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THIS... IS OUR COSMIC NEIGHBORHOOD.
ONE STAR, THE SUN...
4 ROCKY PLANETS... INCLUDING OUR HOME, THE EARTH...
4 GAS GIANTS...
AND ONE ICE WORLD WITH A LARGE MOON.
IN BETWEEN, ASTEROIDS, TUMBLING END OVER END...
AND COMETS GROWING LONG TAILS OF GAS AND DUST AS THEY APPROACH THE SUN.
title: A FAMILY PORTRAIT
IN THIS VIDEO, "A FAMILY PORTRAIT" OF THE MEMBERS OF OUR SOLAR SYSTEM, AND AMAZING CLOSE-UPS OF THEIR DISTINCTIVE FACES...
title: BIRTH AND EVOLUTION OF THE SOLAR SYSTEM
WE'LL DISCOVER HOW OUR SOLAR SYSTEM BEGAN... AND THE PLANETARY PROCESSES WHICH HAVE SHAPED OUR COSMIC NEIGHBORHOOD...
title: OTHER WORLDS
...AND WE'LL FIND OUT THAT-FOR THE FIRST TIME-WE'VE NOW GOT FIRM EVIDENCE OF OTHER WORLDS, NEW SOLAR SYSTEMS, BEYOND OUR OWN.
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main titles
program 1
SOLAR SYSTEMS
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IN 1977, TWO SPACECRAFT BEGAN AN EPIC JOURNEY OF DISCOVERY THAT WOULD TAKE THEM MUCH FARTHER THAN ANY COLUMBUS DOWN HERE ON EARTH.
THEY WERE CALLED, APPROPRIATELY, "VOYAGER 1"
...AND "VOYAGER 2."
VOYAGER 2 TOOK ADVANTAGE OF A RARE ALIGNMENT OF THE PLANETS TO BORROW GRAVITATIONAL ENERGY FROM EACH ENCOUNTER, AND SLINGSHOT ITSELF ONWARD TO VISIT ALL THE GIANT PLANETS.
JUST BEFORE VOYAGER 1 PASSED BEYOND OUR SOLAR SYSTEM EN ROUTE TO THE STARS, ASTRONOMERS ON THE IMAGING TEAM SUGGESTED TURNING IT AROUND FOR THE FIRST-EVER "FAMILY PORTRAIT" OF OUR SOLAR SYSTEM.
title: GAS GIANTS
THE CAMERA PANNED ACROSS THE SKY, CAPTURING "LONG SHOTS" OF OUR SYSTEM'S 4 GAS GIANTS... URANUS... NEPTUNE... SATURN... JUPITER.
title: TERRESTRIAL PLANETS
THEN, FAR TINIER AND HARDER TO SEE, THE 4 "TERRESTIAL" OR EARTH-LIKE PLANETS... MARS, EARTH, VENUS AND MERCURY.
BACK THERE, AT THE CENTER, OUR SUN, LOOKING JUST LIKE THE AVERAGE STAR IT IS.
LEFT OUT OF THIS PICTURE, ICY PLUTO-THE 9TH PLANET.
THE VOYAGER IMAGES SHOWED US HOW VAST SPACE IS, AND HOW SMALL AND ISOLATED OUR SOLAR SYSTEM.
BUT IT ALSO SHOWED US THAT IT IS A SYSTEM... CIRCLING ROUND OUR STAR, BOUND TOGETHER BY THE MASTER FORCE OF GRAVITY.
LET'S MEET THE MEMBERS OF OUR FAMILY, IN CLOSE-UP.
AT THE HEART OF THE SOLAR SYSTEM IS OUR STAR, THE SUN.
title 99.8% OF OUR SOLAR SYSTEM'S MASS
THE SUN CONTAINS 99.8 PER CENT OF ALL THE MASS IN OUR SOLAR SYSTEM.
ONE MILLION EARTHS COULD FIT INSIDE THE SUN.
