>>> NASA'S JET PROPULSION
LABORATORY PRESENTS VON KARMAN
LECTURE, FOR THOSE WHO ARE
EXPLORING OUR PLANET, SOLAR
SYSTEM AND ALL THE LIFE BEYOND.
>> WOW.
WE PACKED THE HOUSE TONIGHT.
HOW IS EVERYBODY DOING?
EXCELLENT.
THEY FOR COMING TO ATTEND THESE
WONDERFUL LECTURES.
THE CASSINI MISSION ON A
COOPERATIVE UNDERTAKING BY NASA
AND THE EUROPEAN AND ITALIAN
SPACE AGENCIES HAS
REVOLUTIONIZED OUR UNDERSTANDING
OF SATURN, ITS RINGS AND AMAZING
ASSORTMENT OF MOONS AND THE
DYNAMICS MAGNETIC ENVIRONMENT.
THE ASTONISHING DISCOVERIES
CONTINUE TO THIS DAY AND WE
CAN'T WAIT TO SEE WHAT HAPPENS
WHEN CASSINI REPEATEDLY DIVES
BETWEEN THE INNER MOST RING AND
THE TOP OF SATURN'S ATMOSPHERE
DURING THE FINAL SIX MONTHS
STARTING IN APRIL 2017 BEFORE
FINALLY PLUNGING INTO SAT YOU
WERE'S ATMOSPHERE IN SEPTEMBER.
TONIGHT, WE HAVE TWO GUESTS WHO
WILL PRESENT HIGHLIGHTS,
EXPECTATION, CHALLENGES AND THE
PROMISE OF CASSINI'S FINAL YEAR.
DR.
EARL MAIZE IS THE MANAGER OF
THE CASSINI PROGRAM.
HE BEGAN HIS CAREER WORKING ON
THE NAVIGATION AND ENGINEERING
TEAMS FOR THE GALILEO MISSION TO
JUPITER.
HE TRANSFERRED TO CASSINI AS THE
OPERATIONS MANAGER AND THEN
DEPUTY PROJECT MANAGER.
HE LEFT THE PROJECT FOR EIGHT
YEARS TO HOLD MANAGEMENT
POSITIONS IN AVIONICS, THEN
RETURNED TO CASSINI AS THE
PROGRAM MANAGER IN JANUARY OF
2013.
DR.
LINDA SPILKER IS THE CASSINI
PROJECT SCIENTIST.
AND THE CO INVEST GATOR ON THE
TEAM.
SINCE JOINING JPL 40 YEARS AGO
HER FIRST AND ONLY OUT OF
COLLEGE JOB BY THE WAY SHE'S
WORKED ON THE VOYAGER PROJECT,
CASSINI PROJECT AND CONDUCTED
INDEPENDENT RESEARCH ON THE
ORIGIN AND EVOLUTION OF
PLANETARY RING SYSTEMS.
SHE SUPPORTS CONCEPT STUDIES FOR
NEW MISSIONS TO THE OUTER
PLANETS.
SHE ENJOYS YOGA AND HIKING.
ESPECIALLY THROUGH HER FAVORITE
PARK, YOSEMITE, AND IS MARRIED
WITH THREE DAUGHTERS AND FIVE
GRANDCHILDREN.
UP FIRST TONIGHT, PERHAPS ONE OF
THE COOLEST GRANDMOTHERS EVER,
DR.
LINDA SPILKER.
>> THANKS, MARK.
A GREAT INTRODUCTION.
AS MARK INDICATED CASSINI HAS
TRULY REWRITTEN WHOLE TEXTBOOKS
ON THE SATURN SYSTEM.
FROM THE PLANET ITSELF, TO THE
COMPLEX RING SYSTEM, TO THESE
AMAZING AND ASTONISHING MOONS
THAT COME IN ALL SHAPES AND
SIZES.
THEN THE GREAT MAGNETIC FIELD
THAT SURROUNDS THE PLANET
ITSELF.
I'M GOING TO COVER SOME OF THE
HIGHLIGHTS OF CASSINI'S JOURNEY
IN THE SATURN SYSTEM.
HER 12 YEAR VOYAGE AROUND
SATURN.
AND THEN EARL IS GOING TO TALK
ABOUT THE GRAND FINALE.
THOSE LAST PRECIOUS ORBITS OF
CASSINI LIKE A BRAND-NEW
MISSION, AND THEN THOSE FINAL
MOMENTS WITH CASSINI.
NOW, IF YOU LOOK AT THE PICTURE
BEHIND ME, THIS IS ONE OF MY
VERY FAVORITE MONTAGES FROM
CASSINI.
THIS YOU CAN SEE ALL OF THE
MAJOR RINGS OF THE SATURN
SYSTEM.
AND IT'S A UNIQUE GEOMETRY, THE
PLANET ITSELF IS COVERING UP THE
SUN, ALLOWING CASSINI'S
SENSITIVE CAMERAS AND DETECTORS
TO THE MOSAIC BACK LIT VIEW.
LIKE LOOKING THROUGH A DUSTY
WINDSHIELD AND THESE PARTICLES
BRIGHTEN UP AND YOU CAN SEE
THEM.
WHAT YOU SEE IS THE PLANET
ITSELF AND THE MAIN RING SYSTEM.
THAT FAINT RING IS THE G-RING.
THAT BEAUTIFUL BLUE RING IS
SATURN'S E-RING.
IT'S CREATED BY TINY ICY
PARTICLES THAT COME FROM THE
SOUTH POLE TO GO ON TO FORM THE
RING THAT FILLS IN ENCELADUS'S
ORBIT AND THIS GOES OUT TO THE
ORBIT OF TITAN, ONE OF THE
DISTANT MOONS OF SATURN.
IF YOU LOOK AT SATURN YOU'LL
NOTICE A WHITE RING AROUND THE
PLANET.
THIS IS WHERE THE SUNLIGHT IS
REFRACTED THROUGH THE TOP OF THE
ATMOSPHERE.
INTO YOUR EYES.
IT'S SO BEAUTIFUL BECAUSE WHEN
YOU LOOK AT THIS RING AROUND SAT
YOU WERE, YOU'RE SEEING EVERY
SUNRISE AND SUNSET ON THE PLANET
AT THE VERY SAME TIME.
AND YOU'RE LOOKING AT THE DARK
SIDE OF SATURN AND YET SOMETHING
IS LIGHTING UP THE NIGHT SIDE.
WHAT'S LIGHTING UP THE NIGHT
SIDE IS ACTUALLY LIGHTS COMING
FROM SATURN'S RINGS.
SO THE SUNLIGHT HITS THE RINGS
ON ONE SIDE AND IT THEN REFLECTS
ON TO THE NIGHT SIDE OF SATURN.
ONE OF THE MANY INCREDIBLE
IMAGES THAT HAVE COME BACK FROM
THE CASSINI MISSION.
NOW, I'M OFTEN ASKED WHY DO WE
EXPLORE SPACE?
WHY DO WE SEND ROBOTIC
EMISSARIES OUT LIKE CASSINI?
WHAT ARE SOME OF THE GRAND
QUESTIONS WE HOPE TO ANSWER.
AND CASSINI ADDRESSES TWO OF
THOSE.
THESE ARE SOMETHING THAT WE'RE
IN A SURVEY FOR PLANETARY
SCIENCE.
WE DO THESE ONCE EVERY TEN
YEARS.
THE FIRST GRAND QUESTION IS ARE
WE ALONE IN THE UNIVERSE?
HAS LIFE ORIGINATED SOMEWHERE
OTHER THAN EARTH, PERHAPS IN OUR
OWN SOLAR SYSTEM?
HOW DID LIFE ORIGINATE ON THE
EARTH?
ANOTHER GRAND QUESTION IS POW
DID THE SOLAR SYSTEM AND THE
EARTH WITHIN IT COME TO BE?
HOW IS IT EVOLVING AND WHERE IS
IT HEADED?
BY STUDYING THE PLANETS IN OUR
SOLAR SYSTEM WE CAN LEARN ABOUT
HOW OUR SOLAR SYSTEM FORMED, HOW
THE PLANETS MAY HAVE MIGRATED AS
THE SYSTEM EVOLVED AND WHERE WE
MIGHT BE HEAD AND IT'S GOOD
ANALOGY FOR OTHER SYSTEMS AROUND
OTHER STARS.
HERE'S -- I WANT TO GO BACK
BRIEFLY HERE AND SHOW YOU THESE
ARE THE EIGHT PLANETS IN OUR
SOLAR SYSTEM.
SATURN IS THE SIXTH PLANET OUT
FROM THE SUN.
THE SECOND LARGEST PLANET.
IT TAKES 30 YEARS TO CIRCLE THE
SUN A SINGLE TIME.
NOW SATS YOU WERE IS INDEED
HUGE.
THE SECOND LARGEST PLANET.
THIS SHOWS THE EARTH AND THE
MOON TO SCALE AND THE DISTANCE
IN BETWEEN THEM.
AND SO YOU CAN SEE THAT SATURN
WOULD JUST FIT IN BETWEEN THE
EARTH AND THE MOON.
AND IF THE EARTH WERE A TINY
MARBLE IT WOULD TAKE 764 EARTHS
TO FILL UP THE VOLUME OF SATURN.
SO TRULY A GIANT PLANET.
AND WHAT YOU'RE SEEING ARE JUST
CLOUD TOPS.
SATURN DOESN'T HAVE A SOLID
SURFACE LIKE THE EARTH.
MOSTLY HYDROGEN AND HELIUM.
MAYBE A TINY ROCKY CORE ABOUT
THE SIZE OF THE EARTH IN THE
CENTER.
NOW HERE'S AN OVERVIEW OF THE
CASSINI MISSION.
CASSINI WAS LAUNCHED FROM THE
EARTH IN 1997.
WE USED GRAVITY ASSIST TO VENUS.
ONE FLY BY BY THE EARTH, ONE OF
JUPITER AND ARRIVING AT SATURN
IN JULY OF 2004.
ORIGINALLY CASSINI WAS FUNDED BY
THE FOUR YEAR PRIME MISSION AND
WE FOUND WE HAD ENOUGH FUEL AND
A HEALTHY SPACECRAFT THAT WE HAD
TWO EXTENDED MISSIONS.
THE EQUINOX MISSION WHERE THE
SUN WAS SHINING ON SATURN'S
EQUATOR AND THEN A SEVEN-YEAR
SOLSTICE MISSION.
AND NORTHERN SUMMER SOLSTICE
WILL BE IN MAY OF 2017 AND THE
MISSION WILL LAST JUST PAST
THAT.
ENDING IN SEPTEMBER OF 2017.
YOU CAN SEE THERE AT THE END IN
THE GREEN BOX WHAT WE CAN CALL
THE PROXIMAL ORBITS OR GRAND
FINALE ORBITS.
THEY'RE SHOWN ABOVE HIGHLIGHTED
IN THIS BOX AND THIS WHOLE
MISSION IS SHOWN AGAINST THE
30-YEAR ORBITAL PERIOD FOR
SATURN.
AT THE END OF 13 YEARS WE'LL
HAVE BEEN IN ORBIT IN THE SATURN
SYSTEM FOR ALMOST TWO SEASONS.
THEY CHANGE VERY, VERY SLOWLY AT
SATURN.
AND RIGHT NOW, CASSINI IS ALMOST
TO THAT GREEN BOX.
WE'RE GOING UP IN INCLINATION
AND WE'RE GETTING READY FOR OUR
FINAL SET OF ORBITS.
THIS IS ANOTHER VIEW OF THE
CASSINI MISSION BY YEAR.
YOU CAN LOOK ACROSS THE TOP BAR.
IT SHOWS THE NUMBER OF ORBITS
AND THE SHAPES OF THOSE ORBITS.
THEN YOU CAN SEE THAT BY THE END
OF THE MISSION WE'LL HAVE 127
FLY BYES OF THE GIANT MOON
TITAN.
TITAN IS LIKE A GIANT ROCKET
ENGINE.
EVERY TIME WE FLY BY TITAN IT'S
LIKE EXPENDING AS MUCH AS WE
WENT INTO SATURN ORBIT.
WE HAVE HAD 23 FLY BYES OF
ENCELADUS AND IN THE FIRST FOUR
YEARS WE HAD THREE.
WE DISCOVERED ENCELADUS WAS SO
INTERESTING THAT IT WAS RESHAPED
OUR THINKING FOR THE EXTENDED
MISSION AND WE ADDED 20 MORE FLY
BYES OF ENCELADUS.
WE HAVE 15 FLY BYES OF THE OTHER
SATELLITES AND THEN THE SEASONS
ARE CHANGING FROM NORTHERN
WINTER TO NORTHERN SUMMER OVER
THE COURSE OF THE CASSINI
MISSION.
OF COURSE THE PROXIMAL OR GRAND
FINALE ORBITS AT THE END AND
EARL WILL BE TALKING ABOUT THOSE
IN MORE DETAIL.
THIS IS A CASSINI ORBITER AND
THE HUYGENS PROBE.
YOU CAN SEE A GREAT MODEL OVER
IN THE CASSINI SPACECRAFT.
CASSINI IS ABOUT 22 FEET TALL.
THAT ANTENNA AT THE TOP IS 13
FEET IN DIAMETER.
