Original subtitles

¶¶

Narrator: THE OCEANS DEFINE THE EARTH.

THEY'RE CRUCIAL TO LIFE.

IN FACT, WITHOUT THE OCEANS, THERE WOULD BE NO LIFE.

WE ONCE THOUGHT THEY WERE UNIQUE TO OUR PLANET.

BUT WE WERE WRONG.

WE'VE RECENTLY DISCOVERED OCEANS ALL OVER OUR SOLAR SYSTEM,

AND THEY'RE VERY SIMILAR TO OUR OWN.

IMAGINE THIS AT THE BOTTOM OF ENCELADUS' OCEAN.

Narrator: NOW, SCIENTISTS ARE GOING ON AN EPIC JOURNEY

IN SEARCH OF NEW LIFE IN PLACES

THAT NEVER SEEMED POSSIBLE.

Mormile: LIFE HAS GOT THIS AMAZING ABILITY TO, YOU KNOW,

JUST KEEP SURPRISING US.

I WANT TO GET DATA BACK FROM A PROBE AND BE ABLE TO SAY,

"IT'S LIFE, JIM, BUT NOT AS WE KNOW IT."

Narrator: THE HUNT FOR OCEANS IN SPACE

MARKS THE NEW DAWN OF AN ERA

IN THE SEARCH FOR ALIEN LIFE.

-- Captions by VITAC -- www.vitac.com

CAPTIONS PAID FOR BY DISCOVERY COMMUNICATIONS

NEARLY TWO CENTURIES AGO,

CHARLES DARWIN SET OUT ON A JOURNEY

ACROSS THE WORLD'S OCEANS

TO UNCOVER THE SECRETS OF LIFE.

WHAT HE CAME TO UNDERSTAND WAS THAT THE ANSWER

TO THE MYSTERY OF WHERE WE CAME FROM LAY BENEATH THE HULL

OF HIS SHIP, THE BEAGLE.

AS HE FILLED HIS NOTEBOOKS WITH BEAUTIFUL SKETCHES

OF THE BIRDS AND ANIMALS HE CAME ACROSS,

HE BEGAN TO FORMULATE AN IDEA

THAT LIFE MIGHT ACTUALLY HAVE STARTED IN WATER.

Lane: DARWIN'S IMPORTANT FOR THE WHOLE STORY

OF EVOLUTION OF LIFE AND NATURAL SELECTION,

WHERE WE ALL CAME FROM,

HOW LIFE ULTIMATELY STARTED AS WELL.

A LOT OF THAT GOES BACK TO DARWIN.

HE HAD IDEAS, NOT VERY WELL PUBLICIZED IDEAS,

NOT IN "THE ORIGIN OF SPECIES,"

BUT ON HOW LIFE STARTED IN A SMALL, WARM POND.

SO DARWIN HAD PUT HIS FINGER ON THE IMPORTANCE OF WATER

AND THE ORIGIN AND EVOLUTION OF LIFE VERY EARLY ON.

Narrator: WATER IS SO ESSENTIAL

THAT IT'S DICTATED WHERE SCIENTISTS LOOK

IN THE SEARCH FOR LIFE IN OUR SOLAR SYSTEM.

LIFE NEEDS WATER. YOU LOOK AT ALL LIFE-FORMS ON EARTH,

THE ONE REQUIREMENT THEY ALL HAVE IN COMMON IS WATER.

AN OCEAN MAY BE A GOOD PLACE TO INCUBATE LIFE,

AND, NOT SURPRISINGLY,

AN OCEAN HAS GOT WHAT LIFE NEEDS TO SURVIVE.

Paul: EVERYWHERE WHERE WE LOOK ON EARTH,

WHETHER IT'S FROZEN OR BOILING HOT,

WHEREVER WE FIND WATER, WE FIND LIFE.

WATER IS OUR WORKING FLUID.

YOU'RE MOSTLY MADE UP OF WATER, I'M MOSTLY MADE UP OF WATER.

Narrator: THE SEARCH CRITERIA WAS SIMPLE,

TO FIND LIFE, FIRST FIND A LIQUID OCEAN.

ONLY, BEYOND EARTH,

THERE DIDN'T SEEM TO APPEAR TO BE ANY IN OUR SOLAR SYSTEM.

Coates: THERE USED TO BE THE IDEA OF THE GOLDILOCKS ZONE,

WHERE EVERYTHING WAS JUST RIGHT

FOR WATER TO BE IN THE LIQUID STAGE

ON THE SURFACE OF A PLANET,

AND EARTH WAS SLAP-BANG IN IT.

VENUS WAS TOO CLOSE TO THE SUN,

TOO HOT REALLY FOR LIQUID WATER ON THE SURFACE.

MARS, THOUGHT TO BE A LITTLE BIT TOO FAR AWAY.

Narrator: BUT IS FINDING LIQUID WATER

AND LIFE ON MARS IMPOSSIBLE?

WE HAVE BEEN SENDING INCREASINGLY MORE COMPLEX

AND SOPHISTICATED SPACECRAFT

TO THE RED PLANET FOR DECADES,

AND WE NOW KNOW MORE ABOUT IT THAN WE EVER DID.

UNFORTUNATELY, ALL THE SCIENTIFIC EVIDENCE

GATHERED SO FAR POINTS TO MARS BEING DRY, COLD,

AND SEEMINGLY LIFELESS.

BUT HAS IT ALWAYS BEEN THAT WAY?

IT'S A QUESTION THAT'S INTRIGUED SCIENTISTS

AND ASTRONOMERS LIKE GERONIMO VILLANUEVA FOR YEARS.

IRONICALLY, THE SEARCH

FOR EVIDENCE OF AN ANCIENT MARTIAN OCEAN

IS BEING CONDUCTED FROM ONE OF THE DRIEST PLACES ON EARTH --

THE ATACAMA DESERT IN CHILE.

Villanueva: SO THERE'S A STRONG RELATIONSHIP

BETWEEN MARS AND ATACAMA BECAUSE MARS IS A VERY DRY PLACE,

AND ATACAMA IS ONE OF THE DRIEST PLACES ON THE PLANET.

ACTUALLY, THE RELATIVE HUMIDITY MEASURED

BY THE CURIOSITY ROVER ON MARS IS PRACTICALLY THE SAME

AS WE ARE RIGHT NOW HERE ON THIS DESERT.

Narrator: FITTINGLY, IT'S THAT LACK OF WATER

THAT MAKES THE ATACAMA THE PERFECT PLACE

TO BUILD ONE OF THE BIGGEST TELESCOPES IN THE WORLD,

BECAUSE WATER IN THE ATMOSPHERE HERE

WOULD DRASTICALLY LIMIT THE TELESCOPE'S ABILITY

TO FIND WATER ANYWHERE ELSE.

Villanueva: WATER AND MANY OTHER THINGS

LIKE ORGANICS ARE WHAT WE'RE LOOKING FOR.

SO WE COME TO A PLACE WHICH DEVOID OF THOSE THINGS,

LIKE A DESERT.

SO WE DON'T GET THE CONTAMINATION FROM THOSE THINGS

WHEN WE OBSERVE FOR THE ATMOSPHERE.

SO WHEN YOU COME TO A PLACE LIKE THIS, YOU'RE LOOKING FOR --

YOU'RE TRYING TO LOOK THROUGH THE WATER IN OUR OWN ATMOSPHERE.