ITS VISIBLE SURFACE IS NEARLY 6,000 DEGREES KELVIN.
THE SUN'S LIGHT AND HEAT POWER LIFE ON EARTH... AND ITS RADIATION STRETCHES OUT TO THE VERY EDGE OF THE SOLAR SYSTEM, WHERE THE REALM OF THE SUN BECOMES INTER-STELLAR SPACE.
NEXT OUT FROM THE SUN, MERCURY, REVOLVING ONCE AROUND THE SUN EVERY 88 DAYS IN A VERY ELLIPTICAL ORBIT.
2ND SMALLEST OF THE PLANETS, TEMPERATURES VARY FROM 400 DEGREES CELSIUS TO MINUS 170, DEPENDING ON WHICH HEAVILY CRATERED FACE LOOKS T'WARD THE SUN.
2ND ROCK FROM THE SUN, VENUS.
IT'S ABOUT THE SAME SIZE AS EARTH, BUT IT'S A HOT AND HELLISH WORLD, WITH THICK CLOUDS OF SULPHURIC ACID, AND SURFACE TEMPERATURES OF OVER 450 DEGREES CENTIGRADE.
A RUNAWAY GREENHOUSE EFFECT MAKES VENUS HOTTER THAN MERCURY EVEN THOUGH IT'S TWICE AS FAR FROM THE SUN.
THE MAGELLAN SPACECRAFT USED RADAR TO PEER THROUGH THE CLOUDS, REVEALING MORE THAN 100,000 VOLCANOES, AND A MOUNTAIN TALLER THAN MOUNT EVEREST.
3RD ROCK, EARTH...
UNIQUE IN THE SOLAR SYSTEM FOR PLENTIFUL LIQUID WATER ON ITS SURFACE AND, AS YET, THE ONLY PLANET WHERE WE KNOW FOR SURE THAT LIFE BEGAN AND EVOLVED.
PERHAPS BY UNDERSTANDING THE PLANETARY PROCESSES THAT HAVE SHAPED OUR NEIGHBORS, WE'LL BE ABLE TO KEEP OUR HOME WORLD HABITABLE...
name title:
CLAUDIA ALEXANDER
U.S. Project Scientist, ROSETTA Comet mission
Jet Propulsion Laboratory, NASA/Caltech
...over the long term the Earth has changed so frequently in geologic time and we want to be prepared for what's coming next. Is there global warming? Is there going to be another Ice Age? And what other kinds of changes are there that we don't know about? Are there a special kind of volcanic explosions that could completely change our climate that we're not aware of?
It's by studying other planets like Venus that we take a fresh look at the Earth and we say "Holy Mackerel", you know, we saw this... what we call a "super volcano", and now when we look down on Earth... it's giving us a whole totally fresh idea about the potential changes that might happen on Earth that could be ...have very significant effects on our lives.
ONE OUT FROM EARTH, MARS, THE RED PLANET... NOW LOCKED IN AN ICY DEEP-FREEZE.
HALF THE SIZE OF EARTH, MARS HAS GIANT VOLCANOES...
A VAST CANYON THAT WOULD STRETCH CLEAR ACROSS NORTH AMERICA...
EVIDENCE OF RUNNING WATER FROM LONG AGO...
AND PERHAPS, STILL, LIQUID WATER DEEP UNDERGROUND.
IMAGES FROM THE RECENT GLOBAL SURVEYOR AND PATHFINDER MISSIONS MAKE US WANT TO VISIT MARS AGAIN WITH ROVERS AND SOON WITH HUMAN EXPLORERS, TO FIND OUT WHETHER LIFE EVER BEGAN HERE, AND-PERHAPS-STILL LINGERS IN SOME HOSPITABLE OASIS.
BETWEEN MARS AND JUPITER... THE ASTEROID BELT, TUMBLING LEFT-OVERS OF PLANETS THAT NEVER QUITE GOT IT TOGETHER... OR REMNANTS OF WORLDS THAT FELL APART.