COMPARE TO BELIEVE THE VOYAGER
AN TEN YA YOU CAN SEE OVER HERE.
YOU CAN SEE PEOPLE FOR REFERENCE
AND FULLY FUELED, CASSINI
WEIGHED SIX TONS AND ABOUT HALF
OF THAT WAS FUEL THAT WE SPENT
ABOUT A THIRD OF THAT JUST TO GO
INTO ORBIT AROUND SATURN.
THE HUYGENS PROBE WAS PROVIDED
BY THE EUROPEAN SPACE AGENCY AND
IT WAS SPECIFICALLY DESIGNED
WITH THE GOAL OF BEING THRUST
INTO SATURN AND TITANS
ATMOSPHERES.
PARACHUTING DOWN AND LANDING ON
THE SURFACE OF TITAN.
NOW CASSINI ISN'T JUST A
SPACECRAFT THAT'S MADE UP OF
METAL AND BOLTS AND BITS AND
PIECES BUT THIS IS KIND OF MY
VIEW OF CASSINI.
I SEE CASSINI AS MADE UP OF ALL
THE PEOPLE THAT ARE ON HER TEAM.
THE SCIENTISTS, THE ENGINEERS,
THE SUPPORT STAFF.
AND IN A WAY CASSINI REPRESENTS
ALL OF THEIR HOPES AND DREAMS.
ALL OF THE THINGS THAT WE WANT
TO ACCOMPLISH.
IN OUR TIME FRAME, PICTURE
MYSELF THERE WITH CASSINI IN THE
SATURN SYSTEM AS GET BACK SOME
OF THOSE WONDERFUL IMAGES OR
SPECTRA OR DATA OF THE
INCREDIBLE PLACES.
I ALMOST FEEL LIKE I'M RIGHT
THERE LOOKING THROUGH CASSINI'S
EYES AND WATCHING AS SHE
COLLECTS HER DATA AND FEEL VERY
PROUD TO BE A PART OF THIS
INCREDIBLE MISSION.
NOW ON TO SOME OF THE SCIENCE.
THIS IS THE TINY MOON ENCELADUS
AND ENCELADUS IS ONLY 300 MILES
ACROSS.
ENCELADUS WOULD FIT BETWEEN LOS
ANGELES AND SAN FRANCISCO SO
IT'S A VERY TINY MOON.
YET, A VERY INTERESTING ONE.
WHEN WE SAW IT WITH VOYAGER WE
SAW A VERY BRIGHT ICY SURFACE.
GENERALLY IN THE SOLAR SYSTEM
SOMETHING BRIGHT MEANS IT'S
YOUNG.
YOU HAVEN'T HAD A CHANCE TO
BUILD UP TO POLLUTION FROM THE
MICROMETEORITE BOMBARDMENT.
AS YOU GO SOUTH VERY FEW
CRATERS.
IN FACT, NO CRATERS.
AT THE SOUTH POLE OF ENCELADUS.
YOU CAN SEE FOUR TIGER STRIPE
FRACTURES.
ALEXANDRIA, CAIRO AND DAMASCUS.
INTERESTING NAMES AND THE
FRACTURES WERE SOMETHING THAT
WERE IN DARKNESS WHEN THE
VOYAGER SPACECRAFT FLEW THROUGH
THE SPACE SYSTEM.
WE DIDN'T KNOW UNTIL WE HAD
CASSINI.
OUR FIRST SPACECRAFT IN 2005,
OUR MAGNETOMETER TEAM SAID
THERE'S SOMETHING GOING ON WITH
THE ENCELADUS.
THE MAGNETIC LINES DON'T GO DOWN
TO THE ICY SURFACE LIKE NORMAL.
INSTEAD IT'S LIKE A COMET.
THOSE FIELD LINES ARE STANDING
OFF, SOMETHING GOING ON IN THE
SOUTHERN HEMISPHERE.
SO WE HAVE A THOUSAND KILOMETER
FLY BY, AND THEY SAID GO CLOSER.
WE CAN GET BETTER DATA.
WE WENT CLOSER AND TRAINED THE
OTHER INSTRUMENTS ON ENCELADUS.
HERE THIS IS WITH THE COMPOSITE
SPECTROMETER, THEY FOUND THAT
THE ENCELADUS SOUTH POLE WAS
HOT.
IT WAS ABOUT 100 DEGREES HOTTER
THAN THE REST OF ENCELADUS AND
ENCELADUS WERE FROZEN SOLID IT
WAS MUCH HOTTER THAN IT SHOULD
BE.
IN LOOKING MORE CLOSELY THAT
HEAT LINED UP WITH THOSE TIGER
LIKE FRACTURES.
SO IT WAS A PUZZLE.
WE HAD A STAR GOING BEHIND THIS
REGION.
WE LOOKED AT THESE TIGER STRIPES
IN MORE DETAIL.
ON THE VARIOUS FLY BYES.
HERE'S THE TIGER STRIPE IT'S
ABOUT A MILE OR SO ACROSS.
TYPICALLY ABOUT 100 MILES WIDE.
IT'S JUST THIS LARGE GASH.
FOUR OF THEM IN THE SOUTH POLE.
YOU CAN SEE WHAT LOOKS LIKE A
FROSTED SIDE ON THE LEFT-HAND
SIDE THERE.
WE WONDERED WHAT COULD BE GOING
ON WITH THE TIGER STRIPES.
WE ALSO HAD IMAGES AND THE
ANSWER IT WAS VERY CLEAR.
THERE ARE JETS OF MATERIAL,
WATER VAPOR.
WATER ICE PARTCALS -- PARTICLES
SHOOTING OUT OF THE FRACTURES.
HERE'S VIEW OF THE JETS COMING
OUT GOING IN ALL DIFFERENT
DIRECTIONS.
CONTINUOUSLY GOING OFF EVER
SINCE CASSINI ARRIVED AT SATURN.
WE HAVE BEEN WATCHING ENCELADUS.
SO NOT ONLY DO YOU GET WATER
VAPOR AND WATER ICE COMING OUT,
YOU HAVE THINGS LIKE AMMONIA,
METHANE, CARBON DIOXIDE.
YOU HAVE MANY OF THE KEY
INGREDIENTS THAT YOU MIGHT NEED
TO FIND LIFE COMING OUT OF THESE
JETS ON ENCELADUS.
AND PART OF OUR -- THE GOAL OF
OUR FLY BYES IS ACTUALLY TO FLY
THROUGH THIS MATERIAL.
AND IN OCTOBER WE CAME WITHIN 50
KILOMETERS OF ENCELADUS'S
SURFACE RIGHT UNDER THE SOUTH
POLE.
AND IT GAVE US A CHANCE TO
ESSENTIALLY TASTE AND SMELL
THOSE PARTICLES, FIGURE IT WHAT
THEY WERE MADE OF AND TRY AND
FIGURE OUT THE ACTIVITY INSIDE
OF ENCELADUS.
HERE'S ANOTHER VIEW OF THE ICY
JETS THIS IS BACK LIT VIEW
SIMILAR TO WHAT YOU SAW IN THE
SATURN IMAGE.
YOU CAN SEE THE SUN LIGHT
THROUGH EACH OF THE JETS AND WE
FOUND IN THE PARTICLES THAT SOME
OF THOSE WERE SALTY.
IT'S -- THERE'S A GLOBAL OCEAN
UNDERNEATH ENCELADUS'S ICY
CRUST.
IT'S AS THOUGH THEY WERE FROZEN
SEA SPRAY.
THEY CONTAINED SODIUM AND
POTASSIUM SALT.
WE KNOW THE PH OF THE OCEAN IS
VERY SIMILAR TO THE OCEANS HERE
ON THE EARTH.
SO VERY INTERESTING FINDING IN
THE PARTICLE DATA.
THIS IS AN INTERESTING VIEW.
THIS IS ANOTHER ENCELADUS.
THIS IS A FOUNTAIN AT VERSAILLES
IN THE GARDENS THERE AND IT'S HE
HAD A RUN-IN WITH HIS
GRANDDAUGHTER SO HE'S BURIED
UNDER MOUNT ETNA.
HE'S PROTESTING THE 82 FOOT HIGH
GEYSER OF WATER.
WHO KNEW IN THE '60s AND '70s
THAT ENCELADUS WOULD BE DOING
SOMETHING LIKE THIS?
HERE'S AN ARTIST CONCEPT OF WHAT
MIGHT BE GOING ON.
YOU HAVE THE LIQUID WATER OCEAN
UNDERNEATH THE ICY CRUST.
THAT CARBON DIOXIDE MIGHT BE
LIKE SHAKING UP A CHAMPAGNE
BOTTLE.
YOU POP THE CORK AND PERHAPS
THAT'S THE ENERGY THAT'S THERE
TO RAISE THAT WATER VAPOR AND
ICY PARTICLES DO SEND THEM
CONTINUOUSLY INTO SPACE.
NOW, MOST OF THE MATERIAL FALLS
BACK ON TO THE SURFACE OF
ENCELADUS.
THE PARTICLES ARE TOO LARGE AND
THEY FALL BACK AND IT'S LIKE
IT'S SNOWING.
IF YOU COULD STAND NEAR A TIGER
STRIPE UNDERNEATH IT, PUT OUT
YOUR HAND.
IT'S LIKE IT'S SNOWING ON
ENCELADUS.
MAYBE A FUTURE VACATION
DESTINATION.
YOU KNOW?
WHO KNOWS.
BUT SOME OF THE TINIEST GRAINS
ESCAPE INTO SPACE.
THERE THEY GO ON TO FORM THE
BEAUTIFUL E-RING YOU SAW IN
FIRST IMAGE.
YOU CAN SEE THE TINY BLACK DOT
THAT'S ENCELADUS.
UNDERNEATH IT IS THE BRIGHT
PLUME OF MATERIAL COMING OUT.
YOU CAN SEE WISPS AND TENDRILS
OF THEM FORMING THE E-RING.
THEY SPREAD THROUGHOUT THE
SYSTEM AND IF YOU TURNED OFF
ENCELADUS'S JETS IT MIGHT ONLY
TAKE 100 OR 200 YEARS UNTIL THE
E-RING IS GONE COMPLETELY.
SO THAT'S LIKE SORT OF A CLUE.
WE SEE THE E-RING.
WE KNOW THE JETS ARE GOING OFF
AT ENCELADUS.
THIS IS JUST AN ARTIST CONCEPT
OF THE INSIDE OF ENCELADUS.
WE KNOW IT'S DIFFERENTIATED,
THAT MEANS IT'S SEPARATED INTO
THE ROCKY CORE, A GLOBAL OCEAN
AND ICY CRUST.
WE HAVE FOUND THAT IN LOOKING AT
SOME OF OUR PARTICLE DATA THERE
ARE TINY GRAINS OF SILICA.
WE CALL THEM NANO SILICA GRAINS
WHAT'S UNIQUE ABOUT THEM, THEY
CAN ONLY FORM IN WATER THAT'S
NEAR BOILING.
SO WHAT WE THINK HAPPENS IS THAT
THE WATER GOES INTO THE ROCKY
CORE OF ENCELADUS.
IT'S HEATED UP THERE.
AND ENCELADUS IS KEPT WARM BY A
RESONANCE WITH ANOTHER MOON --
THAT'S ESSENTIALLY PULLAL --
PUMPING HEAT ENERGY INTO IT AND
IT ABSORBS THE SILICA.
WHEN THE SILICA COMES OUT
THROUGH THE HYDROTHERMAL VENTS,
HITS THE COLD WATER, THEY
CONDENSE INTO TINY PARTICLES.
THOSE PARTICLES ARE FROZEN INTO
THE PARTICLES THAT GO OUT INTO
SPACE.
SO THIS IS AN INDICATION THAT
THERE'S A POSSIBILITY OF
HYDROTHERMAL VENTS ON THE SEA
FLOOR OF ENCELADUS.
WE HAVE THE SAME KIND OF
HYDROTHERMAL VENTS ON THE SEA
FLOOR OF THE EARTH.
THIS IS ALONG THE MID OCEANIC
RIDGE IN THE ATLANTIC OCEAN.
IT IS VERY, VERY DEEP.
NO SUNLIGHT PENETRATES TO THAT
DEPTH.
THIS IS ILLUMINATED FROM THE
HEAD LIGHT OF THE SUBMARINE
LOOKING AT THIS PARTICULAR
EVENT.
HERE YOU HAVE SILICA AND
POTASSIUM AND OTHER MINERALS
THAT CONDENSE, FORMING WHAT
LOOKS LIKE SMOKE.
THESE ARE KNOWN AS WHITE SMOKERS
ON THE EARTH.
THERE'S ALSO SOMETHING A --
DEPENDING ON THE COMPOSITION,
BLACK SMOKERS AS WELL.
THEY'RE MORE IRON RICH.
WHAT'S INTERESTING HERE IN THE
DEEP, COLD OCEAN WHERE YOU HAVE
NO SUNLIGHT, THE ONLY HEAT
ENERGY AND NUTRIENTS ARE COMING
OUT OF THE VENTS.
YOU FIND AN AMAZING ARRAY OF
LIFE.
YOU FIND TINY CRABS, FIND TUBE
WORMS.
YOU FIND LITTLE TINY ANIMALS.
