"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." "On earth," "Liquids are all around us," "Even inside of us." "But our world" "Is not like others." "When we look at the stars" "And planets of our vast cosmos," "Liquids are actually very rare." "And when we do find liquids," "They flow in strange ways," "On bizarre worlds." "It's an environment" "Where nothing that we can build" "Here on earth" "Could withstand that" "For more than" "A fraction of a second." "New discoveries are forever" "Changing what we know" "About the churning" "Bubbling matter" "Of our liquid universe." "The Universe - 4x09 October 20, 2009" "Liquids cover nearly 75%" "Of the earth's surface." "We see them oozing" "From the ground" "Or falling from the sky." "And we manipulate them" "To power our cities" "And fuel our engines." "But this is not the way" "Of most of the rest" "Of the universe." "Liquids" "Only make up a tiny fraction" "Of all matter." "Most of the universe" "Consists of gas," "Either interstellar gas," "The gas between the stars" "Or the gas" "Within the stars themselves" "Or the atmospheres of planets." "The other stuff that exists" "Is solid material." "Plants are made" "Out of solid material." "But there's really" "Very little liquid." "And it's exactly" "What is most rare" "In the universe that seems to be" "The most important." "If there were no liquids" "In the universe," "I actually doubt" "That there would be life," "At least life as we know it" "Here on earth." "Looking" "In the other planetary systems," "There may be other forms of life" "That don't use liquidity," "Fluidity in some way," "But right now" "It's difficult to imagine" "How that would work." "So where in the universe" "Do we find liquids?" "And what does it take for them" "To exist at all?" "Only in certain" "Special locations" "Where the temperatures" "And the pressures are just right" "Do you get liquids." "And one of those" "Special places" "Where the conditions" "Are just right is on titan," "Saturn's largest moon." "Titan is wrapped" "In a thick atmosphere, 50 times denser than earth's," "But underneath the hazy," "Orange sky, dimly lit" "By a distant sun" "And dominated" "By a stunning view of Saturn," "Lakes glisten." "If we had a webcam on titan" "And we were just" "Looking out on the scenery," "You could think" "You were on earth" "Unless there was a thermometer" "In the image and you saw" "That the temperature" "Was hundreds of degrees" "Below zero." "A cruel 290 degrees" "Below zero to be exact." "And the liquid isn't water" "But rather, methane." "When we think" "About the worlds" "Of our solar system," "There's only two worlds" "That have liquids" "At their surface," "Low-density flowing liquids" "That could form lakes." "And that's earth with water" "And titan with methane." "But how can something" "That's a gas on earth" "Be a liquid on titan?" "Titan is certainly" "Not quite earth." "And the biggest difference" "Is really the temperature." "Titan is so much" "Further away from the sun" "That it receives" "Very little energy" "And that makes it" "A very, very cold world." "And that means" "That the same elements" "That we have on the earth" "Behave very differently" "On titan." "You could imagine" "A scene like this on titan." "But the liquid" "That's lapping up on the shore" "Is liquid methane," "A clear liquid," "Maybe a very tiny gentle breeze" "Like the one we're" "Feeling here today" "With just tiny waves coming up" "And the whitish stuff" "That makes the shore" "Is water ice," "It's literally frozen water," "It's hard as rock." "So when we think" "Of rock and water," "On titan, think of water ice" "As the rock" "And liquid methane" "As the liquid." "Clearly," "At such a low temperature," "Liquid water" "Turns into solid ice." "But which state" "Any type of matter takes," "Liquid, solid or gas," "Has to do with how" "The individual molecules," "Its building blocks," "Are interacting." "It's a bit like" "How a flock of sheep" "Will respond differently" "To different conditions." "These sheep" "Can be thought of" "As individual atoms or molecules" "Like molecules of water." "And just like" "Molecules of water," "They can be in different states." "For example, right now" "They're, kind of," "Clustered together." "They're not moving around" "Very much." "They're penned in." "That's like solid water, ice." "In a solid, the molecules" "Are really penned in" "By their nearest neighbors." "They're not allowed" "To move much at all." "When water boils" "And steams into a vapor," "It changes phases" "From liquid to gas." "In a gas," "The constituent particles," "The atoms or molecules" "Are all wandering around" "In a, kind of, chaotic way" "And they