THEN, THE 4 GAS GIANTS, STUDIED IN DETAIL BY THE VOYAGER SPACECRAFT...
JUPITER, KING OF THE PLANETS, 2ND MOST MASSIVE OBJECT IN OUR SYSTEM AFTER THE SUN.
PERHAPS THERE'S A SOLID CORE OF ROCK AND LIQUID METAL, BUT HERE THE SURFACE IS ALL CLOUDS IN MOTION, INCLUDING THIS SWIRLING HURRICANE-THE "GREAT RED SPOT"-A STORM THAT HAS LASTED MORE THAN 300 YEARS.
VOYAGER SHOWED US THAT JUPITER'S MOONS ARE AS EXCITING AND DYNAMIC AS THE PLANET ITSELF...
IN ALL JUPITER HAS MORE THAN 17 MOONS-STAY TUNED FOR MORE!!!-AND A FAINT RING SYSTEM...
NEXT OUT, SATURN WITH THE LARGEST AND MOST FINELY-PATTERNED RINGS IN OUR SOLAR SYSTEM.
ALSO A GAS GIANT, SATURN IS SQUASHED, SMALLER FROM POLE TO POLE THAN AROUND ITS EQUATOR.
VOYAGER 2 USED SATURN'S GRAVITY TO BOOST IT ON TO URANUS
LIKE THE OTHER GAS GIANTS, URANUS HAS RINGS... AND MORE THAN 20 MOONS-THE MOST OF ANY PLANET IN THE SOLAR SYSTEM.
LAST GAS GIANT, NEPTUNE, NAMED FOR THE GOD OF THE SEA AND-APPROPRIATELY, BLUE-ISH IN COLOR.
NEPTUNE HAS THE FASTEST WINDS IN THE SOLAR SYSTEM, MORE THAN 24 HUNDRED KILOMETERS PER HOUR, AND THIS "GREAT DARK SPOT".SEEN BY VOYAGER, NOW SEEMS TO HAVE DISAPPEARED.
USUALLY THE OUTERMOST, AND CERTAINLY THE SMALLEST PLANET IN OUR SOLAR SYSTEM IS PLUTO... THE ONLY WORLD NEVER VISITED, SO FAR, BY A SPACECRAFT FROM EARTH.
PLUTO IS MYSTERIOUS, BUT WE DO KNOW IT HAS A MOON, CHARON, ABOUT A THIRD ITS SIZE, THE LARGEST SATELLITE, RELATIVE TO ITS PARENT PLANET, IN THE SOLAR SYSTEM.
name title:
WAYNE LEE, Mission Designer
Jet Propulsion Laboratory, NASA/Caltech
The most noticeable force that shapes our solar system, of course, is gravity, uh... Gravity is what keeps all the planets in orbit around the Sun. It's what keeps us, uh, glued down to the surface of the Earth. It keeps us from floating away as we're trying to walk to school every day. It keeps your peas on your dinner plate so you can eat them. It turns out that if the Sun did not pull on the planets with its gravitational force, they would just fly off into the Universe never to be seen from again.
I'd say the second fundamental force that shapes the solar system is probably what we call the "nuclear force." And the nuclear force is what allows fusion to occur inside, deep inside the Sun. And, of course, nuclear fusion is the process that produces ...the heat and light that comes out of the sun and warms all the planets.
title: GRAVITY
title: FUSION
GRAVITY... AND NUCLEAR FUSION IN A STAR...
THESE ARE THE FORCES OF NATURE WHICH MAKE AND SHAPE A SOLAR SYSTEM... AND THE RESULT?
...NINE PLANETS, MILLIONS OF ASTEROIDS AND COMETS
...AND, DOWN HERE ON EARTH, LIFE, CONSCIOUSNESS AND CURIOSITY...
chapter head title: THE BIRTH AND EVOLUTION OF THE SOLAR SYSTEM
WHERE DID ALL THIS COME FROM... WHEN DID IT BEGIN?