Narrator: WHAT'S IMMEDIATELY OBVIOUS TO ANYONE

WITH EVEN AN ORDINARY TELESCOPE

IS THAT THERE IS WATER ON MARS,

BUT TODAY, IT'S FROZEN SOLID AT THE POLES.

YET THE MARTIAN LANDSCAPE LOOKS STRANGELY

AS THOUGH IT WAS CARVED AND SHAPED BY LIQUID WATER.

Villanueva: PLANETS SHOW ALL THIS MORPHOLOGY,

GEOMORPHOLOGY DRIVEN BY WATER -- A HUGE AMOUNT OF WATER.

SO THE ESTIMATES OF HOW MUCH WAS ON THE PLANET

VARY A LOT BECAUSE WE DIDN'T KNOW.

I MEAN, WE SEE ALL THIS CARVING, ALL THESE BIG VALLEYS.

AND SO HOW MUCH WATER WAS THERE WAS A BIG QUESTION.

Narrator: ANSWERING THAT QUESTION WAS PRETTY MUCH IMPOSSIBLE

UNTIL SCIENTISTS GOT LUCKY IN 1984 IN ANOTHER DESERT,

THIS TIME IN THE COLDEST PLACE ON EARTH --

ANTARCTICA.

HERE, THEY FOUND A REMARKABLE METEORITE.

ANALYSIS CONFIRMED IT WAS MARTIAN IN ORIGIN

AND THAT THEY HAD DISCOVERED THE KEY

THAT WOULD UNLOCK THE MYSTERY OF MARS' WATERY PAST.

SO ONCE WE IDENTIFY WHEN IN THE HISTORY OF OUR SOLAR SYSTEM

WHERE IT CAME, THEN SAY,

"OKAY, THIS ROCK IS DATED THERE AND IT COMES FROM MARS."

SO YOU HAVE A GOOD REFERENCE POINT

IN TIME AND IN PLACE OF THAT ROCK.

Narrator: CAREFUL ANALYSIS REVEALED

THAT THIS METEORITE WAS 4.5 BILLION YEARS OLD.

THE METEORITE ALSO CARRIED CRUCIAL CHEMICAL INFORMATION,

AN ISOTOPIC SIGNATURE FIXED BY THE AMOUNT OF WATER ON MARS

4.5 BILLION YEARS AGO.

ON ITS OWN, THIS SIGNATURE WAS WORTHLESS.

BUT BY MEASURING THE AMOUNT OF WATER ON MARS TODAY,

THEN COMPARING THE SIGNATURES OF RECENT ROCKS

AGAINST THE ANCIENT METEORITE,

ALL WOULD BE REVEALED.

AND THAT'S WHERE THE HUGE TELESCOPE COMES IN.

IT'S SO POWERFUL,

IT CAN DETECT WATER MOLECULES ON THE SURFACE OF THE PLANET.

ARMED WITH A PRECISE MEASUREMENT

OF THE AMOUNT OF WATER ON MARS TODAY,

GERONIMO WAS ABLE TO MAKE AN ASTONISHING CALCULATION.

Villanueva: WE EXTRAPOLATED BACK IN TIME,

AND WE INFER THAT THERE WAS

ALMOST SEVEN TIMES MORE WATER THAN IS RIGHT NOW.

WHAT HAPPENED, MARS -- TOPOGRAPHICALLY SPEAKING --

HAS VERY LOW PLAINS IN THE NORTH

AND VERY HIGH-ALTITUDE PLAINS ON THE SOUTH.

SO IF YOU FLOW WATER,

IT WILL TEND TO FLOW INTO THE LOWER TOPOGRAPHY,

WHICH IS GONNA BE THE NORTHERN PLAINS.

SO ONE OF THE THINGS WE DID IS, OKAY,

SO WE HAD THIS BODY OF WATER,

AND SO WHAT DO WE DO WITH THIS?

SO ONE TRICK, WE SAID,

"OKAY, LET'S JUST THROW IT ON THE PLANET,

AND LET'S SEE WHERE IT FALLS."

AND I JUST DID, LIKE,

YOU KNOW, FOLLOW THE RIVERS AND EVERYTHING,

AND IT FORMED AN OCEAN

ON THE NORTHERN PLAINS OF THE PLANET.

¶¶

Narrator: 4.5 BILLION YEARS AGO,

A MARTIAN OCEAN COVERED 19% OF THE PLANET

AND WAS AS DEEP AS THE MEDITERRANEAN.

IN FACT, NASA'S PLANETARY MODELS

REVEAL A MARS AT ITS WARMEST,

COMPLETE WITH AN EARTH-LIKE ATMOSPHERE.

IF YOU WERE IN AN ALIEN SPACE CRAFT

RANDOMLY COMING TO EARTH, THE CHANCES

ARE BETTER THAN EVEN THAT YOU'RE GONNA END UP IN WATER.

SO BRING A BOAT.

AND IT WAS THE SAME ON EARLY MARS.

AND THAT'S A FUNDAMENTAL POINT,

THAT MARS WAS A WATER WORLD.

IT WOULD HAVE BEEN BETTER

TO CHARACTERIZE IT AS A WATER WORLD.

WHEREAS NOW, OF COURSE, IT'S A DESERT WORLD.

BUT IT'S THAT WATER WORLD THAT'S INTERESTING.

THAT'S THE WORLD THAT MAY HAVE HAD LIFE,

AND THAT'S THE WORLD WE WANT TO INVESTIGATE.

Narrator: IT EVEN HAD WAVES.

THE REDUCED GRAVITY ON MARS

MEANT THAT THESE WAVES

WOULD HAVE BEEN TWICE AS TALL AS THOSE ON EARTH,

A SURFER'S PARADISE.

BUT ACCORDING TO NASA'S SCIENTISTS,

MOST OF THE TIME,

YOU'D HAVE TO BE PRETTY TOUGH TO CATCH A MARTIAN WAVE.

McKay: IF WE THINK BACK TO EARLY MARS,

WE WOULD EXPECT IT TO BE AN EARTH-LIKE ENVIRONMENT --

IF IT HAD WATER AND A THICKER ATMOSPHERE AND WAS WARMER.

THE ONE BIG DIFFERENCE, I THINK,

WOULD BE THAT IT WOULD BE MORE LIKE THE ARCTIC OCEAN.

IT WOULD BE AN ICE-CHOKED, ICE-COVERED OCEAN.

SO IF YOU IMAGINE STANDING ON THE NORTH SHORE OF GREENLAND

LOOKING OUT AT THE ICE PACKS MOVING,

I THINK YOU GET A GOOD IMAGINATION

OF WHAT EARLY MARS MIGHT HAVE LOOKED LIKE.

Narrator: IT MAY HAVE BEEN COLD.

MARS IS MUCH FURTHER AWAY FROM THE SUN THAN THE EARTH.

BUT 4.5 BILLION YEARS AGO,

LIFE ON MARS WOULD HAVE BEEN TECHNICALLY POSSIBLE.

THIS IS THE TIME WHEN MARS WAS THE MOST HABITABLE TIME.

THIS IS WHEN IT WAS FORMED,

ACTUALLY PLANET EARTH AND MARS WERE SIMILAR IN SOME ASPECTS.

IT HAD A THICKER ATMOSPHERE, MAYBE IT WAS A BIG OCEAN THERE.

SO HABITABILITY OF THE TWO PLANETS WERE SIMILAR.

AND, INTERESTINGLY,

THE TIME THAT WE THINK THIS OCEAN WAS THERE

WAS A TIME THAT LIFE STARTED ON OUR PLANET.