tend to move faster" "If the temperature is higher." "And sheep wandering around" "In a wide open field" "Free to wander" "Every which way they want," "They won't necessarily" "Stay together." "They might go off" "In one direction or the other." "That's like" "A gaseous state of sheep." "They're far from one another," "But there is a lot of space" "Between them," "Their motions are unconstrained." "But liquid, like water" "Is magic." "It's a state of matter in limbo," "Somewhere between" "The rigid structures of a solid" "And the random scatter of a gas." "In a liquid," "The atoms or molecules" "Are somewhat constrained" "By their neighbors." "They might pass each other" "Up a little bit," "But they tend to flow together." "When sheep are in a flock," "Kind of, constrained" "By the herders and flowing along" "From one place to another," "That can be thought of" "As a liquid." "They can pass" "Each other up a little bit," "But they're basically" "Not wandering too far away" "From their nearest neighbors." "They're all going together." "They're all going with the flow," "So to speak." "On titan," "The frigid temperatures" "Keeps methane molecules" "Stuck together in a liquid form." "They're moving," "Like sheep in a flock." "On earth," "Methane is naturally a gas" "With its molecules" "Floating around" "Like those free-ranging sheep." "To transform it to a liquid" "So that the methane molecules" "Are like a flock," "Scientists need" "To squeeze them together" "With 300 times" "Normal surface pressure." "One of the main uses" "Of methane on earth" "Is for heating and cooking" "And so methane" "Is a great source for power," "Whether it's heat" "Or some kind of" "Propulsive power." "Liquid methane" "Is such a great source of power" "That NASA is testing it" "As a potential new rocket fuel." "Main engines," "Up and burning and lift off... currently, spacecraft" "Launch into orbit" "On the backs of fuel tanks" "Filled with liquid hydrogen." "Because it's lighter" "And denser than liquid hydrogen," "Launches burning methane" "Could be cheaper." "Like liquid hydrogen," "Liquid methane combusts readily" "Because of the presence" "Of oxygen." "But on titan," "Because the atmosphere" "Lacks oxygen," "Methane isn't flammable." "So earth has nitrogen" "And oxygen," "Titan has nitrogen and methane." "And it's curious that these" "Are the only two worlds" "In the solar system" "That have nitrogen" "As their dominant gas" "In the atmosphere." "So in that sense," "Titan is our sister world." "Oxygen would be" "A dangerous explosive gas" "On titan" "Because it's surrounded" "By methane" "The same way that methane" "Is a dangerous explosive gas" "On earth" "Because we're surrounded" "By oxygen." "On titan, the liquid methane" "Collects in pools," "Some as large" "As the Great Lakes." "The Lake country on titan" "Is the northern polar region," "Enormous number of lakes." "We see one Lake in the south." "We don't really understand" "Why all the lakes move north" "And left one behind" "In the south." "Why aren't there" "More lakes in the south?" "A recent discovery" "May have provided" "An important clue." "In August 2009," "Researchers detected" "A sudden appearance" "Of storm clouds" "Around titan's equator." "This could mean" "That liquid methane" "Mimics the water cycle on earth" "Where water evaporates" "From lakes in one area" "And then rains to form lakes" "In another." "In the desert landscapes" "Of earth," "You have occasional cloud bursts" "Where it rains very hard" "And the water rushes" "Through the dry valleys." "But the vast majority of titan" "Is, sort of, a methane desert" "And when it does rain," "It's a real cloud burst" "And you have a huge flow" "Over the surface." "So we actually think" "That in terms of the ability" "Of methane to erode and carve" "Channels and valleys on titan," "It would be very similar" "To the ability of water" "To carve valleys on the earth." "One reason lakes are pooling" "In the north" "Could be because that region" "Is experiencing" "A very long rainy season." "It takes 30 years for Saturn" "To go around the sun." "So a year on titan, 4 seasons on titan," "Takes 30 years." "Each season" "Is about seven years long." "We think that there might be," "During the spring or the fall," "You get increased rainfall," "Which means" "That whatever hemisphere" "Has that season," "Actually you have" "A lot of lakes forming." "But methane rains down" "Differently than water," "Thanks to titan's" "Thick atmosphere" "And low gravity." "Think of big drops," "Twice the size of raindrops" "On earth," "Falling at a much slower speed," "Bump, bump, bump," "But they would be freezing cold," "Very, very cold," "If they hit your