Narrator: ACROSS THE WORLD, ASTRONOMERS ARE LOCKED IN A RACE.
THEY WANT TO BE THE FIRST TO DISCOVER A MOON
OUTSIDE OUR SOLAR SYSTEM -- A SO-CALLED EXOMOON.
BUT THERE'S A PROBLEM -- THEY CAN'T FIND ANY.
Oluseyi: WHAT'S WEIRD ABOUT THIS IS THAT
THERE'S LIKELY TRILLIONS OF EXOMOONS.
Narrator: ASTRONOMERS HAVE FOUND THOUSANDS OF PLANETS
ORBITING DISTANT STARS,
BUT NONE OF THEM APPEAR TO HAVE MOONS.
THERE HAVE TO BE EXOMOONS, OF COURSE THERE ARE EXOMOONS.
Narrator: ARE THEY SIMPLY TOO HARD TO FIND,
OR IS OUR OWN SOLAR SYSTEM, WHICH HAS MANY MOONS, UNIQUE?
NOW A NEW GENERATION OF ADVANCED TELESCOPES HUNTS FOR CLUES.
MAYBE WE'RE GONNA FIND SOMETHING REALLY, REALLY STRANGE.
LITERALLY THE FIRST EXOMOON WE FIND COULD BE EARTHLIKE.
Narrator: WHO WILL MAKE THE FIRST CONFIRMED DISCOVERY
AND SOLVE THE MYSTERY OF THESE MISSING MOONS?
-- Captions by VITAC -- www.vitac.com
CAPTIONS PAID FOR BY DISCOVERY COMMUNICATIONS
EARTH'S MOON DOMINATES THE NIGHT SKY.
ITS IMMENSE GRAVITY RAISES TIDES IN THE OCEANS,
AND ITS 27-DAY PASSAGE AROUND EARTH
MARKS THE MONTHS OF THE YEAR.
BUT OUR PLANET ISN'T ALONE IN HAVING A MOON.
A MOON IS DEFINED IN A NUMBER OF WAYS --
ONE, IT HAS TO BE SMALLER THAN ITS HOST PLANET,
AND IT HAS TO CIRCLE ITS HOST PLANET.
IF SOMETHING DOES THOSE TWO THINGS, IT'S A MOON.
Narrator: THERE ARE MORE THAN 150 MOONS IN OUR SOLAR SYSTEM,
EACH MOON IS DIFFERENT.
FROM VIOLENTLY VOLCANIC IO IN CLOSE ORBIT AROUND JUPITER,
TO SATURN'S LARGEST MOON, TITAN,
THAT CONCEALS VAST LAKES OF LIQUID METHANE AND ETHANE.
SCIENTISTS EXPECT ALIEN PLANETS IN DISTANT SOLAR SYSTEMS
TO HAVE MOONS, TOO.
THEY CALL THESE "EXOMOONS."
THE PROBLEM IS, NO MATTER HOW HARD ASTRONOMERS LOOK,
THEY CAN'T FIND THEM.
♪
THERE COULD BE UP TO A TRILLION EXOMOONS IN OUR GALAXY ALONE,
AND WE HAVE YET TO DISCOVER ONE.
Narrator: SCIENTISTS ARE DESPERATE TO MAKE THE FIRST CONFIRMED DISCOVERY
OF AN EXOMOON, NOT JUST TO PROVE THEY EXIST,
BUT BECAUSE MANY MOONS COULD BE HOST
TO SOMETHING VERY SPECIAL INDEED -- ALIEN LIFE.
♪
SCIENTISTS NOW BELIEVE THAT THE SURFACES
AND DEEP INTERIORS OF SOME MOONS
COULD BE A BETTER PLACE TO FIND LIQUID WATER
THAN THE PLANETS THEY SURROUND.
THESE MOONS COULD PROVIDE THE PERFECT CONDITIONS
FOR SOME FORM OF LIFE TO HAVE TAKEN HOLD,
JUST LIKE IT DID ON THE EARLY EARTH.
IN OUR SOLAR SYSTEM, SOME OF THE MOST LIKELY ENVIRONMENTS
FOR LIFE ARE NOT ON THE PLANETS, BUT THEY'RE ON THE MOONS.
IN OTHER STAR SYSTEMS, WHY SHOULD IT BE ANY DIFFERENT?
LIFE ON MOONS MAY BE FAR MORE COMMON THAN LIFE ON PLANETS.
Narrator: BUT MOONS ARE SMALLER THAN PLANETS.
THIS MAKES THEM HARDER TO DETECT.
SO SCIENTISTS ARE TURNING TO EVERMORE NOVEL
AND INGENIOUS METHODS TO TRACK THEM DOWN.
IN THE NETHERLANDS, ASTRONOMER MATT KENWORTHY
HAS RECENTLY MADE AN INCREDIBLE BREAKTHROUGH.
HE THINKS HE MAY HAVE UNCOVERED INDIRECT EVIDENCE
OF AN EXOMOON 430 LIGHT-YEARS FROM EARTH.
I THINK IT'S VERY EXCITING,
BECAUSE IT'S SOMETHING WHICH IS BRAND-NEW,
AND WE DON'T KNOW THE ANSWERS YET.
MATT'S DISCOVERY IS BASED ON AN EXTRAORDINARY OBSERVATION.
TO HUNT DOWN PLANETS, ASTRONOMERS LOOK FOR TINY DIPS
IN LIGHT AS THE PLANET PASSES IN FRONT OF ITS HOST STAR.
MATT FINDS ONE OF THESE DIPS,
BUT IT'S UNLIKE ANYTHING HE'S SEEN BEFORE --
SOMETHING ENORMOUS IS BLOCKING LIGHT FROM THE STAR.
WE TYPICALLY LOOK AT A SIGNAL FOR ABOUT SIX HOURS OR SO
WHILST THE PLANET BLOCKS OUT
A SMALL AMOUNT OF LIGHT FROM THE STAR.
THIS LASTED MUCH LONGER.
INSTEAD OF SIX HOURS, THIS LASTED OVER TWO MONTHS.
Narrator: AND EVEN STRANGER, IN PLACES THE VAST OBJECT
APPEARS TO LET LIGHT THROUGH.
INSTEAD OF A NICE, SMOOTH CURVE,
YOU CAN SEE LOTS OF RAPID VARIATION.
IT'S LIKE SOMEBODY'S
SWITCHING THE STAR ON AND OFF VERY RAPIDLY.