SO, YOU KNOW, IF THE CONDITIONS WERE FAVORABLE FOR LIFE HERE,

TO START LIFE, YOU KNOW,

WHAT COULD BE THE CONDITIONS ON THE PLANET MARS?

Narrator: SADLY, HOWEVER HABITABLE THAT EARLY OCEAN WAS,

IT DIDN'T LAST.

SCIENTISTS THINK THAT THE EARLY MARTIAN ATMOSPHERE

WAS VULNERABLE TO SOLAR RADIATION,

AND OVER THE COURSE OF 1.5 BILLION YEARS,

IT EVAPORATED AWAY,

LEAVING JUST 13% FROZEN AT THE POLES.

BUT IF MARTIAN LIFE WAS THEORETICALLY POSSIBLE

IN THAT OCEAN MILLIONS OF YEARS AGO,

IS IT POSSIBLE THAT ANYTHING COULD HAVE SURVIVED UNTIL NOW?

I THINK THE POSSIBILITY OF FINDING LIFE ON MARS NOW

TRACES DIRECTLY TO THE POSSIBILITY

OF FINDING LIQUID WATER ON MARS THAT'S RELATIVELY FRESH.

Narrator: AND FINDING WATER HAS BEEN A LARGE PART

OF THE CURIOSITY ROVER'S MISSION.

CURIOSITY HAS BEEN ROLLING AROUND MARS SINCE 2012,

AND THE IMAGES IT'S BEEN SENDING BACK HAVE BEEN STUNNING.

SEQUENCES LIKE THIS BLUE SUNSET

ARE STARTING TO CHANGE OUR UNDERSTANDING OF THE PLANET.

BUT IT'S THE PICTURES FROM THE MARS RECONNAISSANCE ORBITER

OF A REGION CALLED THE NEWTON CRATER

THAT ARE HELPING TO SHED NEW LIGHT ON THE AMOUNT

OF LIQUID WATER LEFT ON MARS.

THIS IS A TIME-LAPSE SEQUENCE SHOWING STREAKS

ON THE CRATER WALL APPARENTLY GROWING AND GETTING DARKER.

SCIENTISTS THINK THAT THEY MIGHT BE CAUSED BY WATER.

SMALL AMOUNTS OF WATER,

COMPARED TO AN OCEAN ON EARTH

OR EVEN AN OCEAN ON EARLY MARS ARE INSIGNIFICANT.

BUT AS AN INDICTOR OF MARS STILL BEING ACTIVE

AND STILL HAVING LIQUID PHASES

AND MAYBE A HINT OF BIGGER AND BETTER THINGS ELSEWHERE,

THEN I THINK IT'S VERY IMPORTANT.

Narrator: WHAT APPEARS TO BE HAPPENING

IS THAT THE MOISTURE IN THE SOIL

IS EVAPORATING DURING THE RELATIVE WARMTH OF THE DAY

AND CONDENSING BACK AT NIGHT WHEN IT'S COLDER.

McKay: SO MARS STILL HAVE A HEARTBEAT, IT'S A FAINT ONE,

IF WE MEASURE ITS HEARTBEAT IN TERMS OF PRESENCE OF WATER.

AT ONE TIME, IT WAS HUGE. IT WAS AN OCEAN.

AND NOW THERE'S JUST A FAINT GLIMMER OF IT.

Narrator: THE PROBLEM IS THAT THESE SMALL AMOUNTS OF WATER

ARE EXCEPTIONALLY SALTY.

THE CURIOSITY ROVER

HAS IDENTIFIED IN THE MARTIAN SOIL

A SALT CALLED CALCIUM PERCHLORATE.

IT'S THIS SALT THAT ABSORBS THE MARTIAN DEW

AS IT CONDENSES ONTO THE COLD SURFACE EACH DAY.

THE SALT ALSO LOWERS THE WATER'S FREEZING POINT,

KEEPING IT A LIQUID EVEN AT SUBZERO TEMPERATURES.

BUT IT ALSO MAKES THESE FAINT TRACES OF BRINE SO CONCENTRATED,

THEY WOULD BE TOXIC TO CONVENTIONAL LIFE-FORMS.

SO COULD THEY SUPPORT LIFE ON MARS?

¶¶

THERE MAY BE CLUES IN THE SALTIEST PARTS OF THE EARTH

LIKE THE BONNEVILLE SALT FLATS IN UTAH.

IT'S FAMOUS FOR LAND-SPEED RECORDS,

BUT IT'S FASCINATING FOR ASTROBIOLOGISTS

BECAUSE THE SALTY SURFACE HERE

NOT ONLY MIMICS THAT FOUND ON MARS --

IT ALSO CONTAINS LIFE.

Mormile: EVEN THOUGH THIS LOOKS DEAD,

WE COULD PROBABLY TAKE SOME OF THESE CRYSTALS RIGHT HERE

AND GET BACK BACTERIA TO GROW.

I KNOW IT SEEMS RIDICULOUS,

BUT, YOU KNOW, AS A MICROBIOLOGIST,

ONE OF THE THINGS THAT WE'VE COME TO APPRECIATE

IS IF THERE'S ANY LIQUID WATER PRESENT,

YOU'RE TYPICALLY GOING TO FIND LIFE.

SO LIFE HAS GOT THIS AMAZING ABILITY TO, YOU KNOW,

JUST KEEP SURPRISING US.

Narrator: UNFORTUNATELY,

MARS IS WAY COLDER THAN THE BONNEVILLE SALT FLATS.

THE AVERAGE TEMPERATURE OF MINUS 58 FAHRENHEIT

IS A HUGE CHALLENGE FOR ANYTHING

LIVING ON THE SURFACE OF THE RED PLANET.

AND IT'S PARTLY TO DO WITH THE ANGLE OF ITS AXIS.

EARTH SPINS ON AN AXIS OF 23 DEGREES,

WHICH SHOULD MAKE THE PLANET UNSTABLE,

BUT IT ISN'T.

EARTH'S AXIS IS STABILIZED BY THE MOON,

SORT OF LIKE AN OUTRIGGER --

A GRAVITATIONAL OUTRIGGER THAT KEEPS THE EARTH STABLE.

MARS DOESN'T HAVE A LARGE MOON,

AND IT'S ALSO CLOSER TO JUPITER.

AS A RESULT, ITS AXIS WOBBLES SIGNIFICANTLY --

MUCH, MUCH MORE THAN EARTH'S.

MORE THAN DOUBLE THE WOBBLE OF EARTH.

Narrator: OVER 100,000 YEARS,

MARS' TILT WOBBLES

BY AS MUCH AS 10 DEGREES,

CAUSING HUGE CLIMATE CHANGE --

SIMILAR, BUT MORE EXTREME THAN THE EARTH'S ICE AGES.

AT THE PEAKS OF THAT CYCLE,

THE SURFACE OF MARS

IS BRIEFLY WARM ENOUGH TO SUPPORT LIFE.

BUT TO SURVIVE 100,000 YEARS

OF COLD BETWEEN THESE PEAKS

WOULD DEMAND A STRATEGY OF EXTREME HIBERNATION.

BUT FOR MICRO-ORGANISMS,

THIS STRATEGY OF LIVING WHEN IT'S WARM

AND THEN SLEEPING WHEN IT'S FREEZING COLD IS A GOOD ONE.