ALL SORTS OF LIFE IN AN ISLAND
AROUND THESE HYDROTHERMAL VENTS.
SO WE WONDER IF WE CAN FIND LIFE
IN OUR OWN OCEAN, PERHAPS MIGHT
THERE BE LIFE IN THE OCEAN OF
ENCELADUS?
SOME FACTORS THAT LIFE MIGHT
EXIST THERE INCLUDE A GLOBAL
SALTY OCEAN, PH VERY SIMILAR TO
OUR OWN.
A GLOBAL OCEAN PROBABLY FORMED
AT THE SAME TIME AS ENCELADUS.
THERE'S ORGANICS COMING TO THE
LIMIT OF THE INSTRUMENTS WE HAVE
TO DETECT THEM.
CARBON CHAINS UP TO C-6, C-7.
THEY'RE PROBABLY EVEN LONGER BUT
THAT'S THE CUTOFF OF THE
INSTRUMENTS WHAT WE CAN MEASURE.
HEAT ENERGY COMING FROM THE
HYDROTHERMAL VENTS OF THE FLOOR
AND BEST OF ALL IT'S GIVING US
FREE SAMPLES.
IT TURNS OUT WHEN WE LAUNCHED
CASSINI WE HAD NO IDEA THAT
THERE WOULD BE THE JETS OR VENTS
COMING OUT OF ENCELADUS.
SO WE DIDN'T CARRY THE
INSTRUMENTS TO LOOK AT THE FATTY
ACIDS OR LONG CHAIN MOLECULES TO
TELL US LIFE IS THERE.
THIS IS A WONDERFUL DESTINATION,
THIS OCEAN WORLD TO GO BACK TO
ENCELADUS.
AND TO KEEP EXPLORING AND ANSWER
THE QUESTION.
ARE WE ALONE IN THE UNIVERSE OR
PERHAPS MIGHT THERE BE LIFE IN
ENCELADUS'S OCEAN?
NOW, ANOTHER VERY INTERESTING
MOON IS SAT YOU WERE'S MOON
TITAN.
TITAN IS TEN TIMES BIGGER THAN
ENCELADUS.
AND IN FACT TITAN IS ABOUT THE
SIZE OF PLANET MERCURY.
IF TITAN HAD FORMED ANYWHERE
ELSE, IT WOULD BE A PLANET
INSTEAD OF A MOON.
NOW THIS WAS A VOYAGE OF A VIEW
OF TITAN.
WE JUST SAW THIS HAZY WORLD AND
WE COULDN'T SEE THROUGH TO THE
SURFACE.
SO AFTER THE VOYAGER FLY BYES IN
THE 1980s A GROUP OF SCIENTISTS
GOT TOGETHER AND SAID, YOU KNOW,
WE NEED TO START THINKING ABOUT
GOING BACK AND IT WAS BOTH U.S.
AND EUROPEAN SCIENTISTS AND THAT
WAS BASICALLY THE BIRTH OF THE
IDEA FOR WHAT BECAME THE CASSINI
MISSION.
NOW, TITAN HAS A DENSE
ATMOSPHERE, MADE MOSTLY OF
NITROGEN.
NO OXYGEN, BUT IT HAS METHANE IN
ITS ATMOSPHERE.
AND METHANE IS REALLY THE KEY AT
TITAN.
BECAUSE YOU SEE, METHANE PLAYS
THE ROLE WITH TITAN THAT WATER
PLAYS HERE ON THE EARTH.
THE METHANE CAN BE A GAS, IT CAN
BE A LIQUID, IT CAN FORM CLOUDS.
IT CAN RAIN ON TO THE SURFACE OF
TITAN.
BUT THE TEMPERATURE OF TITAN
SURFACE IS JUST RIGHT, WHERE YOU
COULD HAVE A LIQUID, A SOLID OR
A GAS OR A METHANE.
METHANE IS PROBABLY A PROBLEM
WITH THE SMOG ON TITAN.
YOU SEE THE METHANE GOES HIGH UP
IN THE ATMOSPHERE.
THE SOLAR PHOTONS BREAKS ITS
APART, THEY GROW INTO LARGER AND
LARGER CHAINS OF MOLECULES.
THAT FORMS HAZE VERY SIMILAR TO
THE SMOG THAT WE HAVE HERE ON
THE EARTH.
WHEN THE PARTICLES GROW LARGE
ENOUGH THEY ACTUALLY FALL DOWN
ON TO THE SURFACE OF TITAN.
NOW, THE HUYGENS PROBE WAS BUILT
TO GO THROUGH THE ATMOSPHERE,
LAND ON THE SURFACE AND REVEAL
THE SURFACE FOR THE FIRST TIME.
NOW, SO THIS IS AN ARTIST
CONCEPT OF THE HUYGENS PROBE.
YOU SEE IT COMING IN.
IT WAS RELEASED FROM CASSINI ON
DECEMBER 25th, 2004.
ENTERED INTO THE ATMOSPHERE AND
LANDED ON TITAN ON JANUARY 15th
OF 2005.
SO THE HEAT SHIELD BASICALLY
OBLATED AWAY, CARRYING AWAY THE
HEAT ENERGY.
ONCE THE PROBE HAD SLOWED DOWN
ENOUGH THEN THE PARACHUTE COULD
COME OUT.
FOR THE NEXT 2 1/2 HOURS THE
HUYGENS PROBE FLOATED DOWN TO
THE SURFACE OF TITAN, SOFTLY
LANDED ON THE SURFACE.
AND RETURNED DATA FOR ANOTHER
HALF HOUR.
CASSINI WAS THE RELAY SO AS THE
HUYGENS PROBE WAS FLOATING DOWN,
CASSINI WAS FLYING OVERHEAD,
COLLECTING THE DATA TO SEND BACK
TO THE EARTH.
REALLY AN AMAZING MISSION.
WITH HUYGENS WE DIDN'T KNOW WHAT
WE'D FIND.
WOULD WE LAND IN THE GLOBAL
OCEAN AS METHANE?
SO WE BUILT THE HUYGENS PROBE TO
FLOAT.
AT LEAST FOR A FEW MINUTES BUT
IT TURNS OUT THAT WE DIDN'T HAVE
TO WORRY ABOUT LANDING IN AN
OCEAN.
INSTEAD, HERE'S THE VIEW THAT WE
HAD WITH THE CAMERAS.
WE MEASURED NOT ONLY THE
PRESSURE, TEMPERATURE AND
COMPOSITION OF TITANS ATMOSPHERE
ON THE WAY DOWN, BUT THE CAMERAS
TOOK THESE PICTURES.
ABOUT 60 KILOMETERS ABOVE THE
SURFACE, THE HAZE FINALLY
STARTED TO CLEAR AND WE GOT A
VIEW OF THE SURFACE AND WE
STARTED TO SEE WHAT LOOKED LIKE
MOUNTAINS.
AS WE WENT ON OUR WAY DOWN, AND
IN FACT, THE HUYGENS PROBE
BECAME THE VERY FIRST OBJECT TO
LAND IN THE OUTER SOLAR SYSTEM,
LAND ON A BODY THE FURTHEST AWAY
FROM ANYTHING WE HAVE HAD
PREVIOUSLY.
HERE'S A VIEW OF THE SURFACE.
YOU CAN SEE ON THE LEFT MOST
PANEL THESE ARE ROUNDED ICY
PEBBLES THAT TELLS US THAT FLUID
HAS FLOWED IN THE REGION.
PROBABLY WE LANDED FROM THE DRY
LAKE BED.
WE HAD A LAMP YOU CAN SEE THE
SPOT FOR THE LAMP HERE TO GIVE
US AN IDEA OF WHAT THE COLOR
MIGHT BE OF THE SURFACE.
YOU CAN SEE THE ICY PEBBLES
HERE.
AND HERE'S A REALLY NEAT
COMPARISON.
THIS IS FROM OUR OWN MOON.
HERE'S A FOOTPRINT OF ONE OF THE
APOLLO ASTRONAUTS.
YOU CAN SEE THE ASTRONAUT IN THE
LITTLE FLAG UP HERE.
SO THIS IS SORT OF THE SAME VIEW
WE HAD ON TITAN.
AND WE ALSO COULD SEE ALL OF
THESE CHANNELS INDICATING THAT
INDEED METHANE WAS FLOWING.
WE FOUND A WORLD THAT WAS
REMARKABLY LIKE EARTH IN SO MANY
WAYS.
IN FACT, THERE WERE LAKES AND
SEA AT TITAN'S NORTH POLE.
IN FACT, THIS LAKE IS ABOUT 50%
LARGER THAN LAKE SUPERIOR.
IT'S ABOUT 500 FEET DEEP WHICH
IS ABOUT THE DEPTH OF THE GREAT
LAKES AS WELL.
SO THERE'S A TREMENDOUS VOLUME
OF METHANE ON THE SURFACE OF
TITAN.
AND IN FACT, IF YOU COULD GATHER
UP ALL OF THAT METHANE, YOU'D
HAVE TEN TIMES MORE HYDROCARBONS
THAN ALL OF THE RESERVOIRS WE
HAVE HERE ON THE EARTH.
SO IF ONLY WE COULD BUILD A
PIPELINE BIG ENOUGH FROM TITAN
BACK TO THE EARTH, OUR PROBLEMS
WOULD BE SOLVED BUT THERE'S A
TREMENDOUS AMOUNT OF HYDROCARBON
ON THE SURFACE.
YOU CAN SEE THE CHANNELS FLOWING
INTO THAT PARTICULAR SEA.
DUNES, THOSE PARTCALS THAT FORM
IN THE ATMOSPHERE, THEY FORM
DUNES THAT WRAP AROUND THE
TITAN.
SO THERE'S ALSO MOUNTAINS.
THIS IS A MOUNTAIN COLOR CODED
WITH HEIGHT.
MOUNTAINS CAN BE AS HIGH AS
KILOMETER OR SO.
WE THINK PERHAPS IN THIS CASE
YOU LOOK AT IT, IT MIGHT HAVE
BEEN AN ANCIENT VOLCANO FOR
WATER MIXED WITH AMMONIA.
AND THEN PERHAPS WITH THAT WATER
PERHAPS CAME THE METHANE.
THERE'S NOT ENOUGH METHANE IN
TITAN'S ATMOSPHERE TO HAVE
LASTED FROM THE TIME TITAN
FORMED.
SO THERE NEEDS TO BE SOME
INTERNAL SOURCE PERIODICALLY
RELEASING METHANE.
OTHERWISE, ONCE THE METHANE GETS
DIVIDED UP IN THE UPPER
ATMOSPHERE THE ATMOSPHERE WOULD
COLLAPSE.
SO THERE'S SOME SOURCE OF THAT
METHANE.
CLOUDS, WE HAVE SEEN LOTS OF
CLOUDS.
THIS IS A COLORIZED CLOUDS.
WE HAVE SEEN LOTS OF CLOUDS AND
WEATHER ON TITAN.
WE HAVE SEEN A METHANE RAINSTORM
ON TITAN THAT DARKENED THE
SURFACE AND THEN WE WATCHED FOR
A TIME AS THE SURFACE SLOWLY
DRIED UP.
THEN HERE'S THE VIEW OF THE DRY
RIVER BED.
NOW, IN LOOKING AT THESE IMAGES
WHAT YOU SEE HERE, THE LAKES AND
THE DUNES ARE TAKEN AT RADAR
WAVE LENGTHS.
RADAR WAVE LENGTHS ARE GOOD AT
PENETRATING THROUGH THE RAYS SO
WE HAVE SEEN A LARGE PORTION OF
THE SURFACE.
THIS VIEW IS WHAT YOU WOULD SEE
WITH THE CAMERAS.
YOU CAN SEE THE NORTH POLAR
REGION.
WE CARRIED NEAR INFRARED FILTERS
SPECIFICALLY DESIGNED TO GO
THROUGH AND PENETRATE THE HAZE
AND LOOK AT THOSE.
ONE OF THE THINGS IN THE
BEGINNING WE DIDN'T KNOW FOR
SURE IS IN THOSE LAKES WAS THAT
TRULY A LIQUID OR SOME KIND OF A
GOO OR SOMETHING?
WHAT WAS IT?
AND WE WERE TRYING TO FIGURE OUT
HOW DO WE FIND OUT IF IT'S A
LIQUID WITHOUT GOING THERE,
LANDING IN THE LAKE AND FINDING
OUT?
AND IT TURNS OUT WE HAVE ANOTHER
INSTRUMENT, INFRARED MAPPING
SPECTROMETER, LOOK AT THE
WAVELENGTHS AND AT FIVE MICRONS
IT FOUND A BROWN SPOT CALLED A
SPECK YOU LAR REFLECTION.
YOU HAVE A LIQUID SURFACE, IT
COMES OUT AT THE SAME ANGLE AND
CASSINI IS LOOKING AT THIS ANGLE
YOU WILL SEE A BRIGHT SPOT OVER
THE LAKE.
IF YOU HAVE EVER BEEN ON A AIR
PLAIN, IF YOU'RE LOOKING OUT THE
AFTERNOON WINDOW, YOU MIGHT
NOTICE THERE'S A BRIGHT SPOT
THAT POPS UP WHEN YOU GO OVER A
LIQUID.