skin." "But liquid methane" "Is not liquid water," "And anyone who would dare" "Dive into a methane Lake" "Would be in" "For a nasty surprise." "It's a rare find" "In our universe," "A world not earth," "That is home to a liquid." "From a distance," "Titan's methane lakes" "Seem so familiar and inviting," "But this is truly" "An alien place." "First, the temperature" "Of titan's lakes" "Is hundreds of degrees" "Below zero." "And assuming" "You could survive the cold," "Swimming in a methane Lake" "Would be a shocking experience" "For a totally unexpected reason." "The density of liquid methane" "Is much less than water," "So you would be heavy in that," "You would sink." "I weigh 200 pounds." "In water, my effective weight" "Is very close to zero." "In liquid methane," "My effective weight" "Would be 80 pounds." "So imagine trying to tread water" "In a Lake or a swimming pool" "With an 80-pound weight belt" "Tied to you." "That's gonna be hard." "That's what it'd be like" "Trying to swim" "In a Lake in titan." "Methane is so clear," "Divers might feel" "As though they were looking" "Through liquid air." "That's not the case" "In most water lakes." "But water's opacity" "Isn't just due to pollution," "It's also the result" "Of a natural characteristic" "Of water" "Which turns out to be vital" "For life on earth." "This pitcher is water." "We're familiar" "With the properties of water." "Here we have a liquid" "That looks like water," "But it's not," "This is a hydrocarbon." "This is analogous" "To the liquid methane on titan." "They look the same," "But they have very different" "Chemical properties." "To show the difference" "Between these two liquids," "I'm gonna take some crackers," "Kind of things that we eat," "Starch, sugars, salt." "I'm gonna put it in the liquids." "So now we've got crackers" "In the water." "I'm gonna take" "A set of crackers," "The same number of crackers," "I'm gonna put them" "In our liquid hydrocarbon." "Because water" "Dissolves things so well," "It is considered" "A powerful solvent." "Methane on the other hand," "Can't dissolve" "Other materials as effectively." "Look at these crackers" "Coming out." "This cracker is still as crisp" "As when we put it in." "This is not a very good solvent." "Water's dissolving power" "Comes from" "Its molecular structure." "A water molecule is h2o" "Which means" "Two hydrogens on an oxygen" "And you just think about" "The shape of the molecule," "You got your oxygen" "And two little hydrogens" "On one end." "This structure" "Means that one end" "Of the water molecule" "Has a positive charge" "And the other" "Has a negative charge." "So the little water molecules" "Are like little magnets" "Going around stirring things up," "Repelling some things," "Attracting other things." "By contrast," "Methane is a weak solvent." "Methane is a carbon" "With four hydrogens" "On all sides." "It's even, it has no polarity," "It won'treak up" "Other molecules." "Since water dissolves" "What it contacts," "It can turn itself into a rich" "And sometimes murky soup." "So here in water, organisms" "That have evolved to live" "In a rich soup like that," "They're gonna be" "Small and compact." "And that's what we see on earth." "Microorganisms are small" "And compact." "They can get their nutrients" "From the water." "But methane could" "Be an appealing liquid for" "A different kind of life form." "Imagine an organism on titan" "Looking at earth" "And seeing the liquid water." "It would just be appalled" "That anything would wanna" "Live in such a reactive," "Hot, aggressive liquid." "And it would think, "geez," ""there can't be life on earth." ""the liquid there" ""is much too difficult" "To manage."" "any alien visitors" "Might immediately be drawn" "To titan or earth" "Because liquids flow" "Right on the surface." "Over 300 million" "Trillion gallons of water" "Slosh around on earth alone." "But that might not impress" "Interstellar travelers" "Very much..." "Because none of earth's" "Seven seas are the biggest" "Or deepest oceans," "Even in our solar system." "Jupiter," "The fifth planet from the sun," "Conceals an immense" "And bizarre liquid sea" "Beneath its mysterious clouds." "Reaching this liquid" "Would require a spacecraft" "Far beyond the limits" "Of modern technology." "It would have" "To somehow withstand" "Incredible pressures" "And more importantly," "Be able to stand up" "Under temperatures" "That are much hotter" "Than the surface of the sun." "At 1,400 times" "The volume of earth," "This giant planet" "Is mostly made up" "Of hydrogen and helium gas." "But miles and miles" "Beneath those clouds," "There's a point where the weight" "Of that atmosphere" "Gets so intense," "Gas