THOSE ORGANISMS CAN BE FROZEN AND THAWED

WITHOUT ANY DAMAGE AT ALL.

EVERY ONCE IN A WHILE, WHEN THE TILT IS RIGHT,

YOU GET A FEW THOUSAND YEARS OF TIME TO HAVE A GO AT IT,

AND THEN YOU GO BACK TO DEEP-FREEZE SLEEP.

Narrator: THAT ALL SOUNDS FINE IN THEORY,

BUT COULD ANY LIVING THING

POSSIBLY HIBERNATE FOR UP TO 100,000 YEARS?

THE ANSWER LIES IN THE SALT.

THE SALT CRYSTALS FORM IN CUBES.

AND AS THEY FORM,

YOU'LL HAVE POCKETS OF LIQUID

THAT BECOME ENTRAPPED AS THE SOLID SALT IS FORMING.

AND THE MICROORGANISMS THAT ARE PRESENT

BECOME TRAPPED IN THOSE FLUID INCLUSIONS,

THOSE LITTLE POCKETS OF FLUID.

Narrator: HOW LONG, THEN,

COULD A SINGLE BACTERIA SURVIVE TRAPPED IN A SALT CRYSTAL?

MELANIE TOOK A CRYSTAL DATED AT 97,000 YEARS OLD

AND DRILLED INTO ITS CORE.

SHE EXTRACTED THE FLUID,

PLACED IT IN A NUTRIENT-RICH DISH,

AND WALKED AWAY.

WHEN SHE CAME BACK A WEEK LATER,

SOMETHING ASTONISHING HAD HAPPENED...

...97,000-YEAR-OLD BACTERIA WERE FLOURISHING IN THE DISH.

IT WAS PRETTY AMAZING,

YOU KNOW, TO BE ABLE TO HAVE SUCH STRONG EVIDENCE.

I MEAN, TAKING THAT FLUID INCLUSION UP

AND USING IT TO INOCULATE A MEDIA, YOU KNOW,

AND THEN HAVING SOMETHING TO GROW,

THAT'S PRETTY -- PRETTY POWERFUL STUFF.

Narrator: SO RIGHT HERE ON EARTH,

THESE BACTERIA HAVE DEVELOPED

A HIBERNATION STRATEGY EXTREME ENOUGH TO COPE

WITH THE LENGTH OF THE MARTIAN ICE AGE.

BUT EVEN AT ITS WARMEST,

MARS IS MUCH COLDER THAN THE BONNEVILLE SALT FLATS.

EXTREME ENDURANCE ALONE WOULDN'T BE ENOUGH.

SO IS THERE ANY LIFE-FORM

CAPABLE OF HIBERNATING THROUGH EXTREME COLD?

¶¶

Narrator: THIS DOESN'T LOOK LIKE THE PLACE

TO ANSWER THE QUESTION WHAT LIFE-FORMS

MIGHT BE ABLE TO HIBERNATE THROUGH EXTREME COLD.

BUT BIOLOGISTS CARL JOHANNSON AND BYRON ADAMS AREN'T HERE

JUST TO DRINK IN THE OBVIOUS BEAUTY

OF THE BRIDAL VEIL FALLS IN UTAH.

WHAT WE WANT TO TRY AND TARGET IS THAT BASE THERE

WHERE THE UPPER FALLS IS KIND OF FALLING DOWN,

JUST RIGHT BELOW THE MAIN PART OF THE FALLS.

YOU CAN SEE ALL THE MOSS BEDS THAT ARE IN THERE.

THAT'S ALL YOU. YOU GET IN THERE.

-YEAH. -THAT'S NICE AND SLICK.

-[ CHUCKLES ] -OKAY.

-THAT WILL BE GOOD STUFF. -ALL RIGHT, LET'S GO.

ALL RIGHT, MAN.

Narrator: THEY'RE LOOKING FOR A CREATURE

WITH AN UNUSUAL ABILITY,

ONE THAT MIGHT PROVE CRUCIAL

IN THE SEARCH FOR ALIEN LIFE.

NOT SURPRISINGLY, IT LOVES WATER,

AND THERE'S PLENTY OF THAT HERE.

NOW, THIS LOOKS GOOD.

HERE'S A GOOD WAY AROUND THIS WAY, I THINK.

IT'S A GOOD SPOT.

WATCH YOUR STEP, MAN. IT'S SLIPPERY, BRO.

YEAH, THIS LOOKS REALLY GOOD HERE, MAN.

YO, CARL, BAG ME, BRO!

Narrator: THIS CREATURE IS SO SMALL

THAT IT'S ALMOST IMPOSSIBLE TO SEE WITH THE NAKED EYE.

BEING SMALL DOESN'T MEAN ITS INSIGNIFICANT,

IT JUST MEANS THEY HAVE TO COLLECT LOTS OF VERY DAMP MOSS

TO MAKE SURE THEY WRANGLE ONE.

BAG 'EM AND TAG 'EM.

IT'S GOT HER.

DUDE, I'M TAKING IT RIGHT HERE, BRO!

IT'S LIKE RAINING ON ME.

I KNOW IT. THAT'S WHY I GOT OUT.

Narrator: IT'S ONLY WHEN THEY GET BACK TO THEIR LAB

AT BRIGHAM YOUNG UNIVERSITY

THAT THEY CAN SEE WHAT THEY'VE GOT.

Johannson: SO WHEN WE LOOK AT THE SLIDE

THE BYRON BROUGHT US AND WE START LOOKING THROUGH,

WE CAN SEE SOME MOVEMENT RIGHT HERE OF AN ANIMAL.

THIS IS THE TARDIGRADE.

TARDIGRADE MEANS --

IT'S THE LATIN NAME -- SLOW STEPPER.

"TARDI" MEANS SLOW, AND "GRADE" REFERS TO FOOT.

AND YOU CAN START TO SEE HE'S GOT LONG,

THIN FILAMENTS COMING OFF HIS BODY AND SOME ACTUAL --

THEY ALMOST LOOK LIKE HORNS COMING OFF HIS HEAD

THAT HE USES IN FEEDING.

Narrator: TARDIGRADES ARE AQUATIC,

SO YOU'D EXPECT THEM TO DIE IF THEY WEREN'T IN WATER.

BUT THEY HAVE A VERY SPECIAL ABILITY.

Adams: AS THAT SAMPLE JAR STARTS TO DRY OUT,

AS THAT SPECIMEN STARTS TO DRY OUT,

WHAT'S COOL ABOUT THESE GUYS

IS THEY CAN SURVIVE THAT EXTREME DESICCATION.

DRYING DOWN TO, LIKE, A CRISPY, LITTLE BOOGER.

IT'S CALLED A TUN.

THEY ROLL UP INTO A SPECIAL TIGHT BALL, ESSENTIALLY --

LIKE A ROLY-POLY BUG ALMOST.

AND THEN GO THROUGH A SERIES OF RADICAL CHEMICAL CHANGES

IN THE CELLS IN THEIR BODIES TO DEAL WITH THIS LOSS OF WATER.

Narrator: IT LOOKS LIKE IT'S DEAD.

BUT WHEN THEY ADD WATER, IT SPRINGS BACK TO LIFE.

AS WELL AS SURVIVING EXTREME COLD,

TARDIGRADES HAVE ANOTHER TRICK UP THEIR SLEEVE.

IN 2007,

THE EUROPEAN SPACE AGENCY SENT A SAMPLE OF TARDIGRADES

UP TO THE INTERNATIONAL SPACE STATION

FOR AN ASTONISHING EXPERIMENT.

