1 00:00:01,200 --> 00:00:04,000 Narrator: DAZZLING, LEGENDARY -- 2 00:00:04,000 --> 00:00:07,467 IT'S THE MOST BEAUTIFUL PLANET IN THE NIGHT SKY. 3 00:00:07,467 --> 00:00:10,933 BUT SECRETIVE SATURN HAS BEEN HOLDING OUT ON US. 4 00:00:10,933 --> 00:00:13,267 WE LEARNED A VAST AMOUNT ABOUT IT, 5 00:00:13,267 --> 00:00:16,500 AND MOST OF THIS HAS BEEN VERY SURPRISING. 6 00:00:16,500 --> 00:00:19,867 WE THOUGHT WE KNEW THOSE BODIES. WE HAD NO IDEA. 7 00:00:19,867 --> 00:00:23,567 Narrator: SATURN BOILS WITH EXTREME WEATHER 8 00:00:23,567 --> 00:00:25,133 AND WEIRD LIGHTS. 9 00:00:25,133 --> 00:00:27,533 THE RINGS RIPPLE AND TWIST, 10 00:00:27,533 --> 00:00:30,667 BULLIED BY OVER 60 REMARKABLE MOONS. 11 00:00:30,667 --> 00:00:35,367 THEY ARE INDIVIDUAL WORLDS. THEY EACH HAVE A STORY TO TELL. 12 00:00:35,367 --> 00:00:37,167 THIS IS A PLANETARY EXPLORER'S DREAM. 13 00:00:37,167 --> 00:00:39,133 Narrator: TODAY, SATURN'S MOONS 14 00:00:39,133 --> 00:00:42,267 ARE THE HOTTEST PROPERTY IN THE SEARCH FOR ALIEN LIFE. 15 00:00:42,267 --> 00:00:44,667 IF THERE'S ONE PLACE IN THE SOLAR SYSTEM 16 00:00:44,667 --> 00:00:47,367 I WOULD PUT A BET THAT LIFE EXISTS THERE RIGHT NOW, 17 00:00:47,367 --> 00:00:48,533 I WOULD CHOOSE SATURN. 18 00:00:48,533 --> 00:00:50,567 Narrator: AND ON SATURN'S LARGEST MOON, 19 00:00:50,567 --> 00:00:53,567 WE MAY HAVE ALREADY FOUND IT. 20 00:00:53,567 --> 00:00:55,100 WE'VE FOUND SOME CURIOUS THINGS ON TITAN, 21 00:00:55,100 --> 00:00:57,267 AND IT MIGHT JUST BE EVIDENCE OF LIFE. 22 00:00:57,267 --> 00:01:00,333 *** 23 00:01:00,333 --> 00:01:03,267 -- Captions by VITAC -- www.vitac.com 24 00:01:03,267 --> 00:01:06,300 CAPTIONS PAID FOR BY DISCOVERY COMMUNICATIONS 25 00:01:14,100 --> 00:01:16,933 Narrator: SATURN, THE JEWEL OF THE NIGHT SKY, 26 00:01:16,933 --> 00:01:20,600 DAZZLES US WITH ITS BEAUTY AND SCALE. 27 00:01:22,800 --> 00:01:24,500 IT'S HUGE -- SO BIG, 28 00:01:24,500 --> 00:01:29,400 YOU COULD FIT MORE THAN 700 EARTHS INSIDE IT. 29 00:01:29,400 --> 00:01:32,733 BUT DON'T LET SIZE FOOL YOU. 30 00:01:32,733 --> 00:01:34,567 Plait: ONE OF THE MOST INTERESTING THINGS ABOUT SATURN 31 00:01:34,567 --> 00:01:38,467 IS THAT IT IS SO BIG COMPARED TO HOW MUCH STUFF IS IN IT, 32 00:01:38,467 --> 00:01:41,067 THAT IT'S ACTUALLY LOWER DENSITY THAN WATER. 33 00:01:41,067 --> 00:01:44,433 THE OLD JOKE IS THAT IF YOU COULD FIND A BATHTUB BIG ENOUGH 34 00:01:44,433 --> 00:01:45,800 AND FILL IT WITH WATER, 35 00:01:45,800 --> 00:01:48,533 SATURN WOULD FLOAT, BUT IT WOULD LEAVE A RING. 36 00:01:48,533 --> 00:01:51,467 Narrator: OTHER PLANETS HAVE RINGS, 37 00:01:51,467 --> 00:01:55,467 BUT NONE SO VAST AND GLORIOUS AS SATURN'S. 38 00:01:55,467 --> 00:01:57,600 THE JOURNEY FROM THE OUTSIDE OF THE MAIN RINGS 39 00:01:57,600 --> 00:02:01,500 TO THE INSIDE EDGE IS 66,000 MILES -- 40 00:02:01,500 --> 00:02:04,800 OVER 2 1/2 TIMES THE DISTANCE AROUND THE EARTH. 