THAT IS A REFLECTION.
I WANT TO SAY A LITTLE BIT ABOUT
THE RINGS, THEY HAVE SIMPLE
NAMES -- A THROUGH G.
WE KEEP NAMING THEM WITH OTHER
LETTERS AS MORE ARE DISCOVERED.
THE MAIN RINGS OF SATURN, OFF TO
YOUR LEFT.
THE MAIN RINGS YOU'D SEE THROUGH
THE TELESCOPE IS THE A-RINGS.
THE CASSINI DIVISION,
ASTRONOMERS FOR WHICH OUR
MISSION IS NAMED.
THE B-RING WHICH IS THE
OPTICALLY THICKEST RING.
THIS IS D RING IS VERY FAINT.
YOU HAVE THE TENUOUS, NARROW
F-RING OUTSIDE.
THEN HERE YOU HAVE THE E-RING
GOING ALL THE WAY OUT TO TITAN.
IT TURNS OUT THERE'S ONE MORE
RING IN THE SATURN SYSTEM.
THIS WASN'T DISCOVERED BY
CASSINI BUT IT WAS DISCOVERED BY
GROUND BASE OBSERVERS.
IT WAS CREATED BY PHOEBE, SO THE
PHOEBE RING THAT COMES INTO THE
SATURN SYSTEM AS WELL.
HERE'S A CASSINI VIEW OF THE
RINGS OF SATURN.
THEY'RE MADE MOSTLY OF WATER,
ICE, ON AVERAGE ONLY 30 FEET
THICK.
SO INCREDIBLY NARROW FOR THE
HUNDREDS OF THOUSANDS OF
KILOMETERS THAT THEY SPAN FROM
END TO END.
THERE'S TREMENDOUS AMOUNT OF
DETAILED STRUCTURE THERE.
SOME OF IT WE UNDERSTAND IS THE
INTERACTIONS WITH THE TINY MOONS
OUTSIDE, BUT SO MUCH OF THAT
STRUCTURE WE STILL HAVE NO IDEA
WHAT'S CAUSING THAT INCREDIBLE
STRUCTURE.
WE DO KNOW THAT THERE ARE TWO
MOONS THAT ACTUALLY OR IT THE
RINGS.
THERE'S ONE THAT ORBITS THE
YANKEE GAP AND THESE TWO MOONS
KEEP THEIR GAPS OPEN.
WE KNOW THAT INFORMATION ABOUT
THE RINGS AND HERE'S A NIGHT
VIEW OF THE DARK, VERY, VERY
TENUOUS D-RING.
THIS IS WHAT YOU WOULD SEE
THROUGH THE TELESCOPE.
THIS MOVIE TAKEN BY CASSINI
YOU'RE RIDING ALONG AS CASSINI
IS PLUNGING DOWN THROUGH THE
RING PLANES.
YOU CAN SEE THE A-RING, AND
B-RING AND THEN A TINY MOON WILL
GO BY.
THERE'S TITAN, MUCH LARGER.
NOW YOU GET TO SEE THE OTHER
SIDE, THE DARK SIDE OF THE
RINGS.
THE SIDE WHERE THE SUN ISN'T
SHINING.
AND IN THIS CASE THE B-RING
BLOCKS OUT THE SUNLIGHT.
THE CASSINI DIVISION IS VERY
BRIGHT.
YOU CAN SEE A HINT OF THE BRIGHT
C-RING.
SO THEY LOOK VERY DIFFERENT.
THAT'S THE ADVANTAGE IF YOU GO
TO THE PLACE LIKE SATURN, YOU
CAN SEE THE RINGS ON BOTH THEIR
LIT AND UNLIT SIDE.
NOW CASSINI ALSO HAD A RARE
OPPORTUNITY AT EQUINOX.
IN FACT, WE JUST HAD OUR AUTUMN
EQUINOX VERY EARLY THIS MORNING.
THAT'S WHEN THE SUN SHINES
DIRECTLY ON THE EQUATOR AND IN
THIS CASE IT SHINES ON THE RINGS
AT DAWN.
THAT'S IMPORTANT BECAUSE WITH
THE SUN EDGE ON TO THE RINGS YOU
HAVE ESSENTIALLY TURNED THE
SUNLIGHT OFF FOR THE RING AND
THIS MOSAIC TAKEN BY CASSINI
WHAT WE HAD TO HERE IS INCREASE
THE BRIGHTNESS BY A FACTOR OF
20.
THEY'RE ILLUMINATED AND ON THE
DARK SIDE OF THE RINGS WHERE
IT'S DARK BEFORE SATURN'S
SHADOW, YOU HAD INCREASED THE
CONTRAST BY A FACTOR OF 60.
YOU CAN SEE THE NARROW F-RING
BUT IT'S SLIGHTLY TILTED.
SO IT CAN STILL CATCH THE SUN
LIGHT EVEN AROUND EQUINOX.
A 30 FOOT RINGS YOU CAN LOOK FOR
ANYTHING THAT STINGS UP ABOVE OR
BELOW THE RING.
IF YOU'RE BIGGER THAN 30 FEET IN
SIZE THAT'S CHANCE YOU'LL CAST A
SHADOW AND WE CAN SEE YOU.
SO WE'RE LOOKING FOR OBJECTS
WITH CASSINI.
THAT WOULD BE LARGER AND WOULD
CAST SHADOWS.
SO I'M GOING TO SHOW YOU AN
IMAGE NOW.
THIS IS OUTER EDGE OF THIS RING,
THE B-RING.
IT'S STRETCHED.
LO AND BEHOLD, WE FOUND SHADOWS.
LOTS OF THEM.
TURNS OUT IT'S HELD IN PLACE BY
A RESONANCE WITH ONE OF SATURN'S
MOONS.
IT LOOKS LIKE SOME OF THE
LARGEST PARTICLES OR MAYBE THEY
FORM AND GROW RIGHT THERE AT THE
EDGE OF THE B-RING.
NOW, SOME OF THESE ARE PROBABLY
A KILOMETER OR TWO IN SIZE.
CASTING VERY LONG SHADOWS BUT
THERE ARE HUNDREDS OF THEM
ACROSS THE B-RING.
ALMOST LOOKING LIKE LITTLE
MOUNTAINS ALONG THE B-RING.
A GOOD ANALOGY IS IF YOU WANTED
TO SAY FIND THE PYRAMIDS, IF
YOU'RE LOOKING OUT FROM THE
SPACE STATION, IF YOU LOOKED
AROUND NOON THEY'D BE HARD TO
SEE AGAINST THEIR SANDY
BACKGROUND.
BUT, IF YOU LOOK NEAR DAWN OR
DUSK, THE EQUIVALENT OF EQUINOX
THEY'D MAKE THEM MUCH EASIER TO
SEE AGAINST THE SANDY
BACKGROUND.
WE FOUND DIFFERENT STRUCTURES
LIKE THIS THAT WOULD CAST
SHADOWS IN THE RING.
AS A SCIENTIST A VERY EXCITING
TIME TO BE LOOKING AT SATURN'S
RINGS.
FINALLY HERE'S A VERY
INTERESTING DISCOVERY FOR THE
RINGS.
IT TURNS OUT THAT THERE IS A
FEATURE, THIS FEATURE IS ABOUT
1200 KILOMETERS LONG.
TEN KILOMETERS OR SO WIDE.
INDICATING THAT THERE'S A TINY
OBJECT TWO OR THREE KILOMETERS
INSIDE, CREATING THIS FEATURE.
THIS FEATURE IS RIGHT AT THE
EDGE OF THE A-RING.
SO IT WAS DISCOVERED IN 2013.
IT'S DISCOVERED -- KARL MURRAY
DISCOVERED IT ON HIS MOTHER IN
LAW'S BIRTHDAY SO HE NICKNAME IT
PEGGY AFTER HER.
THIS TINY OBJECT HERE CREATING
THIS FEATURE, PEGGY WE HAVE BEEN
WATCHING FOR HER EVER SINCE.
SHE COMES AND GOES.
WE'RE WONDERING WILL SHE BREAK
FREE OF THE RINGS AND BECOME A
MOON IF HER OWN RIGHT OR BECOME
TORN APART AND JOSTLED BY THE
OTHER PARTICLES AND DISAPPEAR?
SO FAR SHE'S STILL THERE.
WE'LL KEEP WATCHING FOR HER
THROUGH THE END OF THE CASSINI
MISSION.
WE'VE BEEN ROOTING FOR HER FOR A
WHILE NOW.
SHE'S BEEN AROUND A FEW YEARS.
MOVING ON TO SATURN, ONE
INTERESTING EVENT HAPPENED AT
SATURN.
A GIANT STORM DEVELOPED TOWARD
THE END OF 2010.
THE STORM GREW SO HUGE IT WAS A
GIANT VORTEX AND THAT SWIRLED
OFF THIS HUGE TAIL.
THE TAIL OF THE STORM WRAPPED
ITSELF AROUND THE PLANET.
THERE WAS ANOTHER VORTEX ON THE
OTHER END, KIND OF LIKE A
HURRICANE.
WHEN THESE TWO VORTICES MERGED
THAT MARKED THE END OF THE
STORM.
A TREMENDOUS AMOUNT OF ENERGY
WAS RELEASED IN THIS STORM AT
SATURN.
TYPICALLY THE STORMS HAPPEN ONCE
EVERY 30 YEARS.
THIS WAS THE FIFTH TIME WE HAVE
SEEN A GIANT STORM LIKE THIS AT
SATURN.
BUT WHAT WAS UNIQUE, THIS STORM
WAS EARLY.
IT HAD BEEN ONLY 20 YEARS SINCE
THE LAST STORM SO IT CAME EARLY
SO CASSINI COULD GET A GOOD VIEW
OF IT AND WATCH IT, SO WE
WATCHED IT AS DID THE GROUND
OBSERVER WHICH LASTED NINE
MONTHS AND STARTED TO FADE.
THIS IS INVISIBLE IF YOU LOOK AT
THE RED, IT'S WHITE, OR YELLOW,
THAT'S HIGH UP IN THE
ATMOSPHERE.
GREEN IS ALSO HIGH UP.
THAT'S THE CENTER OF THE STORM.
AND THEN THE YELLOW -- ORANGES
AND THE REDS ARE LOOKING DEEPER
SO WE'RE BASICALLY GETTING A
PROFILE OF WHAT THAT STORM
LOOKED LIKE AND HOW THOSE CLOUDS
BEHAVED.
WE CAN MODEL THAT AND PERHAPS,
USE IT AS AN ANALOGY TO STORMS
IN THE EARTH'S ATMOSPHERE.
LOOKING AT THE LONGEST INFRARED
WAVELENGTHS, THERMAL, IT TURNS
OUT THAT THE STORM WAS IN THE
LOWEST ATMOSPHERE OF SATURN, BUT
WHEN THE TWO SPOTS MERGED IT
RELEASED A TREMENDOUS AMOUNT OF
ENERGY, LIKE A GIANT BURP.
HERE UP IN THE STRATOSPHERE IS A
VERY LARGE AND HOT FEATURE.
THIS PERSISTED FOR A COUPLE OF
YEARS AND SLOWLY COOLED.
VERY DYNAMIC AND ACTIVE SATURN,
AT LEAST IN THAT TIME PERIOD.
NOW, SATURN HAS A VERY
INTERESTING FEATURE AT THE NORTH
POLE.
HERE'S THAT FEATURE.
YOU'RE LOOKING DOWN AT THE NORTH
POLE OF SATURN.
THAT FEATURES THE SIX SIDED JET
STREAM CALLED THE HEXAGON.
IT WAS FIRST SEEN IN THE 1980s
AND IT WAS STILL HERE WHEN
CASSINI ARRIVED.
YOU CAN SEE THE PINKISH CLOUDS.
ROTATING AROUND, THEY GO FASTER
THE CLOSER YOU GET DIRECTLY TO
THE NORTH POLE.
AT THE NORTH POLE, THERE'S A
GIANT HURRICANE.
THIS HURRICANE IS ABOUT 50 TIMES
LARGER THAN A TYPICAL EARTH'S
HURRICANE GOING ABOUT 340 MILES
AN HOUR.
AND FINALLY, BEFORE I PASS IT
OVER TO EARL, THIS IS A VIEW OF
THE CHANGING SEASONS.
IN FACT, SATURN'S SHADOW ON THE
RINGS YOU CAN THINK OF AS A
GIANT SUN DIAL.
THIS PICTURE TAKEN BACK IN APRIL
OF 2016 YOU CAN SEE THAT THE
RING -- THE THAT DOE OF
SATURN -- THE SHADOW OF SATURN
GOES OUT PAST THE DIVISION.
AT SOLSTICE, THAT SHADOW WILL
PULL INTO THE MIDDLE OF THE
B-RING.
AS IT PULLS IN SO WILL CASSINI'S
TIME SHORTENED LIFE ON SATURN.
WITH THAT I TURN IT OVER TO EARL
TO TALK ABOUT THE GRAND FINALE.
>> SO HOW DOES CASSINI FOLLOW
THAT?
HOW DO I FOLLOW THAT?
I WANT TO GO FIRST NEXT TIME.
YOU KNOW, ONE OF THE THINGS
ABOUT CASSINI, IT ALWAYS TRUMPS
ITSELF.
