[dramatic percussion music]
- HI, THERE, I'M KAJA DUNN.
WELCOME TO "NASA LAUNCHPAD."
ARE WE ALONE?
NO, NOT YOU OR ME
BUT EVERYONE, EVERYTHING WE KNOW,
EARTH!
ARE WE ALONE IN THE UNIVERSE?
OR IS EARTH NOT SO UNIQUE AFTER ALL?
COULD THERE BE OTHER EARTHLIKE BODIES
THROUGHOUT OUR UNIVERSE?
AND IF SO, COULD THEY HARBOR LIFE?
I KNOW SOME OF THESE QUESTIONS
MIGHT SEEM A BIT OUT OF THE ORDINARY,
BUT I'M NOT THE ONLY ONE ASKING THEM.
THERE ARE A LOT OF SCIENTISTS WONDERING THESE SAME THINGS,
AND THEY'RE EVEN SEARCHING FOR ANSWERS.
IT'S ONE OF THE NEWEST DISCIPLINES
TO HIT THE WORLD OF SCIENCE,
AND IT'S CALLED ASTROBIOLOGY.
AND IT'S NOT JUST THE SCIENCE CONCERNED WITH LIFE IN SPACE
OR EVEN THE STUDY OF LIFE ON EARTH.
IT'S MORE THAN THAT.
WE ALL SEEM TO KNOW IF SOMETHING IS ALIVE OR NOT,
BUT TRY COMING UP WITH A DEFINITION
THAT EVERYONE IN THE SCIENTIFIC COMMUNITY CAN AGREE ON.
ASTROBIOLOGY ISN'T SO MUCH THE SEARCH FOR LIFE
AS IT IS THE SEARCH FOR ANSWERS.
ASTROBIOLOGISTS USE THREE FUNDAMENTAL QUESTIONS
THAT HELP THEM GATHER INFORMATION
ABOUT OUR PLACE IN THE UNIVERSE:
WHERE DO WE COME FROM?
IS THERE SOMETHING ELSE LIKE US?
WHERE ARE WE GOING?
SO HOW DO WE START LOOKING FOR ANSWERS?
A GOOD PLACE TO START IS TO TAKE A LOOK
AT WHAT WE KNOW ABOUT LIFE HERE ON EARTH.
WE KNOW THAT WATER IS ESSENTIAL FOR LIFE ON OUR PLANET.
EVERYTHING FROM MAMMALS TO MICROBES
RELIES ON WATER IN ONE WAY OR ANOTHER.
NOW, FINDING WATER ON ANOTHER PLANET
CERTAINLY ISN'T CONCRETE PROOF THAT LIFE EXISTS,
BUT IT SURE INCREASES THE ODDS OF FINDING IT.
LOOKING AT EARTH AGAIN FOR CLUES,
WE KNOW THAT PROKARYOTES
ARE OUR PLANET'S MOST ABUNDANT INHABITANTS.
THERE ARE MORE OF THESE LITTLE GUYS
THAN YOU CAN EVEN IMAGINE.
AND THEY ARE FOUND NEARLY EVERYWHERE,
INCLUDING INHOSPITABLE ENVIRONMENTS
WITH EXTREME TEMPERATURES, pH VALUES,
RADIATION LEVELS, OR EVEN HIGH LEVELS OF TOXIC MATERIALS.
BECAUSE OF THESE FACTORS, SCIENTISTS HAVE AN INKLING
THAT IF THEY FIND LIFE OUT IN THE COSMOS,
IT WILL BE PROKARYOTIC IN NATURE,
LIKE BACTERIA OR SINGLE-CELL ORGANISMS.
THERE ARE EVEN PLACES IN OUR OWN SOLAR SYSTEM
WHERE SCIENTISTS BELIEVE LIFE
MAY HAVE THE ENVIRONMENT NECESSARY TO EXIST.
CAROLYN BRINKWORTH, A NASA SCIENTIST,
CAN TELL YOU A LITTLE BIT MORE.
- YOU KNOW, OUR OWN SOLAR SYSTEM
COULD BE A GREAT PLACE FOR LOOKING FOR LIFE.
WE'VE THOUGHT BEFORE THERE MAY BE LIFE ON MARS,
BUT WE'RE REALLY NOT ENTIRELY SURE.
WE THINK THERE USED TO BE LIQUID WATER THERE,
WHICH MEANS THAT THERE MAYBE
USED TO HAVE BEEN SOMEWHERE FOR LIFE TO EXIST,
BUT NOW MARS IS QUITE DRY
EXCEPT FOR UNDERNEATH THE SURFACE.
SO IF WE DO FIND LIFE ON MARS, IT'LL BE TINY LITTLE BACTERIA,
AND IT'LL BE BURIED UNDER THE SURFACE.
ANOTHER GREAT PLACE FOR LOOKING FOR LIFE, THOUGH,
IS ONE OF THE MOONS OF JUPITER WHICH IS CALLED EUROPA,
AND EUROPA, WE THINK, HAS A LIQUID WATER OCEAN
WHICH IS COVERED BY AN ICY SHELL.