THAT'S RIGHT... THE SCREEN IS DARK.
AS FAR AS WE KNOW, OUR UNIVERSE ORIGINATED FROM "NOTHING."
THEN IN AN INSTANT...
(explosion)
...SPACE AND TIME BEGAN.
WE CALL THIS..."THE BIG BANG"...AND DATE IT AT ABOUT 15 BILLION YEARS AGO.
FROM A POINT SMALLER THAN AN ATOM, EVERYTHING LEAPT INTO BEING, FIRST AS PURE ENERGY...
THEN, AFTER SEVERAL HUNDRED THOUSAND YEARS, MATTER CONDENSED AND STRUCTURE BEGAN TO DEVELOP.
GALAXIES AND STARS EMERGED FROM PRIMORDIAL CHAOS.
STARS ARE BORN WHEN GRAVITY DRAWS IN GAS AND DUST.
IN THEIR CORES, HYDROGEN-THE SIMPLEST ELEMENT IN THE UNIVERSE-FUSES TOGETHER IN THERMO-NUCLEAR REACTIONS TO FORM HELIUM, RELEASING ENERGY.
SOME STARS ARE SO LARGE THAT AFTER A LIFETIME OF BUILDING UP HEAVIER ELEMENTS LIKE IRON, THEY DIE IN COLOSSAL >SUPERNOVA< EXPLOSIONS.
SUPERNOVAS ENRICH THE CLOUDS OF INTERSTELLAR GAS AND, PERHAPS, TRIGGER THE NEXT GENERATION OF STAR FORMATION.
THIS IS HOW WE THINK OUR SOLAR SYSTEM BEGAN.
FIRST, OUR STAR, THE SUN, TURNS ON, SOME 4 TO 5 BILLION YEARS AGO.
INSTABILITIES FARTHER OUT IN THE DISK CAUSE REGIONS OF MATTER TO CONDENSE AND GROW.
TOO SMALL TO BECOME STARS, THESE WILL BE PLANETS.
CLOSE TO THE SUN, THEY'RE MADE OF ROCK, IRON AND OTHER SOLID MATTER.
THE YOUNG SUN BLOWS AWAY MUCH OF THE ORIGINAL GAS, LEAVING AT MOST A THIN ATMOSPHERE.
FARTHER OUT, WHAT WILL BECOME THE GIANT PLANETS RETAIN MUCH OF THE GAS THAT GAVE THEM BIRTH.
THIS YOUNG SOLAR SYSTEM WAS A PLACE OF TREMENDOUS VIOLENCE.
OBJECTS TOO SMALL TO BE PLANETS SMASH INTO LARGER ONES, LEAVING THE VAST NUMBERS OF CRATERS STILL TO BE SEEN ON THE MOON AND MERCURY.
PLANETS LIKE EARTH AND MARS WERE LARGE ENOUGH NOT SPLIT APART...
AND BIG ENOUGH TO GENERATE HEAT IN THEIR ROCK AND METAL CORES.
VOLCANOES SPEWED OUT GASES INTO NEW ATMOSPHERES...
HYDROGEN AND OXYGEN BECOME LIQUID WATER...
COMETS DELIVER ICES AND ORGANIC MOLECULES FROM FARTHER OUT IN THE SOLAR SYSTEM.
JUST A FEW HUNDRED MILLION YEARS AFTER EARTH FORMED, LIFE BEGAN-AS WE CAN SEE IN FOSSIL STROMATOLITES.
4 CENTURIES AGO, GALILEO TURNED A TELESCOPE TO THE HEAVENS, AND DISCOVERED CRATERS ON THE MOON AND SUNSPOTS ON OUR LOCAL STAR.
ONE CENTURY AGO, THE AMERICAN, ROBERT GODDARD, BEGAN EXPERIMENTS IN ROCKETRY...