AND EVEN DURING INDIVIDUAL NIGHTS,
YOU CAN SEE THE STAR CHANGE BRIGHTNESS BY AS MUCH AS 50%.
Narrator: MATT IS CONVINCED THAT THIS WEIRD SIGNAL MEANS ONE THING --
THE OBJECT BLOCKING THE STARLIGHT
MUST BE AN ALIEN PLANET WITH MULTIPLE RINGS LIKE SATURN
BUT ON A MUCH LARGER SCALE.
GAPS IN THESE RINGS WOULD EXPLAIN
WHY IT'S LETTING LIGHT THROUGH.
AND IT ALSO HINTS AT AN EXTRAORDINARY POSSIBILITY.
COULD THERE BE EXOMOONS HIDING IN THE GAPS?
LET'S SEE IF WE CAN FIND SATURN.
AH, OKAY, THERE WE GO.
I CAN SEE THE RINGS.
♪
Narrator: SATURN'S RINGS ARE MADE FROM TRILLIONS OF ICY PARTICLES.
BUT THE GAPS FORM WHEN THESE PARTICLES COLLIDE
AND STICK TOGETHER TO CREATE TINY MOONLETS.
AS THEY SWEEP UP MORE AND MORE DEBRIS,
BOTH THE MOONLETS AND THE GAPS GROW BIGGER.
SCIENTISTS THINK THAT THIS IS HOW MOST MOONS FORM
AROUND NEWLY BORN PLANETS.
YOUNG PLANETS WITH RINGS
COULD BE NOTHING MORE THAN GIGANTIC MOON FACTORIES.
THE THING WE KNOW FROM OUR EXAMPLE OF THE SOLAR SYSTEM
IS THAT RINGS AND MOONS ARE RELATED.
IF YOU CAN FIND RINGS AROUND A PLANET,
THERE'S A VERY, VERY GOOD CHANCE THERE MUST BE MOONS.
SO LOOK FOR THE RINGS, AND LOOK FOR GAPS IN THE RINGS.
Narrator: MATT ANALYZES THE FLICKERING STARLIGHT
TO WORK OUT WHAT THE RINGS OF THE ALIEN PLANET
MIGHT LOOK LIKE.
WHAT HE FINDS IS TRULY INCREDIBLE.
AT LEAST 37 SEPARATE RINGS, 200 TIMES LARGER THAN SATURN'S,
SPAN OVER 110 MILLION MILES.
ONE OF THE GAPS BETWEEN THE RINGS
IS ALMOST 2.5 MILLION MILES WIDE.
MATT SUSPECTS IT COULD BE HOME
TO SOMETHING NEVER SEEN BEFORE...
...A GIANT EXOMOON IN THE FINAL STAGES OF FORMATION.
BUT TO CLEAR OUT A GAP THAT BIG, JUST HOW LARGE IS IT?
MATT USES COMPUTER SIMULATIONS TO FIND OUT.
Kenworthy: BECAUSE WE SEE THIS CLEARED GAP IN THE RING SYSTEM,
ONE POSSIBLE INTERPRETATION
IS THAT THERE IS A MOON FORMING RIGHT NOW,
AND IT'S VACUUMING UP -- IT'S USING GRAVITY TO CLEAR OUT
ALL THE DUST OF THAT PARTICULAR LOCATION IN THE RING SYSTEM.
AND HOW WIDE THAT RING GAP IS GIVES US A VERY GOOD ESTIMATE
OF HOW MASSIVE THE MOON IS RIGHT AT THIS MOMENT.
AND WE WORKED OUT THAT IT SHOULD BE SOMETHING
ON THE ORDER OF THE SIZE OF MARS.
Narrator: THE BIGGEST MOONS IN OUR SOLAR SYSTEM
ARE JUPITER'S GANYMEDE AND SATURN'S TITAN,
BUT MATT'S EXOMOON IS AT LEAST FOUR TIMES AS MASSIVE.
ON THE SCALE OF A ROCKY PLANET.
HIS DISCOVERY IS EXCITING,
BUT IT RESTS ON JUST ONE SINGLE OBSERVATION.
MATT NEEDS MORE DATA TO SAY FOR SURE THAT HIS GIANT,
MARS-SIZED EXOMOON IS REAL.
THE PROBLEM IS, HE HAS NO IDEA WHEN THE ALIEN-RINGED PLANET
WITH ITS EXOMOON WILL PASS IN FRONT OF ITS STAR AGAIN.
IT'S A VERY LARGE STRUCTURE, AND SO IT MUST TAKE
A VERY LONG TIME TO ORBIT.
SO IT WOULDN'T BE TOO SURPRISING
IF IT TOOK ANYWHERE BETWEEN 10 TO 20 YEARS
FOR THIS THING TO BLOCK THE STARLIGHT AGAIN.
WE'VE DETECTED A GIANT RING SYSTEM,
SOMETHING HUNDREDS OF TIMES THE SIZE OF SATURN'S RINGS.
HAVE WE INDIRECTLY DETECTED THE FIRST EXOMOONS?
POSSIBLY.
Narrator: WHILE MATT WAITS FOR NEW DATA TO WIN THE EXOMOON RACE,
OTHERS ARE HOT ON HIS HEELS AND HOPE TO BEAT HIM TO IT.
IN NEW MEXICO, ONE SCIENTIST PLANS TO FIND THESE MOONS
BY LISTENING TO THE NIGHT SKY.
Narrator: SCIENTISTS ARE IN A RACE
TO MAKE THE FIRST CONFIRMED DISCOVERY OF AN EXOMOON,
A MOON OUTSIDE OUR SOLAR SYSTEM THAT ORBITS AN ALIEN PLANET.
ASTRONOMER MARIALIS ROSARIO-FRANCO
PIONEERS A REMARKABLE NEW TECHNIQUE
TO DETECT THESE MOONS.
USING A RADIO TELESCOPE LIKE THIS ONE IN NEW MEXICO,
SHE ATTEMPTS TO TUNE IN TO THEIR GALACTIC BROADCASTS.
RADIO TELESCOPES DETECT RADIO WAVES,
A FORM OF LIGHT THAT WE CAN'T SEE
BUT IS THE BASIS FOR RADIO COMMUNICATION.
Rosario-Franco: WE ARE AT THE LONG WAVELENGTH ARRAY
AND WHAT WE HAVE IS ABOUT 200 ANTENNAS,
AND TOGETHER THEY MAKE UP A RADIO TELESCOPE.
Narrator: MARIALIS BELIEVES THAT THE GEOLOGY OF CERTAIN EXOMOONS
MAY TURN THEM INTO NATURAL RADIO TRANSMITTERS.