turns into liquid," "Lots and lots of liquid." "The journey to the liquid" "Begins at the outer edge" "Of Jupiter's atmosphere" "Where the air pressure" "Is close to what we experience" "On earth's surface." "Diving into Jupiter" "Would be an amazing experience." "First you'd go through" "All these upper cloud layers" "Where there's ammonia" "And methane and other compounds." "They are really colorful" "And swirly, with lots of storms." "The explosion of color" "Indicates a strange brew" "Of chemicals mixed" "In the hydrogen and helium." "There is a lot of different" "Sulfur compounds" "In the atmosphere of Jupiter." "So as you fall down" "Through the upper layers" "Of Jupiter," "You would have" "The smell of rotten eggs." "So a trip to Jupiter" "Starts off in an unpleasant way." "Just like passengers" "On a commercial jet descending" "From high altitudes," "Passengers on a space craft" "Descending into" "Jupiter's atmosphere" "Would feel pressure" "On their ears." "If you go deeper" "Into the interior of a planet," "The densities become higher," "The pressures become higher," "The gas is more compressed." "That's similar" "To what we have here over earth," "Way up in our atmosphere," "The densities and pressures" "Are low." "As you go farther down," "They increase." "After descending" "For 13,000 miles, it's dark" "Because sunlight can't penetrate" "Through so much matter." "At last, the darkness lifts." "Light," "Streaming from Jupiter's ocean," "Lies just below." "You don't splash down" "Onto this, sort of," "The liquid ocean of Jupiter" "In the same way" "That you splash down on earth." "It's much more like" "You're going through a steam" "That becomes denser and denser" "And denser" "Until it's indistinguishable" "From a very, very hot liquid." "The liquid is hydrogen." "This steamy sea, stretching" "From horizon to horizon" "Is what passes" "For the surface of Jupiter." "It may seem unthinkable," "But this liquid hydrogen ocean" "Is floating above another" "Even more bizarre liquid" "Below it." "Liquids aren't easy to find" "On worlds outside of our own." "They often take forms" "We can't imagine on earth." "And that's the case" "With Jupiter's hydrogen ocean." "Strange as it may seem," "The most abundant liquid" "In the universe" "Is liquid hydrogen." "Now in fact in some ways" "That's not so strange." "Hydrogen is by far" "The most abundant element" "In the universe." "In most places" "In the universe," "Hydrogen molecules" "Are moving randomly about," "As a gas," "Like those sheep grazing" "In open space." "But the conditions" "Inside Jupiter" "Don't let them roam so freely." "The difference" "Between the different states" "Really has to do" "With how closely the molecules" "Are crushed together," "If you will." "On earth," "We see liquids form from gases" "When we leave out a glass" "Of ice water." "As warm air comes in contact" "With the surface" "Of the cool glass," "The drop in temperature" "Saps the energy" "Of the air molecules," "Bringing them closer together" "And forming a liquid." "Temperature isn't" "The only thing that affects" "The state of matter." "Pressure also plays" "A very important role." "Pressure, as you can imagine," "Sort of, crushes." "The higher the pressure," "The more it crushes" "Molecules together" "And can take a gas" "And compress it into a liquid." "For example," "Even in interstellar space," "Where it's over 450 degrees below zero," "A glass of water" "Would just boil away." "So when you take" "That glass of liquid water" "Into space," "It's not the temperature," "It's the low pressure" "That allows all the molecules" "To fly away" "And turn the glass of water" "Into a gas." "The reverse occurs" "Inside Jupiter's" "Blast furnace interior," "Where hydrogen molecules" "Are jammed together" "By the colossal weight" "Of the atmosphere above." "If you squeeze" "The particles down," "So they're not vibrating" "Very much," "Then they tend to," "Sort of, stick to one another." "They start flowing together." "That's the liquid state." "That's why," "If liquid hydrogen were somehow" "Instantly transported to earth" "Without enough pressure" "To contain it, even a tiny bit" "Could redefine what we think of" "As a hydrogen bomb." "It wouldn't be a good idea" "To just scoop up" "A cup of the liquid hydrogen" "From Jupiter" "Because it's under" "Tremendous pressure." "It would be" "A tremendous explosive," "Much better than TNT." "It would be a total disaster." "Inside Jupiter's" "Liquid hydrogen ocean," "It's over 17,000 degrees, hotter" "Than the surface of the sun." "The bluish glow at these depths" "Signals that we've reached" "Another type of liquid." "It's still hydrogen," "But in a very