "Containing frozen water." "Mars odyssey predicted" "That Phoenix would land" "On icy soil" "With a little bit of dust" "On top." "Phoenix went, touched it." "We got another key part" "Of planetary science" "Which is getting "ground truth."" "while the Phoenix team" "Expected water ice," "They're surprised" "By something else" "That the lander's laser detects" "In the Martian sky:" "Snow." "Not carbon dioxide snow," "But water crystals, as on earth." "It snows on mars," "Which is indeed cool." "Phoenix saw it first dissipating" "High in the atmosphere" "And eventually, actually," "Falling to the surface" "And then sublimating" "And going back to a gas" "When the sun came back up." "It really is" "One of the first times" "We're really seeing" "The surface atmosphere" "Water cycle." "In this case, gas to solid," "Solid back to gas." "Meanwhile, roving robots" "Explore near the equator." "Spirit and opportunity" "Use high resolution imaging and" "Spectroscopy to find evidence" "Of minerals and land forms" "Shaped by water" "In mars' ancient past." "A day in the life" "Of the mars rover starts" "As the sun rises and illuminates" "The solar panels." "And that wakes up the rover." "The radio commands" "Are sent from the earth" "To tell it what to do." "This time," "Drive 10 meters forward," "And then stop" "And turn 20 degrees" "And then take a panorama" "With these colored filters" "Looking off in that direction." "Near the end of the day," "One of the NASA orbiters," "Like the mars odyssey orbiter," "Or the mars reconnaissance" "Orbiter is passing overhead" "And we know when" "That's gonna happen," "The rover will transmit data" "From that day up to that orbiter" "And then that orbiter relays it" "Back to the earth." "And while it's sleeping," "We've got those pictures" "That it just sent back" "And other data." "And now, we're trying" "To figure out what happened?" "Did it do what we're expecting" "It to do?" "Did it do something unexpected?" "Is it in" "Some dangerous situation?" "In early 2008," "Signals from spirit" "Indicate trouble." "Its right front wheel jams." "When the Phoenix team tries" "Driving the rover in reverse," "The dragging wheel gouges" "Several inches into the soil" "And hits silica." "On our own planet," "Where do we find silica?" "Well, hydrothermal environments." "Maybe that's what we're seeing" "On this other world as well." "So a lot of the excitement" "About silica" "Is because of that connection" "To our own planet." "That indicates that," "Hey, maybe those kinds" "Of environments" "Existed on mars as well." "In fact, the spirit rover" "May be parked at one right now," "Right next to" "What may have been an ancient" "Yellowstone-like hotspot." "It's a classic" "Accidental discovery," "And raises the question," "Could mars have current" "Underground thermal activity?" "Is mars still hot" "In its interior?" "It certainly is." "And there's no way that mars" "Has completely cooled off." "All the heat of its accretion," "All the heat of its formation," "Some of it is still there." "Plus," "Heat from radioactive elements." "There's definitely" "Sufficient heat inside of mars" "To make hot fluids percolate." "But there is that possibility" "Where you might find" "Liquid water" "At some depth in the crust," "Yes." "In Yellowstone" "And at hot springs" "All over earth," "Many different species" "Of bacteria feed and grow" "In the gas" "And mineral-rich waters." "Could hidden hot springs" "Be breeding grounds" "For life on mars?" "We would love to send" "Electromagnetic sounding" "Instruments to the planet" "Because they could actually" "Tell us whether there" "Is liquid in the crust" "At some depth." "That would be fantastic." "Then we'd know." "While the spirit team" "Wonders about" "Mars' underground mysteries," "The Phoenix team finds" "Another surprise on the surface." "2% of the soil" "Around the Phoenix lander" "Is composed of perchlorates," "Combinations of chlorine" "And oxygen." "The discovery of perchlorates" "On mars" "Has been fairly controversial" "Because on earth," "It's a very toxic substance." "On earth, perchlorates" "Are used as propellants" "In fireworks and rockets." "This was a surprise." "So it was a discovery." "Why is it even there?" "How is it forming?" "But the question... perchlorates" "Is a really good question" "And it's not a..." "There's no definitive answer." "Perchlorates do occur" "Naturally in places" "Like Chile's Atacama desert" "As ultraviolet radiation" "From the sun" "Transforms chlorine" "And oxygen." "On mars, many of the same" "Kinds of chemical reactions" "Might be happening" "On the surface." "We don't understand" "The details of," "Even on the earth," "Let alone on mars." "The challenge" "With perchlorates is they affect" "Some of the experiments" "That people use to look for" "Organics for carbon-based" "Molecules like you might find" "In life." "Some scientists" "Are