DISCOVERING THESE COULD BE AS SIMPLE
AS PICKING UP THEIR SIGNAL.
TO PROVE IT, SHE TUNES IN TO A MOON MUCH CLOSER TO HOME.
[ STATIC ]
Rosario-Franco: SO, WHAT WE'RE LISTENING TO RIGHT NOW,
YOU'LL NOTICE THEY SOUND LIKE POPPING SOUNDS.
Narrator: THIS IS THE RADIO SIGNAL FROM JUPITER'S MOON, IO.
THE TWO RADIO SIGNALS THAT IO MAKES ARE L- AND S-BURSTS.
"L" STANDS FOR "LONG-BURST," "S" STANDS FOR "SHORT."
WHAT WE'RE LISTENING TO RIGHT NOW ARE S-BURSTS.
Narrator: WHAT TURNS A MOON LIKE IO INTO A RADIO TRANSMITTER?
THE SURPRISING ANSWER?
VOLCANOES.
IO IS THE MOST VOLCANICALLY ACTIVE WORLD
IN THE SOLAR SYSTEM.
ITS HUNDREDS OF VOLCANOES SPEW OUT VAST AMOUNTS OF GAS.
JUPITER'S POWERFUL MAGNETIC FIELD CHARGES AND CORRALS
THIS GAS INTO AN ENORMOUS DOUGHNUT OF ELECTRIC FOG
THAT SURROUNDS THE PLANET.
AS IO ORBITS AROUND JUPITER,
IT INTERACTS WITH THIS FOG AND JUPITER'S MAGNETIC FIELD...
...TRIGGERING THE RELEASE OF RADIO WAVES FAR OUT INTO SPACE.
JUPITER HAS A STRONG MAGNETIC FIELD,
AND THAT INTERACTS WITH ONE OF ITS MOONS, IO,
AND THAT PRODUCES A TREMENDOUS AMOUNT OF RADIO ENERGY.
IF OTHER PLANETS HAVE MAGNETIC FIELDS
AND THEY HAVE MOONS LIKE IO,
WE MIGHT BE ABLE TO DETECT THAT RADIO ENERGY FROM THEM
WITHOUT EVER ACTUALLY HAVING SEEN THE PLANET
OR THE MOON THEMSELVES.
PLANETS LIKE JUPITER ARE INCREDIBLY COMMON IN OUR GALAXY,
THERE'S HUNDREDS OF BILLIONS OF THEM.
SO THIS MEANS THAT THERE MUST BE TRILLIONS OF EXOMOONS.
Narrator: SCIENTISTS HAVE DISCOVERED
OVER 1,000 GAS-GIANT PLANETS IN OUR GALAXY,
AND THEY EXPECT THEM TO HAVE STRONG MAGNETIC FIELDS.
IF VOLCANIC MOONS, LIKE IO, ORBIT THESE PLANETS,
THEN RADIO TELESCOPES MAY BE ABLE TO DETECT THEM.
NOT ONLY THAT, ANY LUNAR RADIO SIGNAL THAT WE PICK UP
WILL GIVE US CRITICAL INFORMATION ABOUT THE MOON.
WHEN WE ANALYZED THE INTENSITY
AND THE FREQUENCY OF THESE SIGNALS,
WE CAN EXTRAPOLATE PHYSICAL PROPERTIES
OF BOTH THE MOON AND THE PLANET AND HOW THEY'RE INTERACTING.
NOT ONLY THAT, WE CAN EXTRAPOLATE THE RADIOS OF BOTH
AND ALSO HOW DISTANT THE MOON IS FROM ITS HOST PLANET.
Narrator: IF MARIALIS IS RIGHT, SHE'LL BE ABLE TO FIND VOLCANIC EXOMOONS
AND MEASURE THEIR SIZE JUST BY LISTENING TO THE NIGHT SKY.
IT'S AN AMAZING CONCEPT.
BUT MARIALIS HAS BEEN DOING THIS FOR OVER A YEAR NOW,
AND SHE'S YET TO FIND A SIGNAL.
IT COULD BE THAT THE RADIO SIGNALS
ARE TOO DISTANT AND WEAK.
BUT SOON, A NEW GENERATION OF RADIO TELESCOPES
WILL OFFER EVEN GREATER SENSITIVITY.
MARIALIS BELIEVES DETECTING A VOLCANIC EXOMOON
IS ONLY A MATTER OF TIME.
Tremblay: THESE VOLCANIC MOONS, LIKE IO, COULD BE,
LIKE, BEACONS IN THE VOID -- THESE RADIO BEACONS
THAT WE CAN FINALLY USE TO DISCOVER AN EXOMOON.
SO FAR, OUR TELESCOPES AREN'T NEARLY SENSITIVE ENOUGH
TO ACTUALLY DETECT VOLCANIC EMISSION IN AN EXOMOON.
BUT THERE ARE FUTURE TELESCOPES ON THE HORIZON
THAT MAY START TO ACHIEVE THE SENSITIVITY NEEDS
REQUIRED TO ACTUALLY MAKE SUCH A STUNNING OBSERVATION.
Narrator: WHILE MARIALIS HUNTS FOR RADIO SIGNALS FROM VOLCANIC MOONS,
OTHER ASTRONOMERS HAVE SET THEIR SIGHTS
ON SOMETHING EVEN MORE EXTRAORDINARY.
THEY'RE SEARCHING FOR SOMETHING
STRAIGHT OUT OF SCIENCE FICTION --
HABITABLE, EARTHLIKE MOONS THAT COULD HARBOR ALIEN LIFE.
AND WILL THIS OCEAN EXPLORER BE THE FIRST TO PROVE
THE EXISTENCE OF LIFE ON A MOON WITHIN OUR OWN SOLAR SYSTEM?
Narrator: THE RACE IS ON TO SOLVE THE MYSTERY
OF THE MISSING EXOMOONS --
MINI WORLDS THAT ORBIT AROUND ALIEN PLANETS.
SO FAR, SCIENTISTS HAVE TANTALIZING EVIDENCE
OF AN EXOMOON THE SIZE OF MARS
FORMING WITHIN THE RINGS OF A NEWLY BORN PLANET.
BUT TO TRULY FULFILL THE DREAMS OF SCIENCE FICTION,
ASTRONOMERS WANT TO FIND AN EARTHLIKE MOON
THAT CAN SUSTAIN LIFE, LIKE US.