AS WE KEEP FINDING -- ONE YEAR
WE ANNOUNCED THE SUB SURFACE
OCEAN.
NEXT YEAR A GLOBAL OCEAN.
SO IT KEEPS BUILDING AND
BUILDING AND BUILDING, THEN YOU
LOOK AMOUNT THE LAST -- LOOK AT
THE LAST 12 YEARS, HOW DO WE DO
SOMETHING MORE SPECTACULAR IN
THE FINAL YEAR?
WELL, I'M GOING TO SHOW YOU AT
LEAST THE POTENTIAL FOR THAT.
BUT BEFORE WE DO THAT, I WANT TO
DO A BIT OF A BACKUP HERE.
I WANT TO GO TO THE END.
THIS IS SEPTEMBER 14th, 2017.
IT'S ABOUT OH 2:00 IN THE
AFTERNOON HERE IN PASADENA.
CASSINI HAS JUST WRAPPED UP A 30
HOUR OR SO OBSERVING SESSION.
THE RECORDERS ARE PACKED FULL OF
IMAGES AND -- SO NOW IT'S TIME
FOR CASSINI TO TURN BACK TO
EARTH AND BEGIN TO PLAY THOSE
BACK.
SO THIS IS A HIGH SPEED, SLOW
SPEED VERSION OF THE LAST -- OF
THESE PERIODS.
SO CASSINI IS WORKING ON THIS
FOR TEN HOURS.
DSN IS RECEIVING ALL THE DATA.
WE'RE STREAMING THESE BACK AND
AS SOON AS WE SEE THEM, YOU'LL
SEE THEM.
SOME SPECTACULAR IMAGES OF THE
POLES AND OF THE RINGS AS WE
COME IN.
THEN WHEN THE SSRs, THE SOLID
STATE RECORDERS ARE EMPTY, IT
WILL BE ABOUT TEN HOURS.
CASSINI IS GOING TO RECONFIGURE
HERE AT SATURN.
WE HAVE DONE THAT 292 TIMES.
PERIAPSIS AT SATURN IS PRETTY
ROUTINE, BUT NOT THIS ONE.
THIS ONE IS ABSOLUTELY UNIQUE.
BECAUSE IT'S CASSINI'S LAST.
THREE DAYS BEFORE THIS EVENT,
CASSINI HAD A CLOSE ENCOUNTER
WITH TITAN.
TITAN GAVE A LITTLE
GRAVITATIONAL NUDGE AND THAT
NUDGE HAS PRETTY MUCH SEALED
CASSINI'S FATE.
AS A MATTER OF FACT, IT'S NOT
COMING OUT OF THIS PERIAPSIS.
IT'S MOVED THE PERIAPSIS THE
CLOSEST APPROACH DISTANCE INSIDE
THE CAPTURE RADIUS OF THE
SATURN'S ATMOSPHERE.
SO CASSINI IN THIS ONE IS GOING
TO RECONFIGURE ITSELF SO IT
DOESN'T PUT THE DATA ON THE
RECORDERS BUT EVERYTHING OUT ON
THE PIPE AS QUICK AS IT CAN.
IT'S GOING TO START TO TURN
COLORS HERE, AS SOON AS ITS
RECONFIGURES.
CASSINI WILL GO INTO THE
ATMOSPHERE AND EVERY SECOND IS
COMING BACK TO THE EARTH.
UNFORTUNATELY, CASSINI IS GOING
TO BE GOING 77,000 MILES PER
HOUR.
YOU CAN GET AROUND THE EARTH IN
ABOUT 20 MINUTES AT THAT SPEED.
SO WHAT'S GOING TO HAPPEN, IT'S
GOING TO HAPPEN VERY, VERY FAST.
WE ARE GOING TO HAVE THE --
EVERY PIECE OF DATA STREAMING
BACK DOWN.
WE'LL BE SAMPLING THE ATMOSPHERE
AND TRY TO ANSWER THE
FUNDAMENTAL QUESTIONS ABOUT
CASSINI, SATURN'S ATMOSPHERE.
BUT IT'S NOT VERY LONG.
AT 77,000 MILES PER HOUR,
CASSINI GOING IN WITH ITS
ANTENNA POINTING TO THE EARTH.
BUT THE MATCH -- ATMOSPHERE IS
GOING TO QUICKLY OVERPOWER ITS
ABILITY TO POINT.
IT DOESN'T HAVE THAT KIND OF
CONTROL.
IT'S GOING TO PUSH IT OFF.
AND THEN WE'LL LOSE -- IT WILL
ESSENTIALLY DISAPPEAR FROM OUR
MONITORS AND ABOUT THREE OR FOUR
MINUTES LATER THAT SPEED AND THE
DENSITY OF SATURN'S ATMOSPHERE
WILL VAPORIZE CASSINI AN IT IS
OVER.
ONE OF THE MOST SPECTACULAR
MISSIONS EVER TO LEAVE EARTH, A
DISCOVERY MACHINE LIKE YOU WILL
NEVER SEE AND IT'S GOING TO BE
DONE.
SO WHY ARE YOU DOING THAT?
LIKE DID YOU GUYS ASK ANYBODY'S
PERMISSION TO TAKE SOMETHING
THAT IS REWRITTEN, SCIENCE
PROGRAMS, REDIRECTED NASA
PROGRAMS AND RECON TORE THE
MISSIONS YOU'RE GOING TO DESTROY
IT?
TRY TO EXPLAIN WHY WE THINK
THAT'S A GOOD IDEA.
IN ORDER TO DO THAT I HAVE TO GO
BACK A LITTLE WAYS.
SO BACK TO 2009.
LINDA TOLD YOU ABOUT THE PRIME
MISSION AND THE EXTENDED
MISSIONS.
WE GOT TO SATURN 2004.
RIGHT, WE HAD A FOUR-YEAR
MISSION.
BUT WE DIDN'T HAVE ANY END.
THERE WAS NO END GAME PLANNED.
BUT WE GOT TO THE END OF THAT
MISSION.
REALIZED WE HAD AN INCREDIBLY
GOOD SPACECRAFT.
WE WENT FOR ANOTHER TWO YEARS.
ABOUT MIDWAY THROUGH THAT SECOND
MISSION, 2009, GEE, ALL
SUBSYSTEMS ARE GREAT, THIS
SYSTEM IS WONDERFUL, WE HAVE A
LOT OF GAS IN THE TANK LET'S DO
SOMETHING ELSE.
SO WHAT?
WHAT'S NEXT?
AND WE ACTUALLY GOT A LOT OF
STUDIES DONE.
YOU KNOW, THERE'S A LOT OF
OPPORTUNITIES AT THIS POINT WITH
ALL OF THE -- WE COULD HAVE LEFT
SATURN.
WE COULD HAVE GONE OFF TO THE
CENTAUR ASTEROIDS.
AND WE COULD HAVE REPURPOSED
CASSINI AS THE ASTEROID MISSION
OR GONE OUT TO URANUS OR OUT TO
NEPTUNE.
NOW I HAVE TO SAY, THIS WAS A
40-YEAR CRUISE, SO YOU KNOW, I
MEAN, IT WOULD HAVE BEEN A LONG
CRUISE.
BUT LOOK AT WHERE THE VOYAGER
IS.
IT WAS POSSIBLE.
WE COULD HAVE GONE BACK TO
JUPITER.
THAT ACTUALLY IS AN IMAGE WE
TOOK ON THE WAY OUT.
WE COULD HAVE GONE BACK.
YOU KNOW, THE SAME SET OF
RESOURCES ON JUPITER.
URANUS IS A POSSIBILITY.
OR MORE SATURN.
WELL, YOU KNOW, THIS IS KIND OF
A NO-BRAINER.
I MEAN, WE HAD BARELY SCRATCHED
SURFACE.
SATURN IS JUST INCREDIBLE.
YOU COULDN'T ASK FOR A MORE
DYNAMIC ENVIRONMENT.
YOU'VE GOT THE RINGS, GOT THE
PLANET, GOT THE ICY SATELLITES.
YOU HAVE TITAN AND ENCELADUS
LITTLE PREBIOTIC WORLDS ON THEIR
OWN.
OKAY, WE HAVE TO STAY.
SO I'LL JUMP TO THE CHASE REAL
QUICK.
NO, WE'RE NOT GOING THERE.
NO WE'RE NOT GOING THERE.
WE'RE GOING TO STAY.
BUT THERE'S A CATCH.
IF YOU WANT TO STAY AT SATURN,
THERE'S SOME RULES AND THEY
ARE -- WE CALL IT PLANETARY
PROTECTION BUT THE REAL ESSENCE
OF THIS IS YOU'VE GOT TO PROTECT
SATURN.
MY APOLOGIES TO THE OAK RIDGE
BOYS, BUT YOU CAN VISIT, BUT YOU
CAN'T STAY.
SO YOU HAVE GOT TO MAKE SURE
THAT IF YOU STAY IN SATURN'S
SYSTEM THERE'S NO POSSIBILITY OF
A CRASH LANDING ON ENCELADUS OR
TITAN.
CASSINI IS ROOM TEMPERATURE
INSIDE.
IF THERE ARE LITTLE MICROBES IN
THERE THAT DON'T MIND THE VACUUM
THEY CAN JUST LAST FOREVER.
WE'RE RUNNING ESSENTIALLY AT 72
DEGREES INSIDE THE SPACECRAFT.
SO GOING AND TAKING SOME OF OUR
EARTH MICROBES OR SPORES ON THE
ENCELADUS IN PARTICULAR WHERE WE
KNOW THERE'S WATER, WARM WATER,
WOULD BE ABSOLUTELY
UNACCEPTABLE.
SO YOU GUYS CAN STAY, BUT YOU'VE
GOT TO BE CAREFUL ABOUT WHAT YOU
DO ABOUT TITAN AND ENCELADUS.
SO WITH THAT IN MIND, HOW ARE WE
GOING TO DO THAT?
WE COULD STAY AND DO BIG LONG
ORBITS.
STAY WAY OUTSIDE THE ORBITS OF
ENCELADUS, STAY OUTSIDE OF
TITAN, BUT GUESS WHERE ALL THE
SCIENCE IS?
WE WANTED TO EXPLORE THE GUYS
BUT WE WARRANTED TO REMAIN -- WE
WANTED TO REMAIN SAFE.
WE HAVE A BIT OF PROPELLANT,
WHAT CAN YOU DO FOR US?
WE WANT TO STAY INSIDE SATURN'S
SYSTEM, WE WANT TO EXPLORE ALL
THE ICY SATELLITES BUT WE WANT
TO REMAIN SAFE FOR THESE TWO,
YOU KNOW, INCREDIBLE WORLDS.
SO WHAT THESE GUYS GAVE US WAS
THE SOLSTICE MISSION TRAJECTORY.
THIS STARTED IN 2010.
AND THIS IS A TRAJECTORY
DESIGNER'S MASTERPIECE.
A LOT OF SQUIGGLY LINES BUT EACH
OF THOSE IS AN ORBIT.
EVERY TEAM THAT ORBIT CHANGES
SHAPE IT'S BECAUSE TITAN MOVED
US.
SO AS LINDA SAID WE GET A
VELOCITY CHANGE EVERY TIME WE
FLY BY TITAN.
SO YOU WANT TO GO UP, IT PULLS
YOU UP.
YOU WANT TO GO IN, GO TO THE
RIGHT AND THE LEFT.
AND WE TAKE YOU ALL OVER THE
SYSTEM.
WE TOOK THE ORBITS, STAYED
FLAT -- THAT'S SATURN IN THE
MIDDLE.
VERY FLAT AND THEN YOU COULD DAY
AND DO ALL OF THE SATELLITE
INTERROGATION YOU WANT.
YOU CAN DO VERY INCLINED.
VERY LOOPING ORBITS, DO MAGNETIC
FIELDS.
DO THE POLES AND THE RINGS AND
AS A BONUS TO ALL OF THAT, THIS
IS THE FIRST SIX YEARS OF THE
MISSION.
THE MISSION THAT LINDA JUST
REPORTED.
YOU ALSO GET THIS.
THIS IS THE LAST YEAR OF THE
MISSION.
AND THIS IS UNFORTUNATELY AT THE
END THE DEMISE OF CASSINI AS I
JUST DESCRIBED A FEW MOMENTS
AGO.
BUT ON THE WAY IN, WE HAVE AN
ENTIRELY NEW MISSION.
SOMETHING WE HAVE NEVER DONE
BEFORE.
WE'LL FLIRT WITH THE OUTSIDES OF
THE RINGS AND GO DIVING DEEP
INSIDE THE RINGS.
I'LL SHOW YOU A LITTLE BUILD
MORE ABOUT, JUST TO SHOW OFF
SOME.
THESE THINGS ARE PHENOMENAL.
THE KEY ORBITAL CHARACTERISTICS,
WHAT QUESTION CALL THE F-RINGS
AND THE PROXIMALS.
YOU WILL HEAR THEM CALLED
PERPOE.
SOUNDS LIKE A DOG FOOD MORE THAN
THE ACRONYM.
BUT 42 SHORT PERIOD ORBITS EACH
OF THESE ORBITS LASTS A WEEK.
20 OF THEM ARE GOING TO BE --
OOPS, I HIT THE WRONG BUTTON.