now reconsidering" "The famous 1976 experiments" "By the viking lander." "When viking" "Went to the surface in 1976," "They found no evidence" "Whatsoever for organics." "One of the recent theories" "That's being bandied about" "Is that if you did have" "Perchlorates in the soil," "That those might have actually" "Broken down the organics" "In the same process" "You were using" "To try to detect them" "As you heated the soil up." "Perchlorates may have" "Destroyed organic materials" "In the viking experiment." "And on earth," "They're a key poison" "In many chemical runoffs." "But perchlorates" "Are also power sources" "For certain bacteria," "Bacteria actually used" "To eat toxic waste." "And in terms of life," "It's a good news," "Bad news thing." "While microbes might feed" "On the toxic soil," "It could be deadly" "For humans on mars." "We don't know" "How that perchlorate compound" "Might be changing the surface." "The surface might be" "In some kind" "Of a super-oxidated state" "That could ultimately prove" "To be, for example, corrosive" "To astronaut suits." "One thing is certain," "After five months" "Of exploration," "Phoenix's mission is threatened" "By a dust storm, sweeping across" "The Martian plains," "Burying everything in its path." "In a storm so fierce," "The Phoenix lander is doomed." "When NASA's Phoenix lander" "Digs into frozen water on mars," "It finds new evidence" "That the red planet" "Could once have harbored life." "But in the autumn of 2008," "Phoenix's own life" "Is about to end." "On mars, the wind comes along" "And whips up the dust," "Which is very, very fine-grain" "Like flower," "Extremely fine-grained material," "Whips it up into the atmosphere" "And it slowly settles out," "Blanketing everything." "Red dust" "Coats the solar panels" "Of the Phoenix lander." "Sunlight," "Its only source of power," "Can't get through." "The Phoenix lander" "Has to spend a lot of time" "Recharging its batteries" "Because we know" "That it's gonna get" "Very cold at night," "And it's going to have to run" "Those heaters at night" "To stay alive." "On November 2, 2008," "Phoenix shuts down" "For the last time." "As the Martian winter deepens," "Frozen carbon dioxide piles up" "And imprisons the probe" "In a tomb of dry ice." "But Phoenix's data" "Continues to be analyzed." "Going to mars" "And taking measurements" "On the surce," "Getting detailed data" "About the history of mars" "And mars' chemistry" "Of the surface" "Was an essential piece" "To determining for sure" "That water existed on mars." "Water is essential to life." "But according" "To the latest evidence," "It's only one of many forces" "That shaped mars." "You can kinda break down" "Our thinking of mars now" "Into maybe like four quarters" "Of a football game." "The first quarter, from about 4.6 to 3.2 billion years ago" "Is action packed." "Mars forms along" "With the other planets" "As swirling gas" "And debris combine" "And cool into a rocky world." "Then mars is bombarded" "And scarred by meteoroids." "There was a lot of cratering" "Going on." "And then towards the end" "Of that period," "There was a lot" "Of geologic features" "That suggest that" "There was water flowing" "On the surface." "That new evidence" "Includes this series of ridges," "Photographed in 2009 by NASA's" "Mars reconnaissance orbiter." "It's the first" "Definitive lakeshore" "Discovered on mars," "The remains of a Lake" "The size of north America's" "Lake Champlain." "Every piece of evidence" "About the presence" "And the history of water on mars" "Is so important to determining" "Whether we might be alone" "In the universe." "Some scientists even say" "That 3.5 billion years ago," "An ocean" "The size of the Atlantic" "Covered 1/3 of mars." "Maybe with enough time" "And enough water," "Life formed on mars as well." "As the first quarter" "Of mars' history ends," "The second starts with a bang" "As volcanoes" "Reshape the planet." "There was significant" "Volcanic activity." "Olympus Mons" "Is the biggest volcano" "In the solar system." "So we know there were big" "Volcanoes in the past." "Mars is blanketed" "With black volcanic basalt," "Like the basalt found" "Around Hawaiian volcanoes." "And the chemicals" "Released from volcanoes," "Including sulfur," "Mix with the water" "That was left" "And make things acidic," "Kind of like acid rain on earth" "And that sort of thing." "At the same time, the atmosphere" "Seems to be shrinking" "And water becoming more scarce" "And less stable on the surface." "The loss of mars' atmosphere" "Meant that liquid water" "Could no longer exist" "On its surface." "Water exists" "On the surface of the earth" "Only because of" "The atmospheric pressure" "Pushing down on it." "Whatever water is on mars" "Evaporates or freezes." "In the third quarter" "Of its history," "Mars probably begins turning red" "From ferrous oxide." "Rust in the dust." "Take