>> FOR THOUSANDS OF YEARS,
MANKIND HAS WONDERED
"ARE THERE PLANETS AROUND
OTHER STARS?
IS THERE LIFE OUT THERE?"
BUT WE DIDN'T KNOW.
WE DIDN'T KNOW IF THERE WERE
ANY PLANETS AROUND OTHER STARS.
>> ZERO AND LIFTOFF
OF THE DELTA TWO ROCKET
WITH KEPLER, ON A SEARCH
FOR PLANETS IN SOME WAY
LIKE OUR OWN.
>> BEFORE THE LAUNCH OF KEPLER,
MOST OF THE PLANETS
WE KNEW ABOUT WERE REALLY
BIG PLANETS, LIKE JUPITER.
BUT KEPLER WAS SO SENSITIVE,
THAT WE STARTED FINDING
SMALLER AND SMALLER PLANETS.
>> WE DISCOVERED PLANETS
SMALLER THAN HAD EVER
BEEN DISCOVERED BEFORE
AND JUST, MANY OF THEM.
INDICATING THAT THE GALAXY
IS FULL OF PLANETS.
CRAZY WORLDS THAT WE
DIDN'T PREDICT, THINGS
THAT WE HADN'T IMAGINED.
WE FIND PLANETS ORBITING
SO CLOSE TO THEIR PARENT STAR
THAT THE STAR-FACING SIDE
HAS TEMPERATURES IN EXCESS
OF THAT REQUIRED TO MELT IRON.
THESE PLANETS HAVE
AN ENTIRE HEMISPHERE
THAT'S LIKE A LIQUID OCEAN.
BUT IT'S NOT AN OCEAN OF WATER.
IT'S AN OCEAN OF MOLTEN ROCK.
WE SEE PLANETS THAT ARE
ORBITING NOT ONE BUT TWO STARS.
THAT IS, IF YOU LOOK IN
THE EAST YOU WOULD SEE
NOT ONE STAR RISE BUT TWO.
>> ALMOST ALL THE ASTRONOMERS
THAT I KNOW GREW UP
READING SCIENCE FICTION.
THAT'S WHY A LOT OF THEM
GOT INTO THE BUSINESS OF
LOOKING FOR PLANETS
IN THE FIRST PLACE.
TO FIND OUT IF ANY OF
THIS, YOU KNOW, FANTASTIC
SPECULATION THAT INSPIRED US,
COULD BE TRUE.
AND NOW WE FIND OUT THAT,
YEAH, IT COULD BE TRUE.
>> WE LEARNED FROM KEPLER
THAT THE MOST COMMON TYPES
OF PLANETS IN THE GALAXY
ARE UNLIKE THE PLANETS
IN OUR OWN SOLAR SYSTEM.
THESE WORLDS ARE
INTERMEDIATE IN SIZE
BETWEEN THE EARTH AND NEPTUNE,
BUT WE'RE NOT EXACTLY SURE
WHAT THEY'RE MADE OF.
>> WHAT ARE THE THINGS
THAT WE KNOW NOW,
THAT WE DIDN'T KNOW THEN?
I MEAN, THINGS LIKE PLANETS
ARE UBIQUITOUS.
PLANETS ARE DIVERSE.
THE STARS THAT WE FIND
PLANETS AROUND ARE DIVERSE.
THE SYSTEMS THAT PLANETS
LIVE IN VARY WIDELY.
>> IT WAS BREATH-TAKING TO SEE
ALL THE PLANETS COME ROLLING IN
FROM THIS EXQUISITE DATA
OVER THE YEARS THAT
WE WERE COLLECTING DATA
WITH KEPLER.
IN THE END, WE FOUND
DOZENS OF SMALL, POTENTIALLY
ROCKY WORLDS ORBITING IN
THE "GOLDILOCKS ZONE"
OF THEIR STARS.
THAT DISTANCE AT WHICH YOU
COULD HAVE LIQUID WATER POOLING
ON THE SURFACE OF THE PLANET,
CAPABLE OF SUPPORTING
LIFE AS WE KNOW IT.
>> THE SCIENCE VALUE OF
THE COLLECTED DATA SPANS
ALMOST EVERY FIELD OF ASTRONOMY
AND PLANETARY SCIENCE.
IT REVOLUTIONIZED NOT JUST
EXOPLANETS, NOT JUST STARS,
BUT A LARGE NUMBER OF
THE SCIENTIFIC FIELDS
OF ASTRONOMY TODAY.
>> THERE WAS ONE SUMMER WHERE
I WORKED AT AN OBSERVATORY
AND I WOULD GO OUTSIDE AT NIGHT
AND LOOK UP AT THE STARS
AND JUST BE BLOWN AWAY
AT HOW VAST SPACE WAS.
AND I ACTUALLY FELT
A LITTLE LONELY.
AND WHEN I GO OUT AND I LOOK
AT THE NIGHT SKY NOW,
RATHER THAN BEING AWESTRUCK
BY THE VASTNESS, I'M AWESTRUCK
BY THE POSSIBILITY.
>> THERE AREN'T THAT
MANY OPPORTUNITIES IN LIFE
WHERE YOU GET TO PARTICIPATE
IN A PROJECT AS IMPORTANT
AS KEPLER IS THAT ANSWERS
SUCH A FUNDAMENTAL QUESTION
THAT WE'VE BEEN ASKING
OURSELVES FOR SO LONG.
NOW WE KNOW WHEN WE LOOK UP
INTO THE NIGHT SKY
THAT EVERY STAR WE SEE HAS,
ON AVERAGE, AT LEAST ONE PLANET.
AND THAT MANY OF THOSE PLANETS
ARE SIMILAR IN SIZE TO THE EARTH
AND A CHANCE FOR LIFE
AS WE KNOW IT ELSEWHERE.
>> SEARCHING FOR LIFE ELSEWHERE
IS ONE OF THE KEY THEMES
THAT DRIVE OUR SCIENCE PORTFOLIO
AND AT THE CENTER OF THAT
IS KEPLER.
NEW MISSIONS LIKE
THE TRANSITING EXOPLANET
SURVEY SATELLITE, TESS,
AND THE JAMES WEBB SPACE
TELESCOPE WILL BUILD ON
KEPLER'S SUCCESS AND TAKE
OUR SEARCH FOR LIFE
TO NEW HEIGHTS.
>> IT HAS BEEN EXTREMELY
GRATIFYING TO SEE THE DATA
COME BACK FROM THE MISSION
AND SHOW WHAT WE WANTED TO KNOW,
GIVE US THE ANSWER.
MANY STARS HAVE PLANETS,
A LOT OF THESE PLANETS
ARE EARTH-SIZED.
THAT'S KEPLER'S LEGACY.
THIS NEW KNOWLEDGE
THAT WE HAVE ABOUT PLANETS
AROUND OTHER STARS.