SORRY.
HIT IT AGAIN.
THERE WE GO.
20 OF THEM ARE GOING TO BE JUST
OUTSIDE THE F-RING.
RIGHT, THIS IS THE OUTER MOST
RING HERE.
TITAN IS GOING TO BE -- BOTH OF
THESE ARE ESSENTIALLY RUNNING
THE TITAN OUT HERE.
20 OF THESE OUTSIDE WITH GREAT
COVERAGE OF THE POLES AND THE
RINGS AND THEN ANOTHER TITAN FLY
BY IS GOING TO MOVE US IN TO THE
GAP BETWEEN THE INNER MOST
D-RING AND THE OUTER MOST EDGES
OF THE ATMOSPHERE.
22 OF THOSE.
THE PERIAPSIS IS GOING TO BE THE
2400 KILOMETER CLEAR ZONE
BETWEEN THEM.
ESSENTIALLY -- WE'VE GOT THEIR
DUST ON THE LEFT AND WE'VE GOT
THE SATURN ON THE RIGHT.
WE HAVE TO NAVIGATE IN BETWEEN.
NEXT SLIDE IS I THINK A LOOK AT
THE VIEW FROM EARTH.
NOT ONLY ARE THESE THINGS
PHENOMENAL FROM THE PROXIMITY,
BUT THE GEOMETRY IS PHENOMENAL.
BECAUSE IF YOU LOOK AT WHAT
HAPPENS HERE, THESE ORBITS GO
BEHIND THE RINGS AND BEHIND
SATURN.
ALMOST EVERY ONE OF THEM A VIEW
FROM EARTHS PROVIDES OK
CULLATION.
NOT ONLY DO WE HAVE INSTRUMENTS
THAT CAN PHOTOGRAPH AND SAMPLE,
BUT WE HAVE INSTRUMENTS THAT CAN
SEND A TUNED RADIO SIGNAL TO
EARTH.
AND PASSING THAT SIGNAL THROUGH
THE RINGS AND THE ATMOSPHERE CAN
TELL US A TREMENDOUS AMOUNT
ABOUT THEIR INTERNAL STRUCTURE.
THE OPPORTUNITIES HERE ARE
ABSOLUTELY PHENOMENAL.
BY THE WAY, SATURN HAS
OBLIGED -- IF YOU RECALL BACK TO
LINDA'S PICTURE NEVER OPENING UP
THE RINGS MORE THAN THEY ARE
RIGHT NOW.
SO ESSENTIALLY PASSING RIGHT
THROUGH, IT'S AN ABSOLUTELY
UNIQUE AND SPECTACULAR
OPPORTUNITY.
THIS AGAIN IS JUST TO SHOW A
LITTLE BIT OF WHAT HAPPENS AT
THE PERIAPSIS.
YOU CAN SEE -- YOU DON'T QUITE
SEE THE F-RING ON THIS
ILLUSTRATION.
BUT IT IS RIGHT -- AS I BEGIN.
THERE WE GO.
WE HAVE A -- THESE RINGS HERE,
THE F-RING IS COMING OUT RIGHT
HERE.
WE HAVE ABOUT AN 8,000 KILOMETER
GAP THERE.
BUT THERE'S EXTENDED DUST AND IF
YOU LOOK AT THE F-RING I'M MORE
TERRIFIED ABOUT THAT THAN ABOUT
THE GAP.
BECAUSE OF THE TENDRILS THAT
KEEP COMING OFF THE F-RING.
NEVERTHELESS, THAT'S WHERE WE'RE
GOING.
THEN AGAIN, WE SEE THE PROXIMITY
OF THESE PERIAPSIS HERE INSIDE
THE -- WHAT WE CALL THE
PROXIMALS.
THE GRAND FINALE.
THIS IS AGAIN JUST KIND OF
SHOWING OFF, BUT HERE IS A
FLATTENED OUT VERSION.
THESE ARE THE RINGS OF SATURN.
HERE'S THE F-RING UP HERE.
HERE IS SATURN'S ATMOSPHERE DOWN
HERE.
SATURN'S ATMOSPHERE.
SATURN DOESN'T HAVE A SURFACE OR
IF IT DOES IT'S WAY DOWN IN
THERE.
SO WHAT WE CALL THE SURFACE IS
ESSENTIALLY ONE BAR LEVEL.
ESSENTIALLY THE PRESSURE SEA
LEVEL.
THAT'S WHAT WE'RE CALLING THE
SURFACE OF SATURN.
HERE ARE GRAPHICALLY EACH OF THE
PERIAPSIS.
SO WE'RE FLIRTING AROUND IN THE
SAFE LITTLE GAP BETWEEN THE
F-RING --
WE'LL GET TO THAT.
BETWEEN THE -- THE RINGS HERE,
INCREDIBLY PRECISE NAVIGATION TO
STAY BETWEEN THE DUST HAZARDS
AND THE TITAN FLY BY THAT BRINGS
US DOWN IN HERE.
THEN WE STAY VERY CAREFULLY AND
VERY PRECISELY WITHIN THE GAP
BETWEEN SATURN'S ATMOSPHERE AND
THE DUST UNTIL OUR FINAL FLY BY
HERE.
I SHOULD POINT OUT THERE ARE A
COUPLE THAT WERE FLIRTING WITH
THIS.
WE'LL DO SOME THINGS TO KEEP
OURSELVES SAFE.
THEY'RE MORE DICEY THAN THE
OTHERS.
OKAY, SO WHAT'S IT LIKE TO BE ON
CASSINI WHEN DOING THIS?
I ALWAYS -- I HAVE STOLEN MY
THUNDER ON THIS SLIDE A COUPLE
OF TIMES.
IMAGINE YOU'RE SITTING ON THE
PROUD CASSINI GOING THROUGH.
THIS IS SEVEN SECONDS OF TERROR
EVERY SEVEN DAYS FOR SEVEN PLUS
TWO MONTHS.
SO MARS HAS GOT THEIR SEVEN
MINUTES.
WE HAVE SEVEN SECONDS EVERY
SEVEN WEEKS.
WE WON'T KNOW, BECAUSE MOST OF
THE TIME GOING THROUGH HERE WE
DON'T WANT TO HAVE THE
SPACECRAFT TALKING US TO.
WE WANT IT TO BE DOING SCIENCE.
SO WE'LL FIND OUT IF WE SURVIVED
THE RING PLANE CROSSINGS LATER
IN GAME.
BUT THAT'S THE WAY IT GOES.
YOU WANT TO GET THE SCIENCE.
SO THIS IS GOING TO HAPPEN 22
TIMES.
EVERY TUESDAY I BELIEVE.
BUT I COULD BE WRONG ABOUT THAT.
SO MY FLIGHT TEAM, WE ARE GOING
TO BE VERY, VERY BUSY.
SO THE SCIENCE.
I LOVE THE ENGINEERING OF ALL OF
THIS, BUT REALLY THE ENGINEERING
IS ALL IN IT BECAUSE OF THE
SCIENCE.
THIS IS -- THIS IS JUST SOME OF
THE UNIQUE THINGS.
YOU HAVE SEEN WHAT LINDA SHOWED
ALREADY AND IT IS PHENOMENAL.
WE'LL CONTINUE TO DO SOME MORE
OF THAT EVEN WHILE WE'RE HERE.
BUT THESE ARE THE OPPORTUNITIES
THAT WE'LL NEVER EVER GET ANY
OTHER TIME.
SATURN INTERNAL STRUCTURE AND
MAGNETIC FIELD AND GRAVITY.
WE CAN FLY IN BETWEEN THE RINGS
WE CAN GET A SENSE OF WHICH ONE
IS WHICH.
THAT TELLS US SOMETHING VERY
FUNDAMENTAL.
BELIEVE IT OR NOT, WE DON'T KNOW
HOW WOULD THE RINGS WITH.
THEY COULD BE A COUPLE HUNDRED
YEARS, A BILLION YEARS.
THERE'S A BIG ARGUMENT ABOUT
THAT AND VERY INTELLIGENT PEOPLE
ON BOTH SIDES OF THE CASE.
WE THINK WE CAN HELP WITH THE
MEASUREMENTS.
SATURN'S ATMOSPHERE AND THE
INNER MOST RING PARTICLES AND
THE HIGHEST RESOLUTION RING
ITSELF.
WHEN WE WENT INTO ORBIT IN 2004
WE WENT OVER THE RINGS.
BUT THEY WERE NOT LIT.
WE GOT THE DARK SIDE.
SO NOW WE CAN FINALLY SEE THESE
RINGS FULLY ILLUMINATED BY THE
SUN.
AS I SHOWED THAT PICTURE
EARLIER, SATURN'S COOPERATING BY
PROVIDING A GOOD PHASE ANGLE OF
THE SUN.
ALSO RADAR OF THE RINGS.
YOU SAW THE RADAR IMAGES OF
TITAN.
POLAR OBSERVATION AND AURORA
SATURN AND THEN AS I MENTIONED
IN THE FIRST SLIDE, WE ARE
ACTUALLY GOING TO SAMPLE SAT YOU
WERE'S ATMOSPHERE.
EVERY OUNCE OF CASSINI'S LAST
EFFORT WILL BE MADE IN TRYING TO
UNDERSTAND AND ANSWER SOME OF
THE FUNDAMENTAL QUESTIONS ABOUT
THE HYDROGEN AND HELIUM RATIOS
AND THINGS LIKE THAT.
SO WE'LL SEE.
LET ME QUICKLY RUN THROUGH THIS.
NOVEMBER 30th, RIGHT AFTER
THANKSGIVING, THIS WHOLE THING
STARTS AND THIS IS JUST TO SHOW
YOU NOT ONLY -- SOMETIMES YOU
GET YOUR GOOD, SOMETIMES YOU'RE
LUCKY.
THE LONGITUDINAL COVERAGE OF THE
F-RINGS IS PHENOMENAL.
WE'LL GET THE WHOLE PLANET
COVERED WITH THE EFFORTING TIME
LINE.
20 ORBITS.
APRIL 22nd IS OUR FIRST TARGETED
FLY BY.
THE LAST TARGETED FLY BY.
THIS IS THE ONE FROM TITAN THAT
WILL PUSH US IN.
HERE'S THE F-RING.
FINAL F-RING ORBIT.
WE'LL COME AROUND AND THEN HERE
COMES TITAN.
WATCH WHAT HAPPENS TO THIS
ORBIT.
BOOM.
IT'S ABOUT A COUPLE THOUSAND
KILOMETERS SO IT'S PRETTY CLOSE.
BUT NOW RATHER THAN GO OUTSIDE,
IN WE GO.
THAT'S GOING TO HAPPEN FOR 22
TIMES.
AND SO THERE'S THAT AND I WILL
SHOW YOU 22 MORE.
APRIL 23rd, GRAND FINALE BEGINS.
WE HAVE A LOT OF TITAN FLY BYES
PUSHING US AROUND.
I WON'T SHOW YOU A WHOLE LOT OF
THOSE.
BUT THE FIRST I HAVE SEEN THE
GAP -- HERE'S THE LONGITUDE --
IT'S A PERFECT GRID ALMOST ALL
THE WAY AROUND THE PLANET.
PHENOMENAL.
THE FIRST GAP SON APRIL 26th.
THEN SEPTEMBER 11th OUR LAST FLY
BY OF TITAN.
WE CALL IT T-292.
IT'S A DISTANT FLY BY, ABOUT
100,000 KILOMETERS, BUT IT
DOESN'T TAKE US MUCH TO PUSH US
INTO THE IMPACTING TRAJECTORY.
SEPTEMBER 15th, BOOM, WE'RE IN.
THE END OF THE MISSION, AND THE
END OF A VERY SPECTACULAR SET OF
INVESTIGATIONS TO SATURN.
SO I WANT TO SHARE A CARTOON
WITH YOU THAT WE AT THE FLY TEAM
LIKE TO PASS AROUND.
HEY CASSINI I HEAR YOU'RE
RETIRING.
HOW ABOUT THAT?
CONGRATS.
DO YOU WANT TO CELEBRATE?
MAYBE LUNCH WITH ME AND MY
MOONS.
HOW ABOUT THAT?
NO, I'M GOING BARRELLING
STRAIGHT INTO YOUR ATMOSPHERE.
LEARNING AS MUCH AS I CAN BEFORE
I'M CRUSHED TO DEATH AND
VAPORIZED TO SPECTACULAR
SWIRLING INFERNO BENEATH YOUR
STEAMY CLOUDS.
YOU CAN IMAGINE SATURN'S
REACTION TO THAT.
THE SAME -- THE SAME ONE THAT WE
ALL HAVE.
MAYBE YOU ALL HAVE WHEN YOU SEE
WE'RE GOING TO BURN THIS THING
UP.
YOU THINK ABOUT THAT FOR A
LITTLE BIT.
HOPEFULLY WHAT I HAVE JUST TOLD
YOU YOU MIGHT COME TO AGREE WITH
ALL OF US THAT IT'S TOO BAD,
IT'S A WONDERFUL MACHINE.
IT'S BEEN AN INCREDIBLE
DISCOVERY, BUT IT'S AWESOME.
>> OKAY.