a fresh volcanic rock" "In Hawaii or Iceland" "And let it sit out" "In the earth's atmosphere" "And it's gonna turn" "Red and brown over time." "It's gonna oxidize." "Same kind of thing" "Could have happened on mars." "In its final quarter," "Mars goes into a deep freeze." "From around 100 million" "Until 2 million years ago," "Large glaciers form" "And carve out new patterns" "In basins and craters." "From a warmer, wetter planet" "To a cold, dry world." "Mars in a nutshell," "According to recent evidence." "It had a thicker atmosphere." "It had water, it may have" "Had rain, it had snow." "Has all kinds of things" "That are familiar to us." "And it's just fascinating" "To think" "That we can go back in time" "With these missions" "And study an early," "Sort of earth-like mars" "That's now gone." "But while there's" "Strong evidence" "For past water on mars," "These 2009 satellite pictures" "Seemed to show" "Something impossible:" "Flowing liquid water" "On the surface." "There could be events" "When water that has been kept" "Subsurface or frozen" "Comes gushing out" "And runs down the walls" "Of these craters." "This is one of the most" "Exciting things" "In the past decade" "Is seeing those pictures" "Of the gullies," "Because when I grew up," "I was taught that there's no way" "Liquid water could be stable" "On mars today," "And this kind of flies" "In the face of the physics," "Right?" "And that's kind of exciting" "Because it means that" "We might have something wrong." "the initial announcement" "Of finding them, proposed" "That ice was melting" "Or an aquifer coming up," "There's a whole different" "Set of theories and recent study" "That it could be" "From carbon dioxide." "The dry ice going to a gas" "And then that gas" "Basically doing" "A gas lubrication of the sand" "That's flowing down." "And frankly," "It's still in the midst" "Of exploratory science" "Right now." "And some of these marks" "Have been shown" "To be dust flows." "I hope not all of them." "I'd like them to be water." "From ancient oceans" "To yesterday's flowing gully," "The search for water and life" "On mars is an ongoing quest," "A quest that like" "A climber's path" "Along an unfamiliar course" "Is filled with false starts" "And unexpected detours." "That's what happens" "When this photograph taken" "Near the Martian equator" "Reminds a lot of people of this." "Could mars once have" "Supported life?" "Mineral evidence from probes" "Like the spirit rover" "Is encouraging," "But it can be radically" "Over interpreted." "And we have to be careful" "Not to jump over a line" "That goes beyond" "What the current data," "The current experiments," "The current hypotheses" "Can support." "But it's hard as human beings" "Not to just jump over that line." "In 2008, thousands jumped" "To an incredible conclusion," "When a picture taken" "By NASA's spirit rover" "Goes viral across the Internet." "Doesn't this figure" "Look amazingly like pictures" "Supposedly taken of Bigfoot?" "Is this proof of life on mars?" "No." "It's a two-inch tall rock." "We still do not have" "Definitive evidence" "For the existence of life" "On mars, ever." "Like the 19th century canals" "And the 20th century face," "The Martian Bigfoot" "Is a 21st century" "Trick of the light." "And sometimes" "People don't know" "How to distinguish" "Between the facts" "And the science fiction." "If there is or was" "Life on mars," "It probably evolved very early" "In the planet's history," "When mars still had" "A magnetic field shielding it" "From harmful space radiation." "The evidence that mars used" "To have a magnetic field" "Lies in the crustal rocks." "Most of the crustal rocks" "Have a magnetic field frozen in" "When they solidify." "These magnetic rocks," "Scattered across the red planet," "Give mars its own version" "Of earth's northern lights" "As discovered in 2008," "Although it may not register" "As visible light to human eyes." "On earth," "When charged particles" "From the sun get trapped" "In earth's field lines," "Smack into the atmosphere," "They cause the atmosphere" "To gain energy" "And then emit a glow." "The European spacecraft" "Mars express recently detected" "Aurora on mars." "And what's actually happening" "There is that there are" "Charged particles streaming down" "Magnetic field lines" "Being made by" "Remnant magnetization" "In the crust." "But how did mars" "Lose its magnetic field?" "One theory:" "A little less" "Than four billion years ago," "As mars cools," "Its molten iron core solidifies" "And stops turning." "The motions within the core" "Weren't sufficient" "To generate an electric current" "Producing a magnetic field." "But there's also a faster" "And far more violent hypothesis." "Another more recent idea" "That's pretty controversial," "Is that mars had one or more" "Fairly large moons" "That were actually" "Captured satellites." "And those moons