Oluseyi: WHAT DO WE MEAN WHEN WE SAY
WE'RE LOOKING FOR AN EARTHLIKE PLACE?
WELL, WE'RE TALKING ABOUT HAVING SURFACE LIQUIDS,
WE'RE TALKING ABOUT HAVING AN ATMOSPHERE,
WHICH IS NECESSARY FOR SURFACE LIQUIDS,
AND HAVING SUFFICIENT ENERGY TO SUPPORT LIFE.
IF WE WERE TO FIND LIFE ON AN EARTHLIKE MOON,
THAT WOULD CHANGE EVERYTHING.
Narrator: DAVID KIPPING IS AN ASTRONOMER
WHO HUNTS FOR EARTHLIKE EXOMOONS THAT COULD HARBOR LIFE.
Kipping: FOR ME, ONE OF THE MAIN REASONS TO LOOK FOR EXOMOONS
HAS ALWAYS BEEN THAT THEY MAY OUTNUMBER HABITABLE PLANETS
OUT THERE IN THE UNIVERSE.
Narrator: DAVID HAS DISCOVERED SOMETHING INTRIGUING --
A GAS GIANT 4,000 LIGHT-YEARS FROM EARTH
ABOUT THE SIZE OF JUPITER, CALLED KEPLER-1625B.
IT ORBITS ITS STAR AT ABOUT THE SAME DISTANCE
AS THE EARTH GOES AROUND THE SUN.
IT'S COMPLETELY UNINHABITABLE FOR LIFE AS WE KNOW IT.
IT HAS A THICK, SWIRLING ATMOSPHERE OF NOXIOUS GAS
AND A TINY, ROCKY CORE.
DAVID THINKS THIS PLANET MAY HAVE AN EXOMOON.
WE LOOK FOR EXOMOONS IN A VERY SIMILAR WAY
TO WHERE WE LOOK FOR EXOPLANETS.
WE HAVE A STAR WHICH IS EMITTING PLENTY OF LIGHT,
AND THERE IS A PLANET NEARBY.
AND AS IT PASSES IN FRONT OF THE STAR,
IT WILL NOW BE BLOCKING OUT STARLIGHT.
SO IF I MEASURE THE BRIGHTNESS OF THE STAR OVER TIME,
IT WOULD SEEM TO DECREASE FOR A SHORT INTERVAL.
THAT TELLS ME THERE'S A PLANET THERE.
NOW, IF THIS PLANET ALSO HAS A MOON JUST AHEAD HERE,
YOU CAN SEE THE PLANET-MOON SYSTEM,
AS IT MOVES ACROSS, THE MOON IS GOING TO ENTER TRANSIT FIRST.
SO I'M GOING TO SEE ANOTHER EXTRA LITTLE DIP OVER HERE.
AND THEN, LATER ON, THE MOON IS GOING TO EXIT TRANSIT FIRST.
I'M GOING TO ACTUALLY SEE A LITTLE EGRESS FEATURE.
SO WE LOOK FOR THESE TELL-TALE SIGNATURES OF MOONS IN OUR DATA,
AND IF WE SEE SOMETHING LIKE THIS,
WE KNOW THAT WE HAVE A GOOD EXOMOON CANDIDATE.
Narrator: IT TAKES DAVID SEVEN YEARS TO FINALLY FIND A PLANET
WITH THE ELUSIVE SIGNATURE OF A POTENTIAL EXOMOON.
THIS IS ONE OF THE THREE TRANSITS OF KEPLER-1625B
AS OBSERVED BY THE KEPLER TELESCOPE.
WHAT WE'RE LOOKING AT HERE IS A BIG DIP IN LIGHT
DUE TO THE PLANET PASSING IN FRONT OF THE STAR.
THAT TELLS US THAT THE SIZE OF THE PLANET IS LARGE.
YOU'LL ALSO NOTICE THAT THERE'S SOME SMALL SIGNATURES,
SOME LITTLE SHOULDERS HERE.
WE THINK THE MOON IS ACTUALLY SLIGHTLY AHEAD OF THE PLANET.
AND THEN EVENTUALLY THE MOON LEAVES THE STAR.
THAT'S WHAT'S HAPPENING ON THAT LITTLE SHOULDER THERE,
THE MOON HAS NOW LEFT THE DISK OF THE STAR.
THERE'S THESE FOUR KEY MOMENTS IN TIME --
THE MOON ENTERING, THE PLANET ENTERING,
THE MOON EXITING, AND THE PLANET EXITING.
Narrator: DAVID'S DISCOVERY IS REMARKABLE.
IF CONFIRMED, THIS IS THE FIRST DEFINITIVE PROOF
OF A MOON OUTSIDE OUR SOLAR SYSTEM.
BUT IS IT THE ELUSIVE EARTHLIKE MOON
THAT DAVID HAS BEEN SEARCHING FOR?
OBSERVATIONS SUGGEST THAT THE EXOMOON, IF IT EXISTS,
IS MASSIVE, AT LEAST THREE TIMES THE SIZE OF EARTH.
THAT MEANS IT'S LIKELY TO HAVE AN ATMOSPHERE
AND PERHAPS EVEN A VAST OCEAN OF LIQUID WATER.
BILLIONS OF YEARS AGO,
THIS COULD HAVE BEEN THE PERFECT ENVIRONMENT
FOR LIFE TO TAKE HOLD AND FLOURISH.
BUT SADLY, TODAY, IT'S MOST LIKELY STERILE.
ITS AGING STAR HAS GROWN HOTTER
AND IS SLOWLY COOKING THE MOON'S OCEAN.
THIS MOON ALMOST CERTAINLY IS NOT A PLACE
WHERE WE WOULD EXPECT LIFE TO BE LIVING THERE RIGHT NOW.
IT'S ALMOST THE BOILING POINT OF WATER, HOWEVER, IN THE PAST,
I THINK IT WOULD HAVE HAD GOOD CHANCES
THAT ITS TEMPERATURE WOULD HAVE BEEN THE RIGHT LEVEL FOR LIFE,
MAYBE, TO HAVE THRIVED.
THEREFORE DISCOVERING MOONS LIKE THIS MOON
GIVES US A LOT OF CONFIDENCE THAT MAYBE THERE ARE
PLENTY OF HABITABLE MOONS OUT THERE IN THE UNIVERSE.
Narrator: DAVID'S DISCOVERY IS A POTENTIAL GAME CHANGER.
THE VERY FIRST EXOMOON THAT WE CONFIRM AS REAL
COULD TURN OUT TO BE THE BOILING CORPSE OF A ONCE LIVING WORLD.