WE'D BE HAPPY TO ENTERTAIN ANY
QUESTIONS YOU MIGHT HAVE.
AND IF YOU DO HAVE A QUESTION,
WE APPRECIATE YOU GOING UP TO
THE MICROPHONE.
>> THANK YOU FOR REALLY AWESOME
PRESENTATIONS.
SO I BELIEVE THAT THE JUNO
MISSION IS USING HIGHLY
ELLIPTICAL ORBITS TO EXPLORE THE
INTERNAL STRUCTURE OF JUPITER.
YOU SAID YOU'RE PROBING THE
MAGNETIC AND GRAVITATIONAL
FIELDS OF SATURN.
SO MY QUESTION IS, JUPITER THEY
EXPECT TO CONFIRM THE EXISTENCE
OF METALLIC HYDROGEN.
DOES SATURN HAVE ENOUGH
GRAVITATIONAL PRESSURE TO FORM
METALLIC HYDROGEN, DO YOU
BELIEVE?
>> YES, SATURN HAS ENOUGH
PRESSURE INSIDE TO FORM
HYDROGEN.
WE'RE WONDERING IF WE CAN
DEDETECTIVE THAT INSIDE SATURN.
CASSINI IS ONLY TIPPED AT 63
DEGREES AND THAT'S BASICALLY OUR
OPTIMUM ORBITS FROM THE
PERIAPSIS PUTTING US PREMATURELY
INTO THE RINGS.
VERY COMPLIMENTARY SCIENCE
PROBING THE TWO GAS GIANTS AND
THEN COMPARING THE RESULTS.
>> THANK YOU.
>> THANK YOU FOR THE GREAT
PRESENTATION.
I WANTED TO ASK ABOUT
CONTINGENCIES DURING THIS FINAL
YEAR.
YOU'RE ON A RISKY PATHWAY AND IF
SOMETHING WERE TO HAPPEN TO THE
SPACECRAFT ON ONE OF THESE
PASSES THROUGH THE RINGS, WHAT
DO YOU EXPECT TO BECOME OF THE
REST OF THE MISSION?
IS THERE A CHANCE THAT IT CAN
STILL HAVE ITS CRASH INTO SATURN
OR WHAT?
>> YEAH.
ONE OF THE THINGS THAT'S PRETTY
AMAZING ABOUT THIS TRAJECTORY IS
ONCE WE HAVE FLOWN BY THE FINAL
TITAN FLY BY IF WE LOSE THE
SPACECRAFT IT'S STILL GOING IN.
IT'S -- AND AS A MATTER OF FACT,
AFTER T-125 WE REQUIRED THE
ULTIMATE FLY BY.
AND MINIMUM TRAJECTORY
MAINTENANCE.
WE'RE ESSENTIALLY ON A BALLISTIC
TRAJECTORY TO THE ENTRY.
THAT BEING SAID, IF THERE ARE --
IF THERE ARE WORK CONTINGENCIES
IN CASE WE FIND THE DUST IS
HIGHER THAN WE WANT, WE CAN HIDE
BEHIND THE ANTENNA.
IF THE ATMOSPHERE IS THICKER
THAN WE'D LIKE, ALTHOUGH SOME OF
THE SCIENCE THINK THAT'S JUST
GREAT WE CAN MOVE OURSELVES OUT
A LITTLE BIT.
SO WE'RE MAKING SURE THAT THE
MISSION IS AS SUCCESSFUL AS
POSSIBLE.
BUT IF WE'RE DAMAGED WE'RE
STILL -- WE CAN KEEP THE PROMISE
TO ENCELADUS.
>> AND IF THE ATMOSPHERE SHRINKS
THAT'S A POSSIBILITY.
WE HAVE A PLAN TO GO LOWER
BECAUSE WE WANT TO DIP OUR TOE
FOR SURE IN THAT ATMOSPHERE.
>> HI.
THIS IS MORE OF A QUESTION ABOUT
THE CAPABILITY OF THE
SPACECRAFT.
SO I UNDERSTAND THAT THE
DECISION TO DEORBIT IS QUITE
FINAL, BUT WOULD IT EVER HAVE
BEEN POSSIBLE TO ATTEMPT -- YOU
KNOW, IS THERE SUFFICIENT DELTA
"V" IN THE TANKS TO ATTEMPT A
SMALLER MOON LANDING?
YOU KNOW, USE THE LOW GAIN
ANTENNA, SEND ANOTHER SPACECRAFT
LATER AND HAVING A PASSIVE
ORBIT --
>> I'M AFRAID -- WELL, THAT
COULD HAVE BEEN IN THAT SET OF
SCENARIOS.
THERE MAY HAVE BEEN A LANDING
SCENARIO THAT WE DIDN'T WORK.
BUT NOW THERE'S ABSOLUTELY NOT.
WHEN WE DESIGNED THE SOLSTICE
MISSION, WE DESIGNED -- YOU
DON'T WANT TO END THE MISSION
WITH A FULL TANK.
IN FACT, YOU WANT TO END WIT A
COMPLETELY EMPTY TANK AND RIGHT
NOW WE'RE ALMOST COMPLETELY
EMPTY.
SO THE POSSIBILITY OF A
CONTROLLED LANDING ON ANYTHING
WOULD BE ABSOLUTELY OUT OF THE
QUESTION.
AGAIN, THOSE CERTAIN THINGS --
MOST OF THE CONTROLLED LANDINGS
THAT WE SEE ARE REALLY MORE LIKE
CONTROLLED CRASHES.
LOW SPEED CRASHES SO REALLY THE
REALISTIC OPPORTUNITY TO CREATE
A BEACON I THINK YOU WANT TO
DESIGN SOMETHING LIKE HUYGENS.
THAT ACTUALLY IS BUILT TO
BROADCAST SOMETHING AND
UNFORTUNATELY IT WAS ON
BATTERIES.
THAT WAS THAT.
BUT NOW IT'S LIKE I SAID, THE
DECISION IS MADE.
WE HAVE SPENT ALL OF OUR
PROPELLANT DOING WHAT WE HAVE
BEEN DOING.
THANKS FOR THE QUESTION.
>> THANK YOU BOTH FOR THAT
PRESENTATION.
IT WAS EXCELLENT.
YOU NOTED EARLIER YOU'RE
CONCERNED OVER CONTAMINATING THE
ENVIRONMENTS OF ENCELADUS AND
TITAN.
HOW WERE YOU ABLE TO PREVENT
THAT WHEN YOU LANDED HUYGENS
PROBE ON THE SURFACE OF TITAN?
>> OH, GOOD QUESTION.
I THINK THE KEY DIFFERENCE
BETWEEN THOSE IS THAT CASSINI IS
POWERED BY THESE RADIO ISOTOPES
WITH PLUTONIUM ON BOARD.
TO ACCESS THE OCEAN ON ENCELADUS
YOU'D PROBABLY HAVE TO MELT
THROUGH SOME ICE AND WITH THE
HEAT FROM THAT PLUTONIUM THAT
MIGHT BE A POSSIBILITY.
HUYGENS PROBE HAD BATTERIES AND
HAD SOME SMALL RHU HEATERS.
WHEN WE LANDED ON TITAN WE
DIDN'T KNOW ABOUT THE METHANE
LAKE AND THAT TITAN HAD A GLOBAL
OCEAN AND WE DIDN'T KNOW ABOUT
ENCELADUS.
SO A LOT OF THINGS LIKE EARL
SAID IT'S LIKE A VICTIM OF HER
OWN DISCOVERY.
>> THANK YOU.
>> ABSOLUTELY SUPERB
PRESENTATIONS OF COURSE.
QUICK QUESTION, WHAT'S THE CAUSE
OF THE HIGHLIGHTS THAT WE SEE
HERE AT 12:00 AND 6:00 ON THE
OUTER MOST RINGS?
>> EXCELLENT QUESTION.
WHAT IS THE CAUSE OF THE BRIGHT
SPOTS?
IT TURNS OUT THAT THOSE SPOTS
ARE ACTUALLY -- IF YOU PULLED IN
CLOSER TO THE SUN SO IT'S PHASE
ANGLE EFFECT.
IF YOU CAN THINK IT OF THAT WAY.
THE ANSAH ARE FURTHER AWAY FROM
THE SUN THAN AT THE POINTS OF
THE NORTH AND THE SOUTH.
AS MANY THINGS BRIGHTEN AS YOU
GET TO THE DISTANCE BETWEEN THE
SUN AROUND YOUR TARGET.
GOOD QUESTION THOUGH.
GOOD CATCH.
>> THANK YOU FOR A WONDERFUL
PRESENTATION, I REALLY ENJOYED
IT.
KNOWING WHAT WE KNOW NOW ABOUT
SATURN, WHAT'S NEXT AND WHEN DO
WE GET TO GO?
>> WELL, THERE'S A PROPOSAL
CYCLE UNDER WAY NOW AND THAT'S A
FIXED LIST OF MISSIONS FOR NEW
FRONTIERS.
ONE OF THOSE IS THE SATURN
PROBE.
ONCE WE HAD A PROBE IN THE
GALILEO ATMOSPHERE, WE WANT TO
SEND IT INTO THE ATMOSPHERE.
WE WANT TO MEASURE THE GASES,
THERE ARE A HOST OF OTHER THINGS
YOU CAN DO WITH THE PROBE.
THERE WERE TWO TARGETS ADDED TO
THE LIST FOR NEW FRONTIERS.
THOSE ARE ENCELADUS AND TITAN.
BASICALLY THE WORLDS UNVEILED
LIKE CASSINI.
SO THERE ARE MISSIONS TO FLY
THROUGH THE PLUMES OF ENCELADUS
TO PERHAPS LOOK FOR THE AMINO
AND FATTY ACIDS.
MAKE MEASUREMENTS THERE, SO
THERE'S A WHOLE HOST OF
PROPOSALS.
30 OR 40, WHO KNOWS HOW MANY
NASA WILL GET SOME TIME NEXT
SPRING AND THEN THEY GET TO PICK
ONE OF THE MISSIONS.
SO WE MIGHT GO BACK -- IT'S
STILL A LONG TRIP.
TALKING ABOUT MAYBE A LAUNCH IN
THE MID 2020s.
YOU KNOW, '25, '26 AND THEN
MAYBE A DECADE OR TO GET BACK TO
SATURN.
IT'S NOT A QUICK TRIP TO GET IN.
>> CAN'T WAIT.
THANK YOU.
>> DON'T FORGET, URANUS AND
NEPTUNE.
THEY'RE OUT THERE TOO.
IT WOULD BE GREAT TO SEND A
FLAGSHIP MISSION LIKE CASSINI ON
OUT TO ONE OF THE ICE GIANTS.
URANUS OR NEPTUNE.
WE HAD TANTALIZING GLIMPSES.
MAYBE WE'LL HAVE A FLAG SHIP OUT
TO URANUS OR NEPTUNE.
>> I'LL JUMP IN FOR ONE MORE
QUESTION.
HOW LONG DOES IT TAKE FOR THE
IMAGE TO GET FROM CASSINI TO
EARTH?
LIKE TO GET THE DATA HERE?
AND MY iPHONE I THINK HAS EIGHT
MEGA PIXELS.
WHAT'S CASSINI HAVE?
>> ONE MEGA PIXEL.
>> ONE.
>> IT'S BLACK AND EXCITE.
>> OKAY.
>> WE COLORIZE OUR IMAGINES AND
IT TAKES 90 MINUTES FOR THE
IMAGE TO GET FROM CASSINI TO
EARTH.
>> THE WHOLE MEGA PIXEL --
>> WELL, THE MEGA PIXEL, LET'S
SEE.
WE DO 140 KILOBYTES PER SECOND.
THAT'S TEN SECONDS OR SO.
ROUGHLY.
LET'S SAY 20 COUNTING OVERHEAD
TO GET THE IMAGE DOWN HERE ONCE
IT STARTS.
SATURN IS AN HOUR AND A HALF
LIGHT TIME AWAY.
WHEN CASSINI STARTS TO SEND A
SIGNAL HER BITS DON'T GET TO THE
GROUND FOR AN HOUR AN A HALF.
>> HOUR AND A HALF.
>> IF WE WANT TO SEND SOMETHING
TO CASSINI TO IT HAVE ANSWERED
WE HAVE TO WAIT TWO OR THREE
HOURS.
>> WOW.
THAT WAS REALLY GREAT.
THANK YOU.
>> CASSINI HAS TO BE VERY SMART.
SHE HAS TO BASICALLY HAVE
COMMANDS ON BOARD TO KEEP HER
GOING TYPICALLY FOR TEN WEEKS AT
A TIME.
WHERE TO DEPLOY, WHERE TO LOOK,
WHEN TO SEND DATA BACK.
VERY SMART SPACECRAFT.
>> ACTUALLY, SPEAKING OF PHOTOS.
I WAS WONDERING WHAT THE PLAN
FOR THE GRAND FINALE, WHAT ARE
YOU EXPECTING TO SEE?
ARE YOU EXPECTING TO TAKE PHOTOS
OR EXPECTING TO SEE SOME
RESOLVING CONCEPT SO CLOSE OR
LOOKING AT THE CLOUDS OF SATURN
BECAUSE THE PERIAPSIS ARE SO
CLOSE?