tidally" "Heated the interior" "And kept it molten," "Allowing currents" "To be generated and thus" "Producing magnetic field." "Now, if a half a billion years" "After mars' formation," "Those moons crashed" "Into the planet," "That could have destroyed" "The magnetic field." "For most scientists," "The pieces of the impact theory" "Don't fit." "Could satellites large enough" "To do such damage" "Lose enough inertial energy" "To be captured" "In the first place?" "This idea that mars had moons" "That crashed into it" "Within the first half" "Billion years" "Is pretty unlikely," "But it's not completely" "Impossible." "Questions about" "Mars' magnetic field" "And the search for life" "Intersect here" "In the Martian meteorite" "Alh84001." "In 1996, some scientists say" "It contains fossilized" "Martian microbes." "More scientists say" "The objects are non-biological." "All the time since then," "People have been working" "On this poor" "Little potato-sized meteorite," "Extracting" "More and more information," "But there's actually" "Some new results" "Being presented." "In April 2010, researchers" "With new radiometric tools" "Announced that earlier estimates" "Of the meteorite's age" "Are wrong." "It's actually younger" "By a half billion years" "Than we thought, roughly." "The older date" "Had placed the rock at a time" "When mars was still solidifying," "Maybe too early" "For even microbes" "To have evolved." "The new date" "Places the meteorite" "At just under 4.1 billion years old." "That, of course, is the time, 4.1 billion years ago, when," "If you thought" "Mars was habitable," "That would be the time" "You would choose, because" "We think there was water" "Flowing on the surface" "And it was warmer." "And it was a thick atmosphere." "But how can a meteorite" "From mars end up on earth?" "That's what Kristina m." "From Dallas, Texas," "Wanted to "ask the universe"" "When she texted us:" "Great question, Kristina." "We've actually found meteorites" "Here on earth" "That are undeniably from mars." "There's about 50 of them known." "Well, what we think happens" "Is that asteroids" "Occasionally slam into mars" "And throw chunks of rock" "Out into space" "And earth's gravity" "Can also pull them in." "So they land here" "And we find them." "And in this way" "We can actually study" "Pieces of mars here on earth." "In 2010, NASA announces" "That more advanced" "Electron microscopy of alh84001" "Reveals new details" "Of iron oxide crystals" "Called magnetite, a mineral" "Within its own magnetic field" "That on earth can be created" "By certain ocean-dwelling" "Bacteria." "Bacteria here on earth" "Have figured out" "How to grow magnetite crystals" "In their own bodies" "That help them to orient" "To the earth's magnetic field," "In order to help them" "Swim in the ocean" "And orient while feeding." "Are the crystals in alh84001" "Fossilized magnetite" "Created by Martian bacteria" "To help them hunt and feed" "In an ancient ocean" "When mars still had" "Its magnetic field" "More than 4 billion years ago?" "If they are fossils," "Of course," "They'd indicate that early mars" "Had fairly sophisticated life." "That's still" "Being batted about" "And bottom line is" "There's still a heck of a lot" "Of scientific work" "Being done and a lot of debate" "About mars' meteorites," "Whether there's any evidence" "Of past life in those." "But the latest" "And most compelling evidence" "Of Martian life" "Isn't in an ancient meteorite," "But on mars today," "Even though this new evidence" "Is invisible." "For years," "Scientists looking" "For life on mars" "Have followed the water," "But there may be something" "To follow" "That's even more dramatic." "Between 1999 and 2009," "Spectrographic observations" "Of mars detect a combination" "Of carbon and hydrogen" "Called methane gas." "The discovery of methane" "On mars, in mars' atmosphere," "Was a real surprise to people." "Plumes of the gas" "Seem to be coming" "From a few "hot spots"" "During the Martian summer." "The trouble is" "There shouldn't be any methane" "On mars." "On mars, even just" "The presence of methane" "Is a little bit mysterious" "Because it breaks down." "On earth," "The unstable methane molecule" "Disintegrates" "After about 300 years." "But on mars, high doses" "Of ultraviolet radiation" "And perhaps the newly discovered" "Dry lightning" "In the thin, dusty" "Martian atmosphere" "Break the methane down" "In just a few months." "And so if you see it there," "It means there must be something" "Resupplying it." "Even though" "It's being broken down," "It's getting resupplied." "Where's the Martian methane" "Coming from?" "On earth, volcanoes produce" "Vast amounts of methane." "But even though mars" "Has Olympus Mons," "The largest volcano" "In the solar system," "It hasn't erupted" "For millions of years." "So what are the other choices?" "Methane" "Can be produced underground" "When