Original subtitles

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.