BUT CAN OTHER ASTRONOMERS GO ONE BETTER
AND FIND A HABITABLE EXOMOON THAT'S STILL ALIVE TODAY?
AT MOUNT GRAHAM IN ARIZONA,
ASTRONOMER JUSTIN CREPP IS ON THE HUNT FOR PLANETS
THAT COULD HIDE EARTHLIKE MOONS.
HE THINKS THERE COULD BE COUNTLESS MOONS
THAT ARE HABITABLE RIGHT NOW.
WE JUST NEED TO FIND THEM.
Crepp: SCIENCE FICTION IS ALWAYS
10 OR 20 YEARS AHEAD OF REGULAR SCIENCE,
BUT WHAT'S REALLY INTERESTING NOW
IS WE'RE ACTUALLY HAVING THE TECHNOLOGIES
AND THE CAPABILITIES TO REALISTICALLY DETECT
THE SIGNALS OF EARTHLIKE MOONS FOR THE VERY FIRST TIME.
Narrator: FINDING EARTHLIKE EXOMOONS
PUSHES THE CAPABILITY OF OUR TECHNOLOGY TO ITS LIMIT.
JUSTIN USES ONE OF THE LARGEST TELESCOPES
IN THE NORTHERN HEMISPHERE...
...THE LARGE BINOCULAR TELESCOPE,
THE BIGGEST PAIR OF BINOCULARS ON THE PLANET.
Crepp: IT'S FLOATED ON A VERY THIN FILM OF OIL
THAT IS ESSENTIALLY FRICTIONLESS
AND ALLOWS IT TO MOVE WITH SUCH PRECISE AND EXQUISITE MOTION.
THIS TELESCOPE IS UNIQUE IN THE SENSE
THAT IT HAS A VERY LARGE SET OF MIRRORS,
BUT NOT JUST THAT, IT HAS THE ABILITY
TO CORRECT FOR EARTH'S TURBULENT ATMOSPHERE.
AND SO IT ALLOWS US TO CREATE VERY CRISP IMAGES
AS IF WE WERE IN SPACE.
Narrator: IS JUSTIN SET TO DISCOVER THE FIRST HABITABLE EARTHLIKE MOON?
AND HAVE SCIENTISTS IN AUSTRIA PROVED
THAT THERE COULD BE ALIEN LIFE ON A MOON
A WHOLE LOT CLOSER TO HOME?
Narrator: SCIENTISTS ARE ON THE HUNT FOR HABITABLE EXOMOONS --
EARTHLIKE MOONS THAT COULD HARBOR ALIEN LIFE.
TANTALIZING EVIDENCE OF AN EXOMOON
WITH A POTENTIAL GIANT OCEAN PROVES A NEAR MISS.
NOW ONE OF THE LARGEST TELESCOPES ON THE PLANET
JOINS THE RACE.
ASTRONOMER JUSTIN CREPP USES THIS MIGHTY MACHINE
TO HUNT FOR PLANETS THAT COULD HAVE HABITABLE EARTHLIKE MOONS
IN ORBIT AROUND THEM.
HE LOOKS FOR MOON-RICH GAS GIANTS
THAT LIE WITHIN THE SO-CALLED HABITABLE ZONE OF THEIR STAR --
THE DISTANCE WHERE IT'S NOT TOO HOT AND NOT TOO COLD
BUT JUST RIGHT FOR LIFE AS WE KNOW IT.
Plait: IN OUR SOLAR SYSTEM, JUPITER ORBITS PRETTY FAR FROM THE SUN,
AND ITS ICY MOONS ARE ICY, THE WATER IS FROZEN.
BUT IF JUPITER TO HAPPENED TO ORBIT WHERE THE EARTH IS,
THOSE ICY MOONS WOULD BE LIQUID,
THEY'D HAVE LIQUID WATER ON THEIR SURFACES
AND MAYBE ATMOSPHERES.
WHEN WE LOOK AT THESE OTHER STARS,
WE SEE THESE GIANT PLANETS
ORBITING RIGHT AROUND THE PLACE WHERE THEY'D BE GETTING
AS MUCH LIGHT AND HEAT AS THE EARTH DOES.
IF THEY HAVE THESE KINDS OF MOONS,
THAT MIGHT BE A REALLY COOL PLACE TO LOOK FOR LIFE.
Narrator: TODAY, JUSTIN STUDIES A JUPITER-SIZED PLANET
CALLED KEPLER-86B.
HE ANALYZES THE ORBIT TO FIND OUT
HOW FAR IT SITS FROM ITS STAR.
DOES THIS PLANET ORBIT WITHIN THE HABITABLE ZONE OF ITS STAR?
THE LENGTH OF THE YEAR OF KEPLER 86
IS VERY SIMILAR TO THE AMOUNT OF TIME
THAT IT TAKES EARTH TO GO AROUND THE SUN, AROUND 280 DAYS,
WHICH INDICATES FOR THIS TYPE OF STAR
THAT IT IS INDEED IN THE HABITABLE ZONE.
Narrator: IF THIS GAS GIANT PLANET HOSTS A HABITABLE MOON,
WE CAN IMAGINE ITS COSMIC EVOLUTION.
JUST A FEW MILLION YEARS OLD,
THE NEWBORN MOON RESEMBLES A SCORCHED BALL OF ROCK.
FEROCIOUS VOLCANIC ERUPTIONS BLANKET THE MOON
IN A THICK FOG OF GAS.
THE MOON'S GRAVITY HOLDS ONTO THIS FOG.
IT GIVES THE MOON AN ATMOSPHERE AND SHIELDS IT
AGAINST LETHAL RADIATION FROM ITS NEIGHBORING PLANET.
WATER CONDENSES ON THE MOON'S SURFACE,
FORMING RIVERS, LAKES, AND OCEANS...
...PERHAPS ALLOWING LIFE TO TAKE HOLD, EVOLVE, AND THRIVE.
BUT DOES THIS HABITABLE EARTHLIKE MOON REALLY EXIST?
JUSTIN SEARCHES FOR SIGNS OF A MOON IN THE DATA.
THIS FIGURE SHOWS THE TRANSIT SIGNAL,
AND WHAT WE SEE IS THAT THERE'S A LARGE DIP THAT OCCURS
WHEN THE PLANET PASSES IN FRONT OF THE STAR.
Narrator: FOR NOW, THE DATA LACKS THE TELL-TALE SIGNATURE OF A MOON.
BUT THE SEARCH IS NOT OVER.