basaltic rock" "Gets turned into a mineral" "Called serpentine" "And that releases methane" "And that methane can seep up" "Through the ground" "And come out in the atmosphere." "But this process requires" "Hot liquid water" "Which hasn't yet been found" "On or within mars." "Could be volcanoes" "Which we don't know to be active" "On mars," "So that would be interesting." "It could be" "Some subsurface chemistry" "With liquid water" "Which we don't know" "To be on mars," "So it'd be interesting," "Or it could be due to biology." "on earth, 90% of methane" "Comes from bacteria" "In animals and plants." "Is the Martian methane coming" "From underground colonies" "Of bacteria?" "The discovery of methane" "On mars d to headlines" "Of us having definitively found" "Evidence for life on mars." "And entire chat rooms" "Were set up to discuss" "These various creatures," "But in fact," "Though the discovery of methane" "Is interesting," "It doesn't mean" "That we found creatures" "Wandering around on mars." "Maybe it is life." "It's an arrow to something" "And maybe the thing" "At the end of the arrow is life." "The search for the source" "Of Martian methane has become" "A priority for explorers" "And is on the mission list" "For the next rover" "To be sent to mars." "So we're looking" "At a so-called test bed version" "Of the mars" "Science laboratory rov." "And the mars science laboratory," "When it gets down" "To the surface," "Will measure methane." "So we'll know the answer" "Once that rover gets down there." "The mars science laboratory" "Dubbed "curiosity" will launch" "In the fall of 2011" "And land in 2012." "It's the size of a small car" "And will use an amazing" "New landing technique," "The sky crane." "At about 60 feet" "Above the ground," "The rover is separated" "From the descent stage" "And lowered on a line," "Which we call the bridle," "And slowly lowered to the ground" "And lowered to the ground." "When the rover's wheels" "Touch down on the ground," "The descent stage detects that." "It cuts those lines" "And then it flies away" "And it crashes safely far away" "And the rover is on the ground," "On its wheels," "Ready to go do its job." "The high-frequency radar," "Essential to" "The sky crane landing," "Is mounted to a helicopter" "And taken for a test-drive" "At California's" "Edwards air force base." "When you're coming down" "On mars," "We do a bunch of simulations" "And analysis to go ahead" "And give us bounds" "Of what we expect to see" "In terms of descent angles," "In terms of attitude rates" "On the parachute." "During the entry," "Descent, and landing," "The radar tells us" "Where the ground is" "And how fast we're going." "That information is used" "By the control system" "To control the thrusters" "To make sure we touch down" "At a nice gentle speed." "We test little pieces here" "And little pieces there," "So the first time" "That we test it for real" "Is on mars." "The key objective" "Of the mars science laboratory" "Is to search for signs" "Of ancient habitats." "And so the rover" "Will rove up to areas" "That had been soaked in water" "In the past, and it may have" "Trapped organics." "So if we find" "Those kind of layers," "We can go up" "To that kind of a rock" "And we can drill into it" "And take the material" "From inside the rock" "And tell with a lot of precision" "What the rock is composed of," "Whether there's organics" "In there." "The mars science laboratory" "Will be one more link" "In a chain of exploration" "To understand" "That bright red dot" "In the dark night sky." "Put together" "All the new evidence" "And it adds up" "To the need for more evidence." "We don't know" "How the magnetic field was lost." "We don't know exactly" "How the atmosphere was lost." "We don't know" "Where all the water went." "We don't know" "Whether the methane" "Is produced by life" "Or just regular abiotic" "Chemical reactions." "But maybe" "Questions that baffled" "The 19th and 20th centuries," "Will be answered in the 21st." "I asked five" "Other mars scientists:" "What percentage chance" "Would each of you give" "That life ever formed on mars?" "Four of us thought" "It was maybe greater" "Than 90% chance," "That there had been at some time" "And maybe now life on mars." "And two of us thought" "It was less than 15%." "And the follow-on question then" "Is, if you think that" "There's a less than 15% chance," "Is it really worth" "Going to look for it?" "And the answer was immediately," ""absolutely."" "I don't think that rovers" "And landers and orbiters" "Are gonna find life on mars." "My personal opinion," "I think it's gonna take people." "I think there will come a day" "When people go to mars digging" "And drilling and thinking" "And just going with context" "And gut feel" "And putting the pieces" "Of a very complicated puzzle together, I'm optimistic that we're gonna find evidence of past life."