TOOK THEM INTO SPACE, PUT THEM ON A SATELLITE,

OPENED UP THE DOOR, SET THEM OUTSIDE,

EXPOSED THEM TO EXTREME TEMPERATURES,

VACUUM, RIGHT? HOT, COLD.

HUGE RADIATION. AND THEN WHEN THEY BROUGHT THEM BACK TO EARTH,

THEY DID WHAT YOU'RE SEEING HERE,

THEY DUMPED SOME WATER ON THEM TO SEE

IF THEY ACTUALLY REANIMATED.

-WHAT HAPPENED? -VOILà!

[ LAUGHTER ]

THEY TAKE THE WATER UP, MAN,

AND THEY START RIGHT -- THEY SWAP OUT THE MOLECULES

AND LIKE A MACHINE, MAN.

-YEAH. -YOU ADD THE WATER TO IT,

THEY TAKE 'EM UP, CELLS START TO DO THEIR THING AGAIN.

AND THEY COME BACK ALIVE. IT'S ALWAYS BLOWS MY --

LOOK, I'M AN OLD, FAT DUDE,

AND I'VE LOOKED AT THESE A HUNDRED TIMES,

THOUSANDS OF TIMES -- MILLIONS, MAYBE.

-YOU'RE NOT THAT OLD. [ LAUGHS ] -WELL...

AND THEN, WHEN I ACTUALLY LOOK AT THEM UNDER THE MICROSCOPE,

EVERY SINGLE TIME, I'M LIKE, "DANG, THAT'S COOL, MAN."

YEAH. YEAH.

Narrator: SO THE REMARKABLE TARDIGRADE

CAN SURVIVE THE EXTREMES OF SPACE

AND THE KILLING COLD OF ANTARCTICA --

CONDITIONS SIMILAR TO MODERN-DAY MARS.

AND, OF COURSE, LIFE CAN ALSO SURVIVE

FOR TENS OF THOUSANDS OF YEARS LOCKED AWAY IN A SALT CRYSTAL.

SO THERE COULD POSSIBLY BE LIFE ON MARS.

IT USED TO HAVE AN OCEAN,

AND THERE MIGHT STILL BE TRACES OF THAT OCEAN LEFT TODAY.

BUT WHAT ABOUT THE REST OF OUR SOLAR SYSTEM?

¶¶

Narrator: FROM THE EARLY 1960s,

SCIENTISTS HAVE BEEN SENDING PROBES

OUT INTO THE FURTHEST REACHES OF OUR SOLAR SYSTEM,

LOOKING, IN PART, FOR LIQUID WATER,

BUT EVERYTHING APPEARED LARGELY FROZEN, DRY, AND LIFELESS.

MOST OF OUR SOLAR SYSTEM WAS COLDER THAN ANYWHERE ON EARTH,

EVEN THE ICY WASTES OF THE HIGH ATACAMA DESERT.

BUT IN THESE REMOTE MOUNTAINS,

SCIENTISTS HAVE UNCOVERED TANTALIZING CLUES

THAT COULD HELP ANSWER THE QUESTION,

"ARE EARTH'S RICH AND FLOURISHING OCEANS

UNIQUE OR UBIQUITOUS?"

AND THE VOYAGER PROBE LAUNCHED BY NASA

IN 1977 POINTED THE WAY.

IN 1980, IT PHOTOGRAPHED

A SMALL MOON OF SATURN CALLED ENCELADUS.

IT'S TINY, ABOUT THE SAME SIZE

AS THE UNITED KINGDOM,

AND AT FIRST, IT LOOKED INSIGNIFICANT.

Hand: ENCELADUS IS THIS BIZARRE LITTLE MOON

THAT THE VOYAGER SPACECRAFT TOOK A FEW SNAPSHOTS OF.

THE SURFACE COULD BE SEEN TO BE CRATERED IN THE NORTH,

A LOT OF CRATERS ON ITS ICY SURFACE.

NOW, TO A PLANETARY SCIENTIST AND ASTRONOMER,

THAT MEANS OLD ICE.

BUT IN THE SOUTH, AND IN PARTICULAR,

DOWN NEAR THE SOUTH POLE,

WHAT WAS SEEN WAS A FRESH ICE SURFACE,

VERY FEW CRATERS.

Narrator: IF THE ICE WAS FRESH, THEN WHERE HAD IT COME FROM?

SCIENTISTS HAD TO WAIT FOR YEARS BEFORE THEY GOT AN ANSWER.

AND IT WAS PROVIDED BY THE CASSINI PROBE,

WHICH SPAN PASSED ENCELADUS IN 2005.

AND WHAT CASSINI SAW SHOCKED SCIENTISTS --

PLUMES OF WATER VAPOR POURING OUT FROM THE SURFACE

OF THE LITTLE MOON'S SOUTH POLE.

SO WHEN CASSINI RETURNED THESE IMAGES OF THE PLUMES,

THE COMMUNITY JUST WENT NUTS.

THIS WAS ASTOUNDING TO SEE THESE JETS OF WATER

ERUPTING OUT OF THIS BIZARRE LITTLE MOON.

ENCELADUS IS JUST 500 KILOMETERS IN DIAMETER.

THAT'S ABOUT THE WIDTH OF THE UNITED KINGDOM.

AND TO SEE THESE JETS ERUPTING, IT WAS PHENOMENAL.

Narrator: AS CASSINI GOT CLOSER TO ENCELADUS,

IT REVEALED THE PLUMES WERE SPEWING NOT JUST FROM ONE CRACK,

BUT FROM FOUR HUGE FRACTURES

IN THE ICE.

EACH OF THEM WAS ABOUT 81 MILES LONG,

ONE AND A HALF MILES WIDE,

AND ABOUT 1,600 FEET DEEP

WITH WATER VAPOR POURING OUT OF THEM.

THAT AMOUNT OF WATER COULD ONLY MEAN ONE THING --

ENCELADUS HAD TO HAVE A LIQUID OCEAN

BENEATH ITS FROZEN SURFACE.

BUT THIS DARK SUBTERRANEAN OCEAN

WOULD BE LACKING IN SOMETHING

THAT'S CRUCIAL FOR LIFE ON EARTH.

LIFE AS WE KNOW IT NEEDS NOT ONLY LIQUID WATER,

IT ALSO REQUIRES THE ELEMENTAL BUILDING BLOCKS FOR LIFE --

THE CARBON, THE HYDROGEN, THE OXYGEN,

A SMATTERING OF THE ELEMENTS ACROSS THE PERIODIC TABLE.

AND LIFE REQUIRES SOME FORM OF ENERGY.

Narrator: IN THE DARKNESS OF ENCELADUS' HIDDEN OCEANS,

THERE COULD BE NO PHOTOSYNTHESIS TO CAPTURE THE SUN'S ENERGY.

YET THE POSSIBILITY OF FINDING LIFE THERE

ISN'T ENTIRELY HOPELESS.

THIS IS EL TATIO.

IT'S A MASSIVE GEYSER FIELD.

IT SITS OVER 2.5 MILES ABOVE SEA LEVEL,

HIGH IN THE ATACAMA DESERT,

AND IT'S A FLURRY OF HYDROTHERMAL ACTIVITY.

AND THERE'S SOMETHING BUBBLING UP HERE

THAT MAKES THE PROSPECT OF LIFE ON THE DISTANT MOON

OF ENCELADUS JUST A LITTLE MORE FEASIBLE.