♪
NASA HAS LAUNCHED A NEW SPACE TELESCOPE CALLED "TESS."
JUSTIN PLANS TO USE THIS IN COMBINATION
WITH THE LARGE BINOCULAR TELESCOPE
TO ACCELERATE THE HUNT FOR AN EARTHLIKE EXOMOON.
Crepp: NASA'S TESS MISSION IS VERY IMPORTANT
IN REGARDS TO EXOMOONS.
TESS IS GOING TO PROVIDE THESE TARGETS FOR US,
AND WE'RE GOING TO USE FACILITIES ON THE GROUND,
LIKE THE LARGE BINOCULAR TELESCOPE,
TO CHARACTERIZE THE STAR SO THAT WE UNDERSTAND THE PLANET
SO THAT WE ULTIMATELY UNDERSTAND THE EXOMOON.
WE ARE REALLY CLOSE TO BEING ABLE TO DETECT EXOMOONS.
IT COULD HAPPEN TONIGHT.
IF WE DETECT AN EXOMOON AROUND A GAS GIANT PLANET, SAY,
AND THAT GAS GIANT IS RECEIVING THE SAME AMOUNT OF LIGHT
AND HEAT FROM ITS STAR AS WE DO,
LITERALLY THE FIRST EXOMOON WE FIND COULD BE EARTHLIKE.
AND THAT, TO ME, IS EXTREMELY EXCITING.
Narrator: ASTRONOMERS ARE ON THE THRESHOLD
OF DISCOVERING THE FIRST EXOMOONS IN OUR GALAXY...
...MINI WORLDS THAT MAY EVEN HARBOR LIFE.
SO FAR, THEY'VE TARGETED EARTHLIKE MOONS
AROUND GAS GIANTS THAT ORBIT CLOSE TO THEIR STAR.
BUT SOME BELIEVE THAT MOONS OUTSIDE THE HABITABLE ZONE
MAY HARBOR LIFE, TOO, NOT ON THE SURFACE
BUT DEEP BELOW THEIR FROZEN CRUSTS.
A CLUE COMES FROM A MOON IN OUR OWN SOLAR SYSTEM,
745 MILLION MILES OUTSIDE OUR SUN'S HABITABLE ZONE,
WHERE THERE IS BARELY ANY WARMTH FROM SUNLIGHT.
SATURN'S MOON, ENCELADUS, HAS A SURFACE TEMPERATURE
OF ALMOST 330 DEGREES BELOW FREEZING.
WHEN THE CASSINI ROBOT SPACECRAFT
PASSES OVER ITS SOUTH POLE,
IT DISCOVERS SOMETHING SEEMINGLY IMPOSSIBLE...
...JETS OF WATER SHOOTING OUT THROUGH CRACKS
IN THE MOON'S ICY CRUST AT MORE THAN 800 MILES PER HOUR.
THE IMAGES REVEAL SOMETHING EXTRAORDINARY
ABOUT THE INTERIOR OF THIS MOON.
AS ENCELADUS ORBITS AROUND SATURN,
THE EVER-CHANGING PULL FROM THE MASSIVE PLANET
WARPS AND CRACKS ITS ICY SURFACE.
HUGE CREVASSES OPEN UP,
EXPOSING A WARM, LIQUID OCEAN BENEATH THE ICY CRUST.
SATURN'S GRAVITY FLEXES AND HEATS UP THE MOON'S ROCKY CORE,
GIVING RISE TO POWERFUL HYDROTHERMAL VENTS.
THESE VENTS EJECT BOILING MINERAL-RICH WATER
INTO THE OCEAN,
CREATING ONE OF THE SOLAR SYSTEM'S GREATEST MIRACLES --
LIQUID WATER WARM ENOUGH TO SUPPORT LIFE.
Plait: WHEN YOU LOOK AT ENCELADUS, IT HAS ALL THE INGREDIENTS
FOR LIFE AS WE KNOW IT --
IT'S GOT A LIQUID-WATER OCEAN INSIDE OF IT,
IT'S GOT AN ENERGY SOURCE, WHICH YOU NEED FOR LIFE,
AND THAT COMES FROM SATURN STRETCHING
AND COMPRESSING THE MOON ITSELF.
IT'S NOT THAT SILLY TO THINK THAT THERE COULD BE
THESE SIMILAR CONDITIONS AROUND OTHER STARS.
Narrator: AND ENCELADUS IS NOT ALONE.
JUPITER'S ICE MOON, EUROPA,
MAY HAVE THE LARGEST OCEAN IN THE SOLAR SYSTEM.
THE SAME GRAVITATIONAL HEATING EFFECT
KEEPS THIS OCEAN PERMANENTLY WARM,
AND ITS THICK ICE CRUST
COULD SHIELD AGAINST THE DEADLY RADIATION
FROM JUPITER'S POWERFUL MAGNETIC FIELD.
PEOPLE TALK ABOUT A HABITABLE ZONE,
A PLACE WHERE A PLANET HAS TO BE
TO BE WARM ENOUGH FOR LIQUID WATER,
BUT IN FACT THE REAL ACTION, WHERE WATER IS CONCERNED,
IS IN THE OUTER SOLAR SYSTEM.
SO WHEN YOU THINK ABOUT THE RIGHT CONDITIONS FOR LIFE,
YOU WANT TO LOOK FARTHER AWAY FROM THE STAR
THAN MIGHT FIRST HAVE ASSUMED.
Narrator: SCIENTISTS THINK THAT ACROSS THE GALAXY
THERE COULD BE BILLIONS OF ICY EXOMOONS
JUST LIKE ENCELADUS THAT HARBOR HIDDEN OCEANS.
THE BIG QUESTION -- COULD LIFE EXIST INSIDE AN ICY EXOMOON?
Narrator: SCIENTISTS SEARCHING FOR ALIEN LIFE
ARE TURNING THEIR ATTENTION TO ICE MOONS WITH HIDDEN OCEANS.
COULD SOME OF THESE MOONS HARBOR LIFE
BENEATH THEIR FROZEN CRUSTS?
CHEMIST CHRISTIAN PAULIK WANTS TO FIND OUT.
HE STUDIES TINY, MICROSCOPIC LIFE-FORMS CALLED "ARCHAEA."
ARCHAEA FEED OFF THE NUTRIENT-RICH WATERS
AROUND HYDROTHERMAL VENTS
AT THE BOTTOM OF EARTH'S DEEPEST OCEANS.