special form" "Called metallic liquid hydrogen." "It's brighter" "Than the surface of the sun" "And far, far bluer" "Than the surface of the sun." "It's an environment where" "Nothing that we can build" "Here on earth" "Could withstand that" "For more than a fraction" "Of a second." "In this extreme environment," "The hydrogen molecules" "That make up Jupiter's ocean" "Start to act very strangely." "The molecules of the regular" "Liquid hydrogen ocean" "Are like those sheep" "Moving as a flock." "Or better yet," "More like what's happening" "Inside of an amusement park" "When bumper cars" "Are streaming around a rink." "So what makes a liquid" "A liquid is the ability" "Of the atoms and molecules" "To slide past each other," "The atoms are free to move" "And they jostle around" "Much like these bumper cars here" "At this bumper car rink." "They can't fly freely," "But they are changing" "Their neighbors all the time." "Inside each hydrogen atom," "Whether it's in a gas" "Or liquid form," "A single electron" "Is bound to its nucleus," "Buckled into the driver's seat" "Of its own atomic bumper car." "But at the surface of Jupiter's" "Metallic liquid hydrogen," "A depth where the pressure" "Reaches 3 million times" "What we experience" "On earth's surface," "The hydrogen molecules" "Are freaking out." "The liquid hydrogen" "Actually becomes" "Liquid metallic hydrogen." "Now what I mean by that" "Is that the liquid hydrogen" "Starts conducting electricity" "And heat really well." "Inside Jupiter's" "Metallic liquid hydrogen," "Electrons are jumping" "From molecule to molecule," "Splitting away" "From their own nucleus" "And finding another home." "They are carrying" "Electric charges efficiently" "From one place to another" "And the transport" "Of electric charges," "That's the current," "That's what allows current" "To flow." "And you sure" "Wouldn't wanna be there" "If someone were to discharge" "A big bolt of lightning" "Or something like that" "Because that electricity" "Would travel easily through" "The liquid metallic hydrogen," "Zapping you completely," "Frying you." "The closest thing" "To metallic liquid hydrogen" "On earth" "Is liquid steel." "When they pour" "The liquid steel" "Out of the cauldron," "It's glowing hot, it's flowing," "It's conducting electricity." "That's very much" "Like the interior of Jupiter" "Would be like" "If you could be down there." "Inside Jupiter," "The metallic liquid hydrogen" "Is different" "From the regular liquid hydrogen" "Because" "It's conducting electricity." "So the fact" "That the electrons" "Are able to flow freely inside" "Means that you can have" "Strong electric currents" "In the interior of Jupiter." "And whenever you have a fluid" "That has" "Strong electric currents," "Then it will create" "A magnetic field." "For over 4 million miles of space" "In each direction," "Jupiter's magnetic field" "Scoops up and deflects" "Charged particles" "That naturally course" "Through our solar system." "But the largest" "And most powerful" "Magnetic fields in the universe" "Shoot out" "From curious stellar corpses" "Known as neutron stars." "These magnetic fields" "May also be generated by liquid." "However, the interior" "Of a dead star" "Seems like the last place" "You'd expect" "To find anything flowing." "A neutron star" "Is like a big hunk" "Of neutron material," "Just packed as tight" "As it can be." "We call that matter degenerate" "Because it can't get packed" "Any tighter." "Most materials you push on them," "They get denser," "You push on them harder," "They get denser," "Not a degenerate material." "You push on it," "It's not going anywhere." "Neutron stars are roughly" "A dozen miles in diameter," "About the size of a large city." "Neutron stars are so massive" "And the mass is compressed" "Into such a tiny region" "That it basically is starting" "To warp space itself." "Visiting its surface" "Is impossible." "Anything that you could build" "Out of ordinary material" "Would be immediately flattened" "And crushed on the surface" "Of the neutron star." "Neutron stars, the gravity" "Is so high that even" "The highest mountain range" "On a neutron star" "Is just measured in," "In literally millimeters." "Could liquid possibly exist" "Inside this hostile environment?" "Surprisingly," "The answer may be yes." "Some scientists believe" "That neutron stars" "Are not solid to the core." "In fact, their interiors" "May be moving so freely," "They could be filled" "With something" "Called superfluids," "Liquids with no thickness" "Or viscosity." "Viscosity is a measure" "Of how resistant" "A fluid is to flowing." "So a low-viscosity material" "Like water flows very easily." "I mean, you can see" "How