ARE YOU GUYS EXPECTING TO TAKE A
LOT OF PHOTOS ON THIS MISSION?
>> WELL, WE'LL TAKE A LOT OF
PHOTOS OF BOTH THE RING AND THE
PLANET.
IT'S MILLIMETERS OR CENTIMETERS
IN SIZE.
WE STILL COULDN'T RESOLVE AN
INDIVIDUAL RING PARTICLE.
BUT WE COULD RESOLVE THE
STRUCTURE THAT WE SEE IN THE
RING.
THIS IS A CHANCE TO LOOK AT THAT
RESOLUTION, BUT ON THE LIGHTER
SIDE OF THE RINGS.
ALSO WE'LL GET CLOSE-UP VIEWS OF
THE PLANET, OF THE POLES, OF THE
ATMOSPHERE ITSELF.
I THINK THE SURPRISES ARE THE
QUESTIONS WE DON'T KNOW YET TO
ASK.
WHEN WE LOOK AT THE RINGS OR THE
PLANET, WHAT MIGHT WE SEE?
ALSO WE HAVE A DETECTER, SOME OF
THE TINY RING PARTICLES CHARGE
UP AND THEY'LL GO INTO ONE OF
THE SENSORS.
THE COSMIC DEPTH ANALYZER.
WE'LL GET THE DIRECT COMPOSITION
OF THE RINGS.
WE KNOW THEY'RE WATER ICE, BUT
WE DON'T KNOW IF THEY'RE SILL
ACAT, IRON.
SO WE'LL GET THE ANSWERS FOR
THAT FOR SURE FOR THE FIRST
TIME.
>> I MIGHT ALSO ADD AS WE ENTER
THE ATMOSPHERE, EVERYTHING IS
GOING TO BE FOCUSED ON
ATMOSPHERIC CONSTRUCTION AND
CONSTITUENTS.
SPECTROMETERS, THE FIELDS AND
PARTICLES THEY'LL BE POINTING AT
THE ATMOSPHERE.
THE CAMERA WILL BE POINTING SOME
PLACE ELSE AND FURTHERMORE IN
ORDER TO PLAY ALL THAT DATA BACK
AS FAST AS WE CAN, WE HAD TO
NARROW DOWN THE BAND WIDTH.
A MEGA PIXEL IS A MEGA PIXEL.
SO THE CAMERA IS NOT EVEN
RECORDING THIS AND BEING SENT
DOWN IN THE FINAL SECONDS.
>> THANK YOU.
>> YOU SAID IN RESPONSE TO THE
EARLIER QUESTION YOU'RE GETTING
PICTURES IN BLACK AND WHITE AND
THEN YOU'RE COLORING THEM WITH
FILTERS.
HOW DOES THAT WORK?
ARE YOU CHOOSING --
>> OUR CAMERAS HAVE TWO FILTER
WHEELS.
YOU KNOW, ESSENTIALLY YOU CAN
TAKE A GREEN, BLUE AND
MAGENTA -- NOT MAGENTA.
WHATEVER THE THREE COLORS YOU
PICK AND COLORIZE THEM.
IT HAS INFRARED FILTERS THAT
PENETRATE THE HAZE, SO EACH OF
THE FILTER WHEELS YOU ACTUALLY
ROTATE THAT FILTER INTO THE
IMAGE PATH.
TAKE AN IMAGE, THEN ROTATE IT
AND THEN THEY'RE COMBINED AND
COLORIZED ON THE GROUND.
>> SO THE COLORS REPRESENT WHAT
YOU'RE LOOKING AT?
>> THEY CAN.
BUT THEY CAN REPRESENT THE RED
HURRICANES AND THINGS LIKE THAT
THAT ACCENTUATE LEVELS OF
ELEVATION OR OF CHEMICAL
CONSTITUENTS.
SOME WERE NATURAL AND SOME WERE
FALSE COLORED TO HIGHLIGHT
WHATEVER ITEMS YOU'RE TRYING TO
LOOK AT.
>> BUT YOU CAN GET TRUE COLOR.
YOU TAKE THE FILTERS AND ADD
THEM TOGETHER AND YOU GET THE
TRUE COLOR YOU SEE WITH YOUR
EYES IN THE PICTURES.
>> THANK YOU.
>> HI.
THANK YOU FOR YOUR
PRESENTATIONS.
I HAVE TWO QUESTIONS HERE I WANT
TO ASK.
FIRST IS -- YOU GUYS SAID THAT
CASSINI SATELLITE -- I MEAN THE
CASSINI -- WHATEVER IS THE
FARTHEST FROM THE SOLAR SYSTEM
THAT WE HAVE EVER GONE.
>> OH, NO.
>> NO NO.
WHAT I SAID THAT THAT HUYGENS
LANDING ON THE SURFACE OF TITANS
IS THE FURTHEST WE HAVE LANDED A
PROBE ON THE SURFACE BUT THE
FURTHEST SPACECRAFT FROM THE SUN
IS THE VOYAGER SPACECRAFT.
THEY'RE WELL PAST THE ORBITS,
NEPTUNE, PLUTO, ON OUT.
ONE INTO INTER STELLAR WINDS.
>> THEY'RE A DAY AND A HALF TO
GET BACK TO THE EARTH.
THEY'RE WAY OUT THERE.
>> I SEE.
THE OTHER QUESTION I HAVE IS --
IF I REMEMBER CORRECTLY SATURN
HAS FIVE BIG MOONS.
>> CORRECT.
>> AND SO WHY DO YOU ONLY LAND
ON TWO OF THOSE MOONS?
>> WELL, TITAN IS THE VERY
BIGGEST MOON AND IT'S THE ONLY
MOON IN OUR SOLAR SYSTEM WITH A
THICK ATMOSPHERE.
IT WAS THE ONE THAT HAD THE MOST
QUESTIONS AND PUZZLES ABOUT IT.
SO WE REALLY HAD TO WAIT ON
CASSINI TO CARRY THIS SINGLE
PROBE AND SO IT WAS EASIEST TO
LAND ON TITAN.
YOU COULD LAND WITH A PARACHUTE.
YOU DIDN'T NEED ROCKETS OR
ANYTHING FANCY AND WE WANTED TO
SEE WHAT THAT SURFACE LOOK LIKE.
IF WE GO BACK WE COULD CARRY
PROBES THAT COULD LAND ON
MULTIPLE MOONS AND LOOK AT THOSE
AS WELL.
>> OKAY.
SO YOU MEAN THAT YOU CHOOSE THE
MOONS YOU WANT TO LAND ON
BEFORE?
>> RIGHT.
WE CHOSE TITAN BEFORE CASSINI
EVEN LAUNCHED WE HAD CHOSEN
TITAN.
>> I SEE.
THANK YOU.
>> THANK YOU FOR THE VERY
AMAZING TALK.
I HAD A QUESTION ON THE RADIO
APPLICATION.
FOR THE THREE DIFFERENT
FREQUENCIES THAT YOU HAD
AVAILABLE ON THE SPACECRAFT, CAN
YOU CHARACTERIZE A LITTLE BIT ON
RING PARTICLES THAT ARE SMALLER
THAN THE SHORTEST WAVE LENGTH
AND LARGER THAN THE LONGER
WAVELENGTHS AND THE DEFRACTION
PATTERNS AND HOW WE'D BE ABLE TO
ASCERTAIN THE PARTICLE
POPULATION.
>> THE THREE WAVE LENGTHS OF THE
RADIO SCIENCE ARE VERY
DIAGNOSTICS IN HELPING US
UNDERSTAND THE RING PARTICLES
AND THEY'RE SEEING ALL OF THE
PARTICLES IN THE PARTICULAR SIZE
RANGE FOR THAT.
SO THEY DO A GOOD JOB.
THE KA, THE X BAND AND F BAND IN
LOOKING NOW THE RINGS.
SOMETIMES THE S BAND SIGNAL IS
BLOCKED OUT FIRST BECAUSE THE
RINGS ARE SO OPTICALLY THICK.
>> HOW DOES THE DEFRACTURE ON
DISBURRTION OCCUR?
>> WELL, THE RADIO SCIENCE --
FAIRLY LARGE FIELD OF VIEW.
SO IT'S INTEGRATED PARTICLES ALL
THE WAY ACROSS THAT FIELD OF
VIEW.
SOMETIMES WE SEE DEFRACTION
PATTERNS THAT TELL US THE RING
PARTICLES ARE LINING UP AND
STRUCTURED IN A CERTAIN WAY.
IT CAN ACTUALLY DO SOME WORK TO
DETECT THOSE AND RADIO SCIENCE
AS WELL.
IF YOU WANT MORE DETAIL ANSWERS
I CAN GIVE THOSE IF YOU WANT TO
COME UP AFTERWARDS.
>> THANK YOU.
THIS IS MORE OF AN ENGINEERING
THAN A SCIENCE QUESTION, BUT FOR
ALL THE MANEUVER HOW DO YOU KNOW
YOU'RE POSITIONED ACCURATELY
ENOUGH TO PERFORM THE MANEUVERS?
BECAUSE YOU CAN'T EXACTLY GET
YOUR GPS --
>> I HAVE TO BRAG A LITTLE BIT
BECAUSE JPL IS THE ABSOLUTE
CENTER FOR NAVIGATION.
WE USE DOPPLER AND WE USE
RANGING TO MEASURE THE VELOCITY
AND WE FIT THAT TO THE ORBIT.
AT THE SAME TIME, WE'RE SOLVING
FOR ALL OF THE POSITIONAL OF ALL
THE SATELLITES ON SAT YOU WERE.
THAT'S A DAILY PROCESS.
WE'LL DO ONE TONIGHT BASED ON
THE LATEST OPERATIONS.
YOU KNOW, WE'RE MOVING A
KILOMETER OR MAYBE A FEW HUNDRED
METERS JUST BEING PUSHED AROUND
BY OUR OWN SHENANIGANS AS WELL
AS SMALLER FORCES.
SO WE'RE CONSTANTLY TRACKING THE
SPACECRAFT.
AND OVER THE DECADES, YOU KNOW,
WE HAVE HIT COMETS.
I GOT TO SAY THAT THE NAVIGATION
THAT SAT -- OF SATURN IS ONE OF
THE TRIUMPHS OF INTERPLANETARY
NAVIGATION, BECAUSE THE
PRECISION YOU COULD DO THE SAME
THING WITH MUCH COARSER
MEASUREMENTS BUT YOU HAVE TO BE
CARRYING MORE AND YOU HAVE TO
GET BACK ON TRACK.
I CAN SHARE A LOT OF PAPERS
ABOUT THIS.
>> ONE OF THE NAVIGATION -- IT'S
ALLOWED US TO GO CLOSER AND
CLOSER AND CLOSER TO THE TARGETS
UNTIL WE CAME WITHIN THE 50
KILOMETERS OF THE SOUTH POLE OF
THE ENCELADUS.
IN FACT OUR CLOSEST FLY BY WAS
25 KILOMETERS.
SO WE HAVE GOTTEN SO GOOD, WE
CAN GO CLOSE.
KNOW WHERE WE'RE GOING TO HIT
AND WE DON'T MISS.
>> THANKS.
>> I HAVE SOME ONLINE QUESTIONS
HERE.
I WANT TO GO THROUGH A COUPLE OF
THOSE.
A QUESTION FROM TITAN 82.
WANTS TO KNOW WHAT IS THE
TEMPERATURE OF SURFACE -- SUB
SURFACE OCEAN OF ENCELADUS?
WELL, IF IT'S TRUE WE HAVE
HYDROTHERMAL VENTS IT MIGHT BE
AS CLOSE TO THE BOILING POINT,
BUT CLEARLY IF THE WATER IS
LIQUID AND IF IT'S UNDER
PRESSURE WITH AMMONIA, IT MUST
BE ABOVE THE FREEZING POINT OF
WATER.
SO WE KNOW THAT -- OTHERWISE THE
OCEAN WOULDN'T BE A LIQUID.
NEXT QUESTION, WILL CASSINI BE
ABLE TO PHOTOGRAPH THE VERTICAL
RING STRUCTURES AS IT PASSES
THROUGH THE RING PLANES?
A GREAT QUESTION.
BUT UNFORTUNATELY THE ANSWER IS
NO.
WE CAN'T PHOTOGRAPH THE VERTICAL
STRUCTURES VERY WELL BECAUSE
THEY'RE NOT VERY BIG.
WE DON'T THINK WE CAN RESOLVE IT
A KILOMETER OR LESS.
WE DON'T THINK WE'LL GET THE
CLOSEST TO THE RING.
SO I'M SURE WE'LL BE LOOKING.
IN FACT, WE HAVE LOOKED AS WE
HAVE GONE THROUGH THE RING PLANE
CROSSINGS.
I DON'T THINK WE'LL HAVE THE
RESOLUTION TO BE ABLE TO DO
THAT.
AND THEN IF WE WANT TO LOOK FOR
SHADOWS WHICH IS A GREAT WAY TO
LOOK FOR THE STRUCTURE DURING
THIS POINT IN THE MISSION,
THAT'S NO SHADOWS CAST BY THE
RING PARTICLES.
WE'RE NOT AN EQUINOX.
OKAY.
ANY OTHER QUESTIONS?
OKAY.
IF NOT, THANK YOU VERY MUCH.