CHRISTIAN WANTS TO TEST IF THESE MICROORGANISMS
COULD SURVIVE THE EXTREME ENVIRONMENT
AT THE BOTTOM OF AN ICE MOON'S OCEAN.
OKAY, HERE WE HAVE OUR LITTLE MICROORGANISMS.
AND WE HOPE WE CAN SHOW
THAT MICROORGANISMS LIKE THIS ONE HERE
CAN ALSO SURVIVE ON CONDITIONS LIKE ON ENCELADUS.
Narrator: SCIENTISTS THINK THE PRESSURE
AT THE BOTTOM OF ENCELADUS' OCEAN
IS EQUIVALENT TO 100 TIMES THE ATMOSPHERIC PRESSURE ON EARTH.
THE WATER IS UP TO 190 DEGREES FAHRENHEIT,
AND IT'S LACED WITH TOXIC CHEMICALS.
IF YOU CAN SHOW THAT THE MICROORGANISMS WE FIND HERE
ON EARTH CAN LIVE UNDER THAT CONDITION,
THERE MIGHT BE THE POSSIBILITY
THAT WE ALSO FIND THIS KIND OF ORGANISMS ON AN ICY MOON.
Narrator: CHRISTIAN'S COLLEAGUE, PATRICIA,
TRANSFERS THE MICROORGANISMS INTO A PIECE OF PIPING
AND CONNECTS IT TO A PRESSURE CHAMBER.
Paulik: NOW WE CONNECT IT TO THE REACTOR.
Narrator: SHE INCREASES THE PRESSURE.
CAN THE MICROORGANISMS SURVIVE?
PATRICIA LOOKS FOR EVIDENCE OF ACCUMULATION OF METHANE GAS,
A SURE SIGN THAT THE MICROBES ARE FUNCTIONING NORMALLY.
WHAT WE CLEARLY SEE HERE IS THAT OUR MICROORGANISMS GROW
AND THAT THEY PRODUCED METHANE.
THAT'S QUITE FINE. [ CHUCKLES ]
THE RESULTS ARE POSITIVE.
THE MICROORGANISMS ARE PRODUCING METHANE.
THEY ARE ALIVE AND WELL.
THE EXPERIMENT PROVES THAT ENCELADUS
AND ICY EXOMOONS LIKE IT ARE HABITABLE
AND POTENTIALLY NOT JUST FOR SIMPLE LIFE.
AROUND EARTH'S HYDROTHERMAL VENTS,
LARGER CREATURES SUCH AS TUBEWORMS, SHRIMP,
AND CRABS CAN FEED OFF MICROORGANISMS.
THIS ALLOWS A COMPLEX ECOSYSTEM TO THRIVE
WITH NO EXPOSURE TO SUNLIGHT.
IT'S POSSIBLE THAT SIMILAR CREATURES COULD LIVE
ON THE SEA FLOOR OF ICY EXOMOONS, AS WELL.
ALIEN MICROORGANISMS COULD BE THE BOTTOM
OF A COMPLEX FOOD CHAIN.
Oluseyi: THE SAME PHYSICS AND CHEMISTRY
THAT HAPPENS HERE IN OUR SOLAR SYSTEM
HAPPENS EVERYWHERE IN THE UNIVERSE.
SO JUST LIKE WE HAVE TIDAL HEATING ON ENCELADUS
THAT COULD SUPPORT LIFE AT THE BOTTOM OF ITS OCEAN,
THE SAME THING COULD BE GOING ON IN EXOMOONS
ALL AROUND THE GALAXY.
SO THE EXOMOONS COULD BE BREEDING GROUNDS
FOR LIFE THROUGHOUT THE UNIVERSE.
Narrator: SCIENTISTS SEARCHING FOR HABITABLE EXOMOONS
NOW HAVE TWO TARGETS --
EARTHLIKE MOONS AROUND GAS GIANTS
AND ICE MOONS WITH HIDDEN OCEANS.
THEY SUSPECT THESE COMPANION WORLDS
COULD BE MORE LIKELY TO HOST LIFE
THAN THE PLANETS THEY ORBIT, BUT THEY NEED PROOF.
FOR THAT, MOST SCIENTISTS ARE PINNING THEIR HOPES ON EUROPA,
AN ICE MOON CLOSER TO EARTH AND MUCH LARGER.
♪
Howett: ONE OF THE MOST EXCITING THINGS ABOUT EUROPA
IS IT HAS POTENTIAL FOR LIFE,
BUT IT'S A LOT CLOSER THAN ENCELADUS
AND SO IT MAKES IT AN EASIER PLACE TO EXPLORE
FROM THAT PERSPECTIVE.
Narrator: EUROPA IS ROUGHLY THE SIZE OF EARTH'S MOON,
BROWN STREAKS CRISSCROSS ITS ICY SURFACE.
IT'S THOUGHT THESE MARKINGS COULD BE SEA SALT
THAT SEEPS THROUGH CRACKS IN THE ICE.
JUPITER'S FEROCIOUS RADIATION BELT
THEN BAKES THIS SALT DARK BROWN.
NEW OBSERVATIONS BY THE HUBBLE SPACE TELESCOPE
SUGGEST THAT, LIKE SATURN'S SMALLER MOON, ENCELADUS,
PLUMES OF WATER MAY ERUPT FROM EUROPA'S SURFACE.
Thaller: EUROPA MAY HOLD SOME OF THE BEST CHANCES
OF FINDING LIFE OUTSIDE THE EARTH.
THERE IS A LIQUID-WATER OCEAN UNDERNEATH A LAYER OF ICE
THAT PROBABLY CONTAINS AS MUCH AS TWICE
OF ALL OF THE OCEANS' WATER ON THE EARTH.
WE KNOW ALSO THAT THERE'S INTERESTING CHEMISTRY THERE --
THERE'S SALT, THERE'S ORGANIC MOLECULES.
THE QUESTIONS IS CAN WE ACTUALLY GO THERE AND SAMPLE THIS WATER,
SEE IF ANYTHING IS LIVING INSIDE IT?
Narrator: TO FIND ALIEN LIFE ON EUROPA
MEANS DRILLING THOUGH TENS OF MILES OF ICE...
...AND SEARCHING AN OCEAN THAT COULD BE ALMOST 100 MILES DEEP.
BUT ONE SCIENTIST HAS ANOTHER PLAN.
WILL HIS ROBOT BE THE FIRST TO FIND ALIEN LIFE ON AN ICE MOON?