quickly it falls" "Into this bowl." "But honey on the other hand" "Is very viscous" "And it flows more slowly." "The thicker a fluid is" "Or the more viscous," "The less it flows," "The less things can move around" "In it." "A superfluid" "Has zero viscosity," "A liquid so thin," "It never stops flowing." "So in the bizarre fluid" "Inside a neutron star," "It has what we call" "A superfluid property." "And so what that means" "Is that if you start up" "Some sort of current," "You are able to start up" "A vortex inside a neutron star," "Then it will just keep going" "And going and going" "And it won't die out." "There's no viscosity that causes" "These currents to dissolve away." "Some neutron stars" "Spin like tops," "Rotating several times" "Every second." "And just like" "The liquid metallic hydrogen" "Works for Jupiter," "A superfluid interior, sloshing" "Energetic particles around," "Spawns a massive magnetic field." "Except that" "A neutron star's magnetic field" "Is millions of times" "More powerful." "Our planet has its own liquid" "Churning deep inside." "Although no one" "Has ever seen it," "Life on earth wouldn't exist without it." "Life as we know it," "Wouldn't exist" "Without liquids." "On earth," "You might think it's water" "That's most critical." "But there's another" "Earthly liquid" "That's just as vital." "1,800 miles" "Below the earth's surface" "Where it's" "A scalding 7,000 degrees," "A sea of liquid iron," "Over a thousand miles deep," "Engulfs the solid inner core" "Of our planet." "But how can scientists be sure" "What's inside the earth?" "That's exactly what Gina s." "From Danbury, Connecticut" "Wanted to..." "When she texted us," ""how do we know" ""the earth has an iron core" "If we've never seen it?"" "thanks for the question," "Gina." "It turns out that scientists" "Can often" "Infer things indirectly," "Even if they can't" "See them directly." "For example," "We know that the earth" "Has a liquid iron outer core" "And a solid iron inner core" "Because earth" "Has a big magnetic field" "And motions in this electrically" "Conducting liquid iron core" "Are what produce" "The magnetic field." "Without a magnetic field," "Life on earth's surface" "Would suffer." "If it didn't exist," "Then all these charged particles" "Coming from the sun" "And from outer space" "Would go zipping" "Through our atmosphere" "And interact with living cells," "Causing lots more" "Cancerous mutations." "Unlike at the core," "The conditions" "At the earth's surface" "Freeze iron into a solid," "So strong, we turn to it" "When we need to construct" "Tall office towers" "Or long bridges." "But in distant corners" "Of the galaxy, there are worlds" "So naturally hot and dense" "That iron is nothing more" "Than a steamy drizzle." "They're out there," "Mostly overlooked" "And misunderstood," "Too big to be planets" "And too small to be stars." "They're known as brown dwarfs." "These objects" "Are like supersized versions" "Of Jupiter, gas giants," "Except up to 75 times" "More massive." "Brown dwarfs, in a sense," "Are failed stars." "They didn't have enough mass" "Ever to produce" "Sufficiently high temperatures" "And pressures in their interior" "To ignite normal hydrogen" "And burn it for a long time." "But these objects" "Are still very hot," "And despite their names," "Not brown." "If you were right there," "It would be glowing," "Sort of, a cherry orange red," "A lot of heat coming off," "So you would get burned" "In the vicinity" "Of a brown dwarf." "These objects are so hot" "That brown dwarf clouds" "Aren't made of water vapor" "Like on earth," "But rather gaseous iron vapor." "In the interior" "Of the brown dwarf," "Where the pressures" "Are sufficiently high," "The gaseous iron" "Can condense into a liquid" "And can actually rain down" "As liquid droplets of iron." "That is really cool." "That's right." "It rains iron on brown dwarfs." "Fortunately, we don't have" "Iron rain here on earth," "But if we were to have it," "It wouldn't be" "Very pleasant at all." "There'd be" "These hot blobs of iron" "Hitting your head and cheeks" "And your arms and burning them" "And scalding them." "And plus being pretty heavy," "You know, if you get hit" "By a rapidly moving" "Droplet of iron," "That wouldn't feel very good." "Liquid iron" "Never falls on earth," "But it might be happening" "Right now" "All across the universe." "Our galaxy is really teeming" "With brown dwarfs." "There's tens of billions" "Of brown dwarfs in our galaxy," "Almost as many" "As there are actual stars." "But our galaxy" "Is also flooded" "With smaller worlds," "Rockier and cooler," "More like earth." "One of the most" "Amazing things" "That happened