WELL, THE CLUE IS WHAT WE FIND HERE ON EARTH.

IF WE LOOK ALONGSIDE OF THIS GEYSER,

WE SEE THESE GEYSER PEARLS.

THIS IS SILICA -- SiO2 --

THAT HAS SINTERED OUT OF THIS GEYSER WATER.

AND THE COSMIC DUST ANALYZER

ON THE CASSINI SPACECRAFT

HAS CAPTURED GRAINS LIKE THIS,

EXCEPT MUCH, MUCH SMALLER.

AND THE FACT THAT THOSE GRAINS ARE FOUND

IN THE PLUME OF ENCELADUS

LEADS US BACK TO THE WATER-ROCK INTERACTION,

WHERE THAT SILICA IN THE PLUMES OF ENCELADUS COULD ONLY BE THERE

IF THE OCEAN OF ENCELADUS

IS CYCLING WITH AN ACTIVE, ROCKY,

POTENTIALLY HOT SEA FLOOR.

Narrator: CASSINI'S MEASUREMENTS INDICATED

THAT DEEP IN THE OCEANS OF ENCELADUS,

A PROCESS VERY SIMILAR TO THE GEYSERS

OF EL TATIO MUST BE UNDER WAY.

Lane: IF YOU SIMPLY REMOVE THE WATER AND HAD DRY SURFACES,

EVERYTHING WOULD REMAIN STUCK IN ITS PLACE ON THE SURFACE,

AND THERE'D BE NO MOVEMENT TO BRING THINGS TOGETHER TO REACT.

SO I SUPPOSE WATER IS THE UNIVERSAL LUBRICANT

THAT MAKES THINGS HAPPEN.

Narrator: AND THE EVIDENCE FOR THAT CAN BE FOUND

THROUGHOUT THIS SEEMINGLY INHOSPITABLE ENVIRONMENT.

AT THE MOST BASIC LEVEL, BIOLOGY IS A LAYER ON GEOLOGY.

BIOLOGY IS HARNESSING SOME OF THE STORED CHEMICAL ENERGY

THAT EXISTS IN CHEMICALLY RICH WATERS INTERACTING WITH ROCKS.

AND RIGHT HERE, WE'VE GOT A BEAUTIFUL EXAMPLE

OF EXACTLY THAT KIND OF BIOLOGY BEING A LAYER ON GEOLOGY.

EVERYTHING THAT YOU SEE HERE, THE RED THAT YOU SEE,

THOSE ARE MICROBES UTILIZING THE RICH CHEMISTRY

OF THE GEYSER WATER.

Narrator: THE PRESENCE OF THESE EXTREME LIFE-FORMS THRIVING

IN ALMOST ALIEN CHEMISTRIES RAISES REAL HOPE FOR SCIENTISTS,

NOT JUST IN THE SEARCH FOR LIFE,

BUT IN ANSWERING ONE OF BIOLOGY'S

MOST FUNDAMENTAL QUESTIONS.

IS THERE A SECOND INDEPENDENT ORIGIN OF LIFE

ELSEWHERE WITHIN OUR OWN SOLAR SYSTEM?

AND IF THERE IS, THEN THAT TELLS US

THAT LIFE ARISES WHEREVER THE CONDITIONS ARE RIGHT

AND WE LIVE IN A BIOLOGICAL UNIVERSE.

IF WE DON'T FIND LIFE WITHIN THESE WORLDS,

THEN THAT MAY BE AN INDICATION THAT THE ORIGIN OF LIFE IS HARD

AND THAT LIFE IS QUITE RARE

WITHIN OUR SOLAR SYSTEM AND BEYOND.

BOTH OUTCOMES ARE EQUALLY PROFOUND.

¶¶

Narrator: IS THERE REALLY ONLY ONE WAY TO COOK UP LIFE?

COULD LIFE FORM FROM A DIFFERENT SET OF INGREDIENTS?

SCIENCE FICTION WRITERS

HAVE SPECULATED WILDLY ABOUT ALTERNATIVE LIFE-FORMS,

BUT IN THE COLD, HARD WORLD OF SCIENCE,

WE ONLY HAVE PROOF OF LIFE AS WE KNOW IT.

BUT IF AN OCEAN REALLY IS CRITICAL,

DOES IT HAVE TO BE AN OCEAN OF WATER?

THAT'S A QUESTION THAT DRIVES NASA'S CHRIS McKAY.

McKay: WHAT I'M REALLY INTERESTED IN FINDING

IS WHAT I CALL A SECOND GENESIS OF LIFE.

ORGANISMS THAT ARE CLEARLY NOT RELATED TO ANY LIFE ON EARTH.

ALL LIFE ON EARTH IS RELATED TO ITSELF,

FORMS A SINGLE TREE.

YOU CAN CALL THAT LIFE ONE.

WHAT I'M LOOKING FOR IS LIFE TWO --

SOMETHING THAT'S NOT RELATED.

IT DOESN'T HAVE TO BE PROFOUNDLY DIFFERENT,

BUT IT HAS TO BE DIFFERENT ENOUGH

THAT WE CAN SAY WITH VERY HIGH CONFIDENCE

THAT THEY ARE NOT RELATED TO US,

WE DO NOT HAVE A COMMON ANCESTOR.

Narrator: WHERE SUCH A LIFE-FORM COULD FEASIBLY EMERGE

WAS ANYONE'S GUESS.

UNTIL IN 2005,

THE WORLD'S ATTENTION TURNED TO TITAN,

THE BIGGEST OF THE MOONS WHICH ORBIT AROUND SATURN.

AT THAT TIME, ALL WE KNEW OF IT WAS

THAT IT LOOKED GASSY, ORANGE,

AND LIFELESS.

WE KNEW THAT TITAN WAS A FUZZ BALL FROM TELESCOPES.

BEFORE A SPACECRAFT EVER WENT TO TITAN,

JUST LOOKING AT TITAN WITH A TELESCOPE,

WE COULD TELL THAT IT HAD A THICK ATMOSPHERE.

WE DIDN'T KNOW THE COMPOSITION OF THE ATMOSPHERE

OR THE TEMPERATURE OF IT,

BUT WE KNEW IT HAD A THICK ATMOSPHERE.

Narrator: BUT THEN IN 2005,

THE CASSINI-HUYGENS PROBE PASSED BY,

REVEALING A SURFACE THAT WAS UNEXPECTEDLY EARTHLIKE.

IT WAS DOTTED WITH HUGE BODIES OF WATER,

BEARING AN UNCANNY GEOGRAPHICAL SIMILARITY

TO THE GREAT LAKES.

FROM A PHYSICAL POINT OF VIEW,

THE PRESENCE OF LIQUID

CREATES ALL THESE OTHER SIMILARITIES.

AND SO WE REALIZED THAT LIQUID ON EARTH, LIQUID ON TITAN,

WE'RE GONNA EXPECT A LOT OF COMMONALITY, AND WE SEE IT.

AND SO, VISUALLY, WHEN WE LOOK AT THESE IMAGES OF LAKES,

WE SEE REFLECTIONS OF WHAT WE SEE IN AIRPLANES

WHEN WE LOOK DOWN AS WE FLY OVER THE GREAT LAKES.

Narrator: THERE WAS ONE CRUCIAL DIFFERENCE, THOUGH --

THESE WEREN'T LAKES OF WATER. THEY WERE LAKES OF METHANE.