41 00:02:04,800 --> 00:02:08,467 YET THIS VAST COLLECTION OF DUST AND ICE PARTICLES 42 00:02:08,467 --> 00:02:13,100 IS WHISPER-THIN IN PLACES JUST TENS OF FEET. 43 00:02:13,100 --> 00:02:14,900 Thaller: SATURN'S RINGS ARE MADE UP 44 00:02:14,900 --> 00:02:16,900 OF MOSTLY VERY SMALL PARTICLES, OF ICE AND ROCK. 45 00:02:16,900 --> 00:02:18,867 SOME OF THE PARTICLES ARE LARGER, 46 00:02:18,867 --> 00:02:21,367 BUT FOR THE MOST PART, NO BIGGER THAN GRAINS OF DUST. 47 00:02:23,900 --> 00:02:25,233 Narrator: RACING WITHIN THE RINGS 48 00:02:25,233 --> 00:02:27,933 AND ORBITING FAR OUTSIDE THEM ARE OVER 60 MOONS 49 00:02:27,933 --> 00:02:32,433 MADE FROM ROCK AND WATER ICE. 50 00:02:32,433 --> 00:02:35,533 THEY RANGE IN SIZE FROM TINY SNOWBALLS 51 00:02:35,533 --> 00:02:39,333 TO WORLDS WITH ACTIVE GEOLOGY, 52 00:02:39,333 --> 00:02:42,733 LIQUID WATER... 53 00:02:42,733 --> 00:02:46,233 WEATHER SYSTEMS, AND POSSIBLY EVEN LIFE, 54 00:02:46,233 --> 00:02:50,333 A BILLION MILES FROM THE WARMTH OF THE SUN. 55 00:02:50,333 --> 00:02:51,833 Porco: IT'S SO COLD OUT THERE, 56 00:02:51,833 --> 00:02:53,200 WE JUST THOUGHT THERE'D BE NOTHING THERE, 57 00:02:53,200 --> 00:02:56,133 AND WE WERE SO WRONG. WE WERE SO WRONG. 58 00:02:58,500 --> 00:03:01,167 [ LIGHTNING CRACKLING ] 59 00:03:01,167 --> 00:03:03,300 Narrator: SATURN'S FIRST SHOCKER -- 60 00:03:03,300 --> 00:03:04,867 ITS WILD WEATHER. 61 00:03:04,867 --> 00:03:08,833 [ CRACKLING AND WHOOSHING ] 62 00:03:08,833 --> 00:03:12,200 Kaku: THE STORMS ON SATURN ARE EXTREMELY VIOLENT, 63 00:03:12,200 --> 00:03:14,067 UNLIKE ANYTHING WE SEE ON THE PLANET EARTH. 64 00:03:14,067 --> 00:03:17,733 IN FACT, SATURN HAS THE SECOND FASTEST WINDS 65 00:03:17,733 --> 00:03:20,667 IN THE ENTIRE SOLAR SYSTEM. 66 00:03:20,667 --> 00:03:22,067 [ THUNDERCLAP ] 67 00:03:22,067 --> 00:03:25,267 Narrator: THESE WINDS RACE THROUGH SATURN'S CLOUD TOPS 68 00:03:25,267 --> 00:03:27,100 AT OVER A THOUSAND MILES AN HOUR, 69 00:03:27,100 --> 00:03:30,067 FOUR TIMES FASTER THAN EARTH'S STRONGEST CYCLONES. 70 00:03:30,067 --> 00:03:32,500 [ THUNDERCLAPS ] 71 00:03:32,500 --> 00:03:37,133 AND LIGHTNING BOLTS FLASH UP TO 10,000 TIMES MORE POWERFULLY 72 00:03:37,133 --> 00:03:38,867 THAN THOSE ON EARTH. 73 00:03:40,400 --> 00:03:42,867 Porco: EVERYTHING ON SATURN IS JUST SO VERY, VERY MUCH BIGGER. 74 00:03:42,867 --> 00:03:44,333 I MEAN, THERE ARE WEATHER SYSTEMS 75 00:03:44,333 --> 00:03:46,800 THAT ARE AS BIG OR BIGGER THAN THE EARTH. 76 00:03:46,800 --> 00:03:50,500 Narrator: SATURN'S FEROCIOUS WEATHER IS SURPRISING, 77 00:03:50,500 --> 00:03:53,233 BECAUSE ON EARTH, WEATHER IS DRIVEN 78 00:03:53,233 --> 00:03:55,900 BY THE HEAT ENERGY OF THE SUN. 79 00:03:55,900 --> 00:03:59,467 THE SUN WARMS THE LAND, GENERATING WIND. 80 00:03:59,467 --> 00:04:04,800 IT CAUSES THE SEAS TO EVAPORATE, CREATING CLOUDS AND RAIN. 81 00:04:07,400 --> 00:04:11,233 SATURN LIES TOO FAR FROM THE SUN TO FEEL THE SAME WARMTH, 82 00:04:11,233 --> 00:04:13,333 SO THE HEAT THAT DRIVES ITS WEATHER 83 00:04:13,333 --> 00:04:17,333 MUST BE COMING FROM SOMEWHERE ELSE. 84 00:04:17,333 --> 00:04:19,900 TO UNDERSTAND THIS MYSTERIOUS HEAT SOURCE, 85 00:04:19,900 --> 00:04:23,333 WE NEED TO GO BACK 4 1/2 BILLION YEARS... 