AND WE'RE FAIRLY CONVINCED
THAT IT'S LIQUID UNDERNEATH THERE
BECAUSE OF CRACKS THAT WE SEE APPEARING IN THE ICE.
AND WHAT HAPPENS IS, AS EUROPA GOES AROUND JUPITER,
IT'S SQUASHED AND STRETCHED IN THE GRAVITATIONAL FIELD,
AND WE THINK THAT THIS IS WARMING UP
THE WATER UNDERNEATH THE ICE AND KEEPING IT LIQUID,
SO IT'S POSSIBLE WE COULD GO THERE
AND MAYBE FIND LIFE ON EUROPA.
WE NEED TO GO LOOK.
- NEW DISCOVERIES FORCE ASTROBIOLOGISTS
AND OTHER SCIENTISTS
TO ADDRESS THEIR OWN ASSUMPTIONS ABOUT LIFE.
THE MORE WE LEARN, THE MORE QUESTIONS WE HAVE.
ONE OF SATURN'S MOONS, TITAN,
HAS SCIENTISTS QUESTIONING WHAT WE KNOW ABOUT LIFE.
LET'S CHECK IN WITH DR. JAMES GREEN,
DIRECTOR OF PLANETARY SCIENCE FOR NASA.
- TITAN, WHAT A FABULOUS MOON OF SATURN.
BUT THIS MOON IS ENORMOUS.
IT IS BIGGER THAN THE PLANET MERCURY.
IF WE WERE TO PULL IT OUT
OF SATURN'S GRAVITATIONAL INFLUENCE
AND HAVE IT ORBIT THE SUN INSTEAD,
WE WOULD CALL IT A PLANET.
IT HAS AN ATMOSPHERE.
IT HAS LIQUID METHANE ON ITS SURFACE.
THINK ABOUT THAT.
IT IS THE ONLY OTHER OBJECT BESIDES THE EARTH
THAT HAS A LIQUID ON ITS SURFACE.
INSTEAD OF WATER, LIKE IT IS ON EARTH,
IT HAS METHANE LAKES.
RIGHT NOW, WE'VE COUNTED MANY OF THOSE.
WELL OVER 200 METHANE LAKES EXIST ON TITAN.
WE'VE ALSO LOOKED AT ITS HYDROLOGICAL CYCLE,
AND INDEED, WE SEE A PROCESS
OF EVAPORATION, CONDENSATION, AND RAIN.
IT IS RAINING METHANE RIGHT NOW
ON THE SOUTHERN HEMISPHERE OF TITAN.
- COULD LIFE EXIST HERE?
PERHAPS LIQUID METHANE PLAYS A SIMILAR ROLE
TO LIFE-FORMS ON TITAN
AS LIQUID WATER DOES TO LIFE-FORMS ON EARTH.
- JUST TO ME, SEEING THE POTENTIAL
OF STUFF THAT'S OUT THERE--
I MEAN, WE HAVE GONE FROM ONLY KNOWING ABOUT OUR OWN PLANET
TO KNOWING ABOUT PRETTY MUCH EVERYTHING ELSE IN THE UNIVERSE,
AND WE'RE STILL EXPLORING.
WE'RE ALWAYS PUSHING THESE BOUNDARIES, YOU KNOW.
WE'RE DISCOVERING MORE AND MORE AND MORE THINGS,
AND WE'RE ALWAYS ON THE CUTTING EDGE OF FINDING NEW THINGS.
I WOULD LIKE TO KNOW WHETHER THERE ARE
HABITABLE PLANETS OUT THERE.
I THINK THERE PROBABLY ARE.
I WOULD REALLY, REALLY, REALLY LIKE
TO FIND LIFE IN THE UNIVERSE.
I THINK THAT WOULD BE INCREDIBLE.
JUST THE CHANCES OF FINDING IT,
I MEAN, HOW INCREDIBLE WOULD THAT BE
IF WE FOUND LIFE ON ANOTHER PLANET?
THAT'S JUST COMPLETELY REVOLUTIONARY.
IT'S MIND-BLOWING IF WE COULD FIND THAT.
YEAH, JUST TO KNOW THAT WE'RE NOT ALONE IN THE UNIVERSE,
IT'S COMPLETELY MIND-BLOWING.
- NEW INNOVATIONS IN TECHNOLOGY AND ENGINEERING
DRIVE NEW DISCOVERIES IN SCIENCE,
WHICH LEAD TO THE NEED FOR NEW INSTRUMENTS
TO VERIFY THE RESULTS.
SO IT'S YOUR GENERATION, YOU,
THAT WILL BE LEADING THIS QUEST FOR LIFE
AND POTENTIALLY ANSWERING ONE OF HUMANKIND'S
MOST ASKED QUESTIONS: "ARE WE ALONE?"
THAT'S IT FOR NOW.
THANKS FOR WATCHING. I'M KAJA DUNN.
CATCH YOU NEXT TIME ON "NASA LAUNCHPAD."