AND AT MINUS 292 FAHRENHEIT,

THEY'RE TOO COLD FOR ANY LIFE-FORM

WITH AN EARTH-LIKE CHEMISTRY.

McKay: I WOULD CONTEND THAT WE DON'T UNDERSTAND THE ROLE

OF TEMPERATURE DIRECTLY IN LIFE.

NOW, ON EARTH, OF COURSE,

WE'RE USED TO LIVING IN A HIGH-TEMPERATURE LIQUID

AT HIGH TEMPERATURE. WE'RE IN THE FAST LANE.

WE METABOLIZE VERY RAPIDLY

BECAUSE WE'RE LIVING AT HIGH TEMPERATURE.

WELL, ON TITAN, THE LIQUID THAT'S THERE IS COLD,

THE TEMPERATURES ARE COLD.

IF THERE'S LIFE THERE, IT'S OBVIOUSLY IN THE SLOW LANE.

IT'S METABOLIZING VERY SLOWLY, BUT SO WHAT? WHAT'S THE RUSH?

THERE'S NOT AN ABSOLUTE TEMPO THAT LIFE MUST KEEP TO.

Narrator: BUT IS THAT POSSIBLE?

CAN YOU HAVE LIFE USING METHANE RATHER THAN WATER?

WITH THIS IN MIND,

SCIENTISTS AT THE PICTURESQUE AND VERY WATERY

CORNELL UNIVERSITY IN NEW YORK

ARE TRYING TO ESTABLISH WHETHER METHANE-BASED LIFE

IS EVEN THEORETICALLY POSSIBLE.

THEY TOOK THE CHEMICAL INGREDIENTS THAT EXIST ON TITAN

AND MIXED THEM UP...

...NOT IN A TEST TUBE, BUT INSIDE A COMPUTER.

THE COMPUTER BUILT A THREE-DIMENSIONAL MEMBRANE,

THE OUTSIDE WALL OF A CELL.

EXCEPT THIS ALIEN MEMBRANE FUNCTIONS IN METHANE, NOT WATER.

Clancy: IT'S NOT LIFE YET. IT'S JUST A HOUSE.

BUT THE VERY FIRST THING THAT YOU HAVE TO DO

IS YOU HAVE TO HAVE SOMEWHERE TO SHELTER.

AND A MEMBRANE IS A WAY

OF KEEPING THE OUTSIDE TO THE OUTSIDE.

Narrator: A SMALL STEP, BUT THIS WAS GROUND-BREAKING SCIENCE.

FOR THE FIRST TIME, IT OPENED UP THE POSSIBILITY

THAT THERE COULD BE A SECOND TREE OF LIFE.

Clancy: WE TEND TO THINK THAT LIFE WOULD LOOK LIKE US.

YOU JUST HAVE TO LOOK AT THE "STAR TREK" MOVIES.

ALL THE ALIENS KIND OF LOOK LIKE INSECTS

AND THINGS THAT WE ALREADY KNOW.

BUT WHY NOT BE SOMETHING COMPLETELY DIFFERENT,

SOMETHING THAT WE CAN'T IMAGINE,

SOMETHING PERFECTLY SUITED TO THE CONDITIONS

THAT ARE ON TITAN?

Narrator: BUT IF THIS EXTRAORDINARY COMPUTER MODEL

IS RIGHT, HOW WOULD WE KNOW?

RIGHT NOW, WE CAN'T PHYSICALLY SEARCH FOR LIFE ON TITAN,

BUT THAT DOESN'T MEAN THERE WOULDN'T BE OTHER TELLTALE SIGNS

THAT WE CAN DETECT.

¶¶

Narrator: IN 2005, ASTRONAUTS FINALLY HAD AN OPPORTUNITY

TO TEST THE HYPOTHESES THAT HYDROGEN IS THE KEY TO LIFE

WHEN THE CASSINI SPACECRAFT SENT DOWN A PROBE CALLED HUYGENS

TO LAND ON TITAN.

THE PICTURES THE PROBE SENT BACK WERE STUNNING.

UNFORTUNATELY, THERE WERE NO OBVIOUS SIGNS OF LIFE,

BUT HUYGENS WAS DOING MORE THAN TAKING IMAGES OF TITAN.

IT WAS MAKING DETAILED MEASUREMENTS

OF THE MYSTERIOUS ATMOSPHERE.

AS IT TURNED OUT,

THE MOST IMPORTANT WERE THE READINGS IT TOOK

OF HYDROGEN LEVELS AS IT FLOATED DOWN FROM SPACE TO THE SURFACE.

AS THE PROBE LANDED, SCIENTISTS NOTICED SOMETHING REMARKABLE.

THE HYDROGEN LEVELS DROPPED ABRUPTLY.

McKay: WHEN I HEARD ABOUT THIS RESULT,

FOR A COUPLE MINUTES, I WAS ECSTATIC, THINKING,

"OH, MY GOD, THIS IS -- THIS IS JUST TEXTBOOK SCIENCE."

PREDICTION, CONFIRMATION, YOU KNOW,

NOBEL PRIZE COMES NEXT, RIGHT?

BUT REALITY SET IN SOON AFTER

AS I LOOKED AT THE PAPER IN DETAIL AND CONSIDERED,

YOU KNOW, HOW EASY IT IS TO JUMP TO THE ANSWER YOU WANT.

IT'S REALLY A QUESTION OF EXCLUDING OTHER POSSIBILITIES.

Narrator: ON ITS OWN, HUYGENS' SENSATIONAL MEASUREMENT

WAS INCONCLUSIVE.

WHAT THEY NEEDED WAS VERIFICATION.

SO NASA PUT TOGETHER A TEAM

OF THEIR BEST AND BRIGHTEST ENGINEERS

TO DESIGN A SPACECRAFT CAPABLE OF EXPLORING THE UNIQUE

AND TECHNICALLY CHALLENGING OCEANS OF THIS LIQUID WORLD.

AND AFTER A NUMBER OF FALSE STARTS AND DEAD ENDS,

THEY CAME UP WITH THIS --

A SUBMARINE.

I WAS READING "TWENTY THOUSAND LEAGUES UNDER THE SEA,"

AND THOUGHT, YOU KNOW,

"TITAN HAS THESE WONDERFUL GROUPS OF SEAS.

WHAT'S UNDERNEATH THERE?"

IF WE DON'T LOOK THERE, WE REALLY HAVEN'T SEEN

WHAT'S GOING ON ON TITAN.

SO WE CAME UP WITH A FAIRLY LONG SUBMARINE.

YOU KNOW, AS YOU SEE FROM TERRESTRIAL SUBMARINES,

THEY'RE USUALLY

ABOUT 10:1 DIMENSIONS OF LENGTH TO THE DIAMETER.

AND THE REASON FOR THIS IS IT REALLY REDUCES YOUR DRAG.

WE ARE, OBVIOUSLY, A LITTLE POWER-LIMITED.

WE HAVE A LOT OF COMMUNICATIONS TO DO,

WE HAVE FOUR THRUSTERS IN THE BACK HERE

USING ELECTRICAL ENERGY.

SO WE WENT WITH A VERY LONG SUBMARINE.

IF YOU CAN GET BELOW THE SURFACE OF THE SEA

AND GET ALL THE WAY DOWN TO THE BOTTOM IN CERTAIN AREAS

AND ACTUALLY TOUCH THE SILT THAT'S ON THE BOTTOM

AND SAMPLE IT AND LEARN WHAT THAT'S MADE OF,

IT WILL TELL YOU SO MUCH ABOUT THE ENVIRONMENT THAT YOU'RE IN.