50 YEARS AGO, THE SPACE AGE BEGAN... AND GERMAN, RUSSIAN AND AMERICAN ENGINEERS BUILT THE MACHINES THAT WOULD TAKE HUMANS INTO ORBIT.
NOW WE HAVE TOOLS LIKE "PATHFINDER" TO EXPLORE OUR SOLAR SYSTEM, AND CAN SHARE IN THE EXHILARATION OF SEEING NEW WORLDS.
SO, HERE'S OUR COSMIC ADDRESS...
WE ORBIT AN AVERAGE, YELLOW-DWARF STAR, WHICH WE EXPECT TO KEEP BURNING FOR ANOTHER 5 BILLION YEARS.
OUR STAR IS ONE OF ABOUT 100 BILLION STARS-THAT'S ONE FOLLOWED BY 11 ZEROES-IN A VAST SPIRAL WE CALL THE MILKY WAY GALAXY.
THE MILKY WAY, IN TURN, IS ONE OF 30 GALAXIES HELD RELATIVELY CLOSE TOGETHER BY GRAVITY, KNOWN AS "THE LOCAL GROUP."
BUT THE MILKY WAY IS BUT ONE OF PERHAPS 100 BILLION GALAXIES IN THE KNOWN UNIVERSE...
AND IN THAT VASTNESS OF SPACE AND TIME, WE'RE BEGINNING TO DISCOVER THAT OUR SOLAR SYSTEM IS NOT ALONE.
chapter head title:
OTHER WORLDS
IT'S NOT EASY TO FIND PLANETS AROUND OTHER STARS.
IN THE VISIBLE LIGHT WHICH OUR EYES AND TELESCOPES CAN SEE, A STAR OUTSHINES ANY PLANETS CLOSE TO IT BY A BILLION TO ONE, MAKING IT IMPOSSIBLE TO VISUALIZE FROM EARTH.
BUT OVER THE PAST DECADE, ASTRONOMERS HAVE USED INGENIOUS METHODS TO DETECT MINUTE WOBBLES IN DISTANT STARS, CAUSED BY THE FAINT GRAVITATIONAL TUG OF PLANETS ORBITING THEM.
BY MID-2000 FORTY PLUS PLANETS HAD BEEN DISCOVERED WITH METHODS LIKE THESE... INCLUDING WORLDS THAT ARE SMALLER THAN SATURN, AND WHICH MAY HAVE RINGS AND MOONS JUST LIKE THE PLANETS OF OUR OWN SOLAR SYSTEM.
IN SPRING 2000, NASA ANNOUNCED THE DISCOVERY OF 2 MORE PLANETS DETECTED BY MINUTE VARIATIONS IN A STAR'S MOTION AND LIGHT.
name title:
GEOFFREY MARCY
Prof. of Astronomy, Univ. of California, Berkeley
We are measuring the velocities of stars to plus or minus 3 meters per second, which is sort of bicycle speed. These stars are enormous spheres a million times bigger than the Earth. They are 2 or 300 light years away, and these globes of gas can be measured to plus or minus bicycling speed! But we are at that point and what we would like to do is measure the speed to stars even more accurately, to human walking speed, about 1 meter per second.
name title:
CHRIS CHYBA
Carl Sagan Chair for Study of Life in the Universe, SETI Institute
I think that we're going to find that just about every kind of solar system that could be out there is out there. So our solar system is going to be one of a huge variety of possibilities. Some of them are going to be good for the possibility of life, and some of them aren't going to be good for life at all, but everything's going to be out there.
Claudia Alexander:
I think that we will discover life outside of Earth, extraterrestrial life. I feel very strongly that we will discover it in the next 20 years...
Chyba:
...We've been speculating, are there other worlds like the Earth, are there other solar systems, or are we unique? The exciting thing about what's happening now is that we're beginning to find out and we are going to know in the next few decades whether the Earth is common or rare.