recently" "That we found the first planet" "That could potentially" "Have water on its surface." "The planet" "Is in a solar system" "Orbiting a star" "Named Gliese 581," "About 20 light-years from earth." "The 4th planet out, Gliese 581d," "Circles so close to its star" "That one of its years" "Lasts just 66 days." "But that's a good thing" "If we wanna find a planet" "With water on its surface" "Because Gliese 581" "Is smaller and cooler" "Than our sun." "Estimates have revealed" "Gliese 581 d" "To be 10 times more massive" "Than earth with a diameter" "That is twice as wide." "Some scientists think" "That what makes up" "That extra mass" "Could be mostly gas." "That means gliese 581 d" "Could resemble the gas giants" "Of our solar system," "Like Jupiter," "Saturn," "Uranus," "And Neptune..." "Lots of gas, very little liquid." "But others believe" "That gliese 581 d is different," "More like earth." "We think 10 times earth mass" "You can make up by just piling" "Rocky material together." "So just make it something" "That we call a super-earth." "It could be a mini Neptune too," "The jury is still out." "But it's the first one" "That could be like earth," "Just bigger." "At 10 times earth's mass," "This exoplanet may turn out" "To be a water world," "Covered in a very deep ocean." "Gliese 581 d's tight orbit" "Means its parent star's gravity" "Keeps the same side" "Of the planet facing the star." "That means" "Half of the planet" "Never goes dark." "So basically" "Whenever you look up" "At the moon," "You see the same side" "Of the moon." "That would happen to a planet" "That close to a star." "The far side of this planet" "Never feels" "The warmth of sunlight," "Leaving it" "Potentially covered in ice." "If you think about that," "There should be" "Extremely strong winds" "From the hot to the cold side." "Wind creates waves," "Even on earth" "Whenever gusts of air" "Push and pull" "At the water's surface." "If gliese 581 d" "Really is a water world," "Then there's no land" "To break up the waves." "You have waves a mile high" "And they keep going" "And keep going for miles." "So if you like surfing," "That's definitely" "Where you wanna be." "There might be a hard surface" "Underneath this super ocean," "But it's unlike anything" "We know on earth..." "It's a state of solid water" "Known as ice-7." "Instead of sheep or bumper cars," "Let's imagine water molecules" "As individual aluminum cans" "Dumped into a container." "At typical earth temperatures" "And pressures," "They interact and move together" "As a liquid." "When they freeze," "Water molecules lock together" "Into solid ice." "It's a molecular structure" "Of water" "That scientists refer to" "As ice-1." "Now ice-1," "That one that you and me," "Are actually used to," "This is just" "Because it doesn't have" "Much energy left to move" "Because it gets so cold." "The massive ocean" "Of a water world" "Would be hundreds" "And hundreds of miles deep," "Just like on earth," "The deeper the water," "The greater the pressure." "If the pressure is great enough," "Something funny happens" "To water." "It turns solid," "Into a, kind of, hot ice." "If you raise" "The pressure of a liquid," "You can generally turn it" "Into a solid" "Because you're squeezing" "The atoms and molecules" "So close together," "That they feel penned in." "They can't move" "Past one another." "They can't flow." "Higher pressures" "Can create a variety" "Of solid ices" "With internal structures," "Different from frozen ice," "Or ice-1." "The difference" "Between anything like ice-1, 2,3,4,5,6,7," "We think it goes to 10" "But it could go any further" "Is actually the pressure." "The difference between" "What we're used to in ice-1" "And the other ices is that," "On the other ices" "There are pressures" "That actually acts" "On these cans." "On a planet this big," "The water pressure" "Can reach levels," "Millions of times" "What we experience" "Anywhere on earth." "That means ice-7" "Could be forming" "Underneath the oceans" "On gliese 581 d." "Diving down there," "Water is 70% of your body," "Would actually become ice," "So probably not the best option." "So for now," "Right now, technology wise," "We probably have nothing" "That can go down and explore it." "But if we're just looking" "For liquid water," "We don't have to travel" "Outside our own solar system." "We have a neighbor" "That has more water" "Than all the oceans" "Of earth combined." "In a universe of liquids," "Jupiter's moon, Europa," "Appears to be an unlikely place" "To find some." "It's an arctic wasteland," "Sheathed in water ice," "And riddled with cracks." "It's like looking down" "On ice flows" "In the arctic or antarctic." "You see