BUT IF YOU HAVE A BOAT THAT JUST DRIVES ON THE SURFACE,

FIGURING OUT HOW TO GET A PROBE ALL THE WAY DOWN TO THE BOTTOM,

GET THAT SAMPLE ALL THE WAY BACK UP TO THE SURFACE AND SAMPLE IT

REALLY BECOMES AN INTRACTABLE PROBLEM.

THERE'S SO MANY THING THAT COULD GO WRONG DOING THAT.

AND, INSTEAD, WE SAID,

"IF WE CAN ENCAPSULATE EVERYTHING TOGETHER

IN A SUBMARINE,

THEN WE COULD GO RIGHT DOWN AND DO THAT SAMPLING

AND COME ALL THE WAY BACK UP TO THE SURFACE."

Narrator: BUT SAILING A LARGE ONE-TUB SUB

AROUND TITAN'S SUPER-COLD,

METHANE-RICH SEAS ISN'T WITHOUT ITS PROBLEMS.

FORTUNATELY, NASA HAS THE TECHNOLOGY

TO REPLICATE CONDITIONS ON THE FREEZING MOON,

AND THIS IS IT.

INSIDE THIS HUGE TANK,

SCIENTISTS CAN SAFELY AND ACCURATELY MIX UP

THE HIGHLY VOLATILE COCKTAIL OF CHEMICALS

THAT MAKE UP THE ATMOSPHERE OF THE HUGE MOON.

Hartwig: AS WE DESIGN AND BUILD THE CRAFT,

WE CAN BASICALLY USE THIS FACILITY TO TEST PROBLEMS

OR ISSUES THAT COME UP FOR THE SUBMARINE.

SO WE CAN USE THIS FACILITY

TO BASICALLY CREATE THE SEAS OF TITAN,

THE COLDNESS OF TITAN, THE PRESSURES OF TITAN.

Narrator: THEY HAVE DISCOVERED THAT ONE OF THE BIGGEST PROBLEMS

OF TITAN'S METHANE SEAS IS THAT THEY'RE RICH IN NITROGEN,

AND THAT COULD MAKE IT VERY DIFFICULT TO MANEUVER.

Paul: THERE COULD BE SO MUCH NITROGEN DISSOLVED IN THE SEA

THAT WHEN THE PROPELLERS TURN IN OUR JETS,

IT MIGHT JUST MAKE A LOT OF BUBBLES

AND NOT BE ABLE TO PUSH AGAINST THE LIQUID.

SO WE'RE DOING ANALYSIS NOW AND WE HOPE TO DO SOME TESTING

IN THE NEAR FUTURE THAT SHOWS US WHAT HAPPENS

IF YOU SPIN A PROPELLER IN LIQUID METHANE,

IN LIQUID ETHANE WITH LOTS OF NITROGEN DISSOLVED IN IT,

AND CAN YOU GET ANY THRUST OUT OR NOT?

THIS IS A REALLY IMPORTANT QUESTION TO ANSWER.

THERE'S OTHER WAYS TO PROPEL THE SUBMARINE IF THAT DOESN'T WORK,

BUT THE DESIGN THAT WE CAME UP WITH

HELPS US GET TO THAT SIMPLE PLACE

IN TERMS OF SPACE OPERATIONS.

[ PINGING ]

Narrator: THE SUB WILL BE PACKED FULL OF SCIENTIFIC INSTRUMENTS

AND TEEMING WITH CAMERAS.

BUT THERE'S ONE THING THE SCIENTISTS FEEL

WILL MAKE THE MISSION MORE THAN ANYTHING ELSE.

Paul: THAT FIRST PICTURE. ARE YOU KIDDING?

THAT FIRST PICTURE FROM A SUBMARINE,

FROM ANYBODY'S SUBMARINE ON THE SURFACE OF A SEA

ON ANOTHER PLANET IN OUR SOLAR SYSTEM CHANGES THE WORLD.

I MEAN, THAT'S SOMETHING

THAT NONE OF US HAVE EVER SEEN BEFORE.

THAT IS TRUE DISCOVERY.

THAT IS WHY WE DO ANY OF THIS.

AND THAT WOULD BE AWESOME -- THAT FIRST PICTURE ALONE

WOULD MAKE THIS ENTIRE MISSION WORTH IT.

[ PINGING ]

Narrator: SCIENTISTS AREN'T SAYING

THAT THE CAMERAS OF THE TITAN SUB

WILL DEFINITELY PING BACK PICTURES OF LIVING ORGANISMS,

BUT THEY BELIEVE SENDING A SUB TO THIS STRANGE MOON

GIVES THEM THE BEST CHANCE

OF FINDING A NEW FORM OF LIFE.

McKay: I GREW UP WHEN "STAR TREK" WAS JUST COMING OUT,

AND IT WAS AN INSPIRATION TO ME.

BUT THE KEY MOMENT WAS WHEN I REALIZED THAT THE JOB I WANTED

WAS NOT KIRK'S JOB, BUT SPOCK'S JOB.

HE'S THE ONE WITH THE TRICORDER.

HE'S THE ONE THAT'S DETECTING LIFE.

AND MY FAVORITE SAYING IS,

"IT'S LIFE, JIM, BUT NOT AS WE KNOW IT."

THAT'S WHAT I WANT TO BE ABLE TO SAY.

I WANT TO GET DATA BACK FROM A PROBE --

TITAN, MARS, ENCELADUS, WHEREVER --

AND BE ABLE TO SAY,

"IT'S LIFE, JIM, BUT NOT AS WE KNOW IT."

Narrator: WE USED TO THINK THAT THE REST OF OUR SOLAR SYSTEM

WAS FROZEN AND DEAD,

BUT WE NOW KNOW THAT THERE ARE OCEANS OF WATER AND LIQUID

IN PLACES WE NEVER THOUGHT POSSIBLE.

IN 2015, THE NEW HORIZON MISSION TO PLUTO

CHECKED OFF THE LAST OF THE GREAT WORLDS

TO BE EXPLORED IN THE SOLAR SYSTEM.

BUT WE'RE ONLY AT THE BEGINNING OF THE QUEST

TO FIND THE HOLY GRAIL OF SPACE SCIENCE --

LIFE.

WE'RE THROUGH WITH THE AGE OF DISCOVERY.

WE'VE DISCOVERED ALL THE PLANETS,

WE KNOW WHAT'S THERE.

WE'VE GOT A ROUGH MAP OF THEM ALL

AND A ROUGH UNDERSTANDING OF HOW THEY WORK.

THE NEXT QUESTION -- THE QUESTION THAT I THINK

SHOULD MOTIVATE AND GUIDE PLANETARY SCIENCE

FOR THE NEXT 20 YEARS IS,

IS THERE ANY LIFE IN THESE VARIOUS AND DIVERSE OCEANS?

Narrator: NEARLY TWO CENTURIES AGO,

CHARLES DARWIN SET OUT ON A VOYAGE OF DISCOVERY

THAT CHANGED THE WORLD.

PERHAPS NASA'S TITAN SUBMARINE WILL BE A MODERN COUNTERPART

OF DARWIN'S SHIP, THE BEAGLE.

AND IN THE SEARCH FOR A NEW FORM OF LIFE,

WILL BOLDLY GO WHERE NO ONE HAS GONE BEFORE.