♪
Narrator: IN THE REMOTE ALASKAN ARCTIC,
NASA ENGINEER ANDY KLESH IS READY TO TEST A ROBOT
THAT HE HOPES COULD ONE DAY EXPLORE THE OCEAN
BENEATH THE ICY SURFACE OF EUROPA.
WE TRAVELED TO BARROW, ALASKA,
THE MOST NORTHERN POINT OF THE UNITES STATES.
AND THERE WE HAVE ACCESS TO PERMAFROST LAKES
WITH METHANE SEEPS THAT ARE BUBBLING UP FROM THE BOTTOM
AND ALSO THE ARCTIC OCEAN.
Narrator: HERE THE ICE-COVERED LAKES MIMIC FEATURES
OF EUROPA'S FRACTURED SURFACE.
ON EARTH, ALGAE AND MICROBES LIKE TO ANCHOR THEMSELVES
BENEATH THE ICE.
ANDY THINKS THAT ALIEN MICROBES ON EUROPA MAY DO THE SAME THING.
SO HE DESIGNS HIS ROBOT TO DRIVE UPSIDE DOWN
UNDERNEATH THE SURFACE ICE.
Klesh: RATHER THAN EXPLORE THE VAST REACHES OF OCEAN WATER,
WE FOUND THAT IF WE BUILT A ROVER
THAT COULD ACTUALLY SURVIVE AND THRIVE
ON THE UNDERSIDE OF THE ICE,
IT MIGHT BE ABLE TO BETTER FIND SIGNS OF LIFE
WITHOUT HAVING TO SEND DOWN TO THE FAR DEPTHS
AND THE HIGH PRESSURES THAT WE HAVE AT BOTTOM.
Narrator: ANDY'S TEAM IS WORKING ON A DEVICE TO ENABLE THE ROBOT
TO EXTRACT SAMPLES OF ICE AND WATER.
THE ROBOT COULD ANALYZE THESE
AND POTENTIALLY BRING THEM BACK TO EARTH.
Klesh: WE CAN MAINTAIN A VERY-LOW-POWER MODE,
BECAUSE OUR WHEELS ARE BASICALLY CIRCULAR SAW BLADES --
THEY DIG INTO THE ICE,
AND THEY ALLOW US TO STAY IN ONE PLACE UNDER THERE.
THIS ALLOWS US TO SIT, STARE,
AND OBSERVE FOR LONG PERIODS OF TIME,
COLLECTING AS MUCH INFORMATION AS WE CAN.
Narrator: THE TEAM ALSO TESTS THIS NEW PROTOTYPE
THAT'S DESIGNED TO FOLD UP AND FIT THROUGH A BOREHOLE.
IT'S EARLY DAYS FOR A MISSION TO EXPLORE EUROPA'S OCEAN,
THE CHALLENGES ARE IMMENSE
AND WILL TEST OUR TECHNOLOGY AND INGENUITY TO THE LIMIT.
BUT IT WILL BE WORTH IT, BECAUSE IF SCIENTISTS CAN FIND
EVEN SIMPLE ALIEN LIFE-FORMS ON A MOON,
IT WILL MEAN THAT OUR GALAXY COULD BE FILLED WITH LIFE.
♪
IF THERE WAS LIFE ON ANY OTHER PLACE IN OUR SOLAR SYSTEM,
BE IT ENCELADUS, BE IT EUROPA,
IT WOULD BE A TOTAL GAME CHANGER.
Plait: IF WE EVEN FIND A MICROBE ON EUROPA,
THAT MEANS LIFE CAN EXIST IN CONDITIONS
THAT ARE COMPLETELY DIFFERENT
THAN WHAT HAPPENED HERE ON EARTH 4 OR SO BILLION YEARS AGO.
IF THAT'S THE CASE,
THEN THAT MEANS WE MIGHT BE ABLE TO FIND LIFE
EVERYWHERE WE LOOK IN THE UNIVERSE.
Narrator: IF LIFE CAN GET STARTED ON ANOTHER WORLD
WITHIN OUR SOLAR SYSTEM,
THEN WE'LL KNOW FOR SURE IT CAN GET STARTED ANYWHERE
THE CONDITIONS ARE RIGHT ON BILLIONS OF HABITABLE PLANETS
THROUGHOUT THE MILKY WAY AND BILLIONS OF HABITABLE MOONS.
I THINK IF EUROPA WERE TO SHOW
THAT LIFE IS POSSIBLE ON THESE ICY WORLDS,
THEN THE PUSH TO EXPLORE OTHER ICY WORLDS IN OUR SOLAR SYSTEM
AND OUTSIDE OF OUR SOLAR SYSTEM WOULD BE HUGE.
Narrator: DISCOVERING ALIEN LIFE ON A MOON COULD BE THE CATALYST
THAT PUSHES US TO EXPLORE BEYOND OUR SOLAR SYSTEM.
Oluseyi: NOT ONLY ARE WE GOING TO LOOK FOR LIFE
EVERYWHERE IN OUR SOLAR SYSTEM.
WE'RE NOW GOING TO LOOK FOR LIFE
EVERYWHERE IN THE GALAXY AND THE UNIVERSE.
THE EXOMOONS, THE EXOPLANETS, WHO KNOWS?
IT CAN BE EVERYWHERE.
Narrator: IN THE LAST DECADE,
WE'VE WITNESSED A REVOLUTION IN ASTRONOMY
AS SCIENTISTS STARTED TO FIND PLANET AFTER PLANET
AROUND DISTANT STARS.
THE COMING DECADES COULD WITNESS A SIMILAR REVOLUTION,
AS HUNDREDS OF EXOMOONS ARE DISCOVERED, TOO,
ADDING A WHOLE NEW DIMENSION TO THE SEARCH FOR LIFE.
SOME EXOMOONS MAY EVEN BE HOME TO ADVANCED ALIENS
WHO MIGHT PONDER WHETHER LIFE COULD EVER FLOURISH ON A PLANET
AND NOT A MOON LIKE THEIRS.
Tremblay: IF YOU CAN IMAGINE US MAKING CONTACT
WITH AN ADVANCED LUNAR CIVILIZATION,
THEY MIGHT THINK WE'RE THE WEIRD ONES,
BEING LIFE ON A PLANET RATHER THAN ON A MOON.
Oluseyi: IF THERE WERE ALIEN INTELLIGENT BEINGS OUT THERE
AND THEY WERE TO SEE EARTH,
THEY PROBABLY WOULD LOOK AT US AND SAY,
"WHAT WEIRD KIND OF PLANET IS THAT?"
Narrator: WE MIGHT BE THE ODD ONES OUT.