cracks" "That have been just offset" "From one another." "And suggesting that the surface" "Is, kind of, floating around" "On top of a liquid underneath." "And it's not just" "A splash of water either." "Beneath a layer of ice 60 miles thick" "Lies an ocean 60 miles deep." "That's deep," "That's a lot of drilling" "You would need to do" "If you're gonna go ice fishing" "On Europa." "Smaller than our moon" "And nearly" "Three times farther away" "From the sun," "As tiny Europa orbits," "It passes through" "Jupiter's magnetic field." "But it's another" "Mighty Jovian force" "That keeps a world" "So far from the sun" "From being frozen solid." "It gets energy" "From the gravitational" "Tug of Jupiter." "Jupiter is very massive" "And it pulls tides on Europa" "Much the way" "The moon pulls tides on earth." "Jupiter's gravity teems" "With the tugging and shoving" "Of the other satellites" "In nearby orbit" "To mash and stretch Europa." "The resulting friction" "Heats and melts" "The moon's interior." "What's left ground up" "Inside Europa is salt water." "It's mainly h2o," "Plain old water." "But dissolved in it" "Are salts and other materials" "Just like our ocean has salts" "And minerals" "And things dissolved in them." "The best analogy" "For the water on Europa" "Would be water" "From the dead sea in Israel" "Where you have a very, very high" "Concentration of salts." "Not a good place" "To get your bottled water from." "Liquids can turn up" "In the most unexpected places" "And none may be more surprising" "Than a recently" "Discovered liquid" "Nearly as old as time itself." "14 billion years ago," "The universe began" "As an infinitesimally" "Small point" "When it erupted" "In a cosmic explosion" "Known as the big bang." "It rushed outward," "Expanding and expanding," "Exotic particles and gases" "Cooling and coalescing" "Into stars," "Then solar systems and galaxies." "But let's rewind the clock" "To a time" "Just after the big bang," "Before protons and electrons" "Combined to form" "The first atoms." "So everything" "Was running into each other" "And smashing into each other," "So that what was going on" "Was that" "There wasn't enough freedom" "For the particles" "To, sort of, settle down" "And clump into the things" "That we're familiar with now." "The early universe" "Was like a featureless desert," "Burning at a temperature" "Of million billion degrees," "A random collection of particles" "Known as quarks and gluons." "Quarks and gluons" "Are the fundamental constituents" "Of the nuclei" "That make up our atoms." "Actually in the first 10 millionth of a second" "Of the lifetime of the universe," "There was a phase" "Of the universe" "Where it was all" "Quarks and gluons." "New simulations" "Of the conditions" "Of the early universe" "Have revealed" "That the individual" "Quarks and gluons" "Were not flying about randomly" "As a gas as would be expected" "In those conditions." "Instead, they were connected" "And flowing like a liquid." "A really good example" "Of this is sand." "What I have here" "Is a handful of sand" "And it's made up" "Of lots of little particles" "Which are essentially" "Like tiny rocks or stones." "But how they interact" "With each other" "Is what determines" "How lots of them move together" "To give you something" "That's much more" "Like a fluid flow" "Than it is the behavior" "Of a solid." "And so much the same thing" "Is going on" "With quarks and gluons" "In that situation" "Where they are colliding." "And that was probably" "The same sort of behavior" "That was going on" "In the very early universe." "You'll see patterns in the sand" "That look like ripples" "On the surface of a an ocean" "In response," "For example to the wind," "And responding in a way" "That's much more fluid-like" "Or liquid-like" "Than it is as a solid." "Ripples are traces" "Left behind" "By some kind of disturbance." "In a liquid state of matter," "Ripples spread easily" "Throughout the whole that ability" "To communicate disturbances" "May have some imprint" "On the ultimate fate" "Of the universe." "In that critical" "Chaotic moment" "After its creation," "The fluidity of our" "Early universe's liquid state" "Was already beginning" "To show signs of a grand future." "So there will be" "Some parts of the fluid" "That are slightly more dense" "Than other parts" "And we would be able to see" "Patterns beginning to form" "That will ultimately" "Become the structure that we see" "In the late universe." "Fluid motion is stitched" "Into the fabric" "Of space and time." "So the next time" "You sip soda through a straw," "Dive into a pool" "Or watch raindrops" "**" "Know that you are witnessing our universe when it is most alive."