86 00:04:24,633 --> 00:04:27,433 TO THE BIRTH OF THE RINGED PLANET. 87 00:04:30,500 --> 00:04:32,067 [ WATER STREAMING ] 88 00:04:32,067 --> 00:04:34,333 THE PLANETS IN OUR SOLAR SYSTEM 89 00:04:34,333 --> 00:04:37,133 EMERGED FROM A VAST, SWIRLING CLOUD 90 00:04:37,133 --> 00:04:40,233 OF ICE, DUST, AND GAS. 91 00:04:42,167 --> 00:04:45,833 THE SAME INGREDIENTS CAN STILL BE FOUND ON EARTH TODAY 92 00:04:45,833 --> 00:04:47,600 IN PLACES LIKE ICELAND, 93 00:04:47,600 --> 00:04:51,633 WHERE VOLCANIC ASH MIXES WITH ICY GLACIERS. 94 00:04:51,633 --> 00:04:54,800 IF YOU WANNA BUILD A GIANT PLANET LIKE SATURN, 95 00:04:54,800 --> 00:04:59,067 THIS PILE OF RAW MATERIAL HERE IS A GREAT VISUAL ANALOG. 96 00:04:59,067 --> 00:05:01,400 THERE'S A LOT OF OXYGEN AND HYDROGEN IN THE UNIVERSE. 97 00:05:01,400 --> 00:05:03,667 THAT MAKES WATER, AND THAT MAKES WATER ICE, 98 00:05:03,667 --> 00:05:05,800 AND THE STUFF INITIALLY THAT MADE THE SOLAR SYSTEM 99 00:05:05,800 --> 00:05:07,300 IS BASICALLY THIS STUFF HERE. 100 00:05:07,300 --> 00:05:09,867 IT'S DIRTY ICE, WATER ICE, WITH A LITTLE BIT OF -- 101 00:05:09,867 --> 00:05:12,333 LITTLE BIT OF ROCKY AND METALLIC MINERALS LEFT IN THERE 102 00:05:12,333 --> 00:05:14,200 OUT THERE IN THE COLD OF SPACE. 103 00:05:17,633 --> 00:05:19,633 Narrator: 4 1/2 BILLION YEARS AGO, 104 00:05:19,633 --> 00:05:22,333 A VAST CLOUD OF DIRTY ICE PARTICLES 105 00:05:22,333 --> 00:05:27,333 SHROUDED IN HYDROGEN AND HELIUM COLLAPSES UNDER ITS OWN GRAVITY, 106 00:05:27,333 --> 00:05:31,300 AND AT THE CENTER, A NEW STAR -- OUR SUN -- 107 00:05:31,300 --> 00:05:33,500 SPARKS INTO LIFE. 108 00:05:34,767 --> 00:05:38,200 THE HEAT OF THE NEW STAR MELTS THE ICE CLOSEST TO IT 109 00:05:38,200 --> 00:05:42,567 AND BLOWS AWAY THE GAS, LEAVING ONLY ROCKY DEBRIS BEHIND. 110 00:05:42,567 --> 00:05:47,433 BUT FARTHER OUT, ICY MATERIAL AND GAS SURVIVE. 111 00:05:47,433 --> 00:05:50,733 A BOUNDARY FORMS -- A FROST LINE 112 00:05:50,733 --> 00:05:55,767 BETWEEN THE ROCKY INNER CLOUD AND THE ICY GAS BEYOND. 113 00:05:56,900 --> 00:05:59,533 ONCE YOU FIRE UP THAT CAMPFIRE, IF YOU WILL, 114 00:05:59,533 --> 00:06:01,100 WHAT WOULD BE LEFT BEHIND IN THE INNER SOLAR SYSTEM 115 00:06:01,100 --> 00:06:02,500 IS GONNA BE THIS STUFF -- 116 00:06:02,500 --> 00:06:04,600 SILICATE MINERALS YOU MAKE A PLANET LIKE THE EARTH FROM. 117 00:06:04,600 --> 00:06:07,833 BUT FAR AWAY FROM THE SUN, WHERE IT'S COLDER, 118 00:06:07,833 --> 00:06:11,100 YOU CROSS THE FROST LINE, AND WHAT'S OUT THERE 119 00:06:11,100 --> 00:06:14,967 IS STILL COLD ENOUGH TO MAINTAIN THE ICE BEHIND, 120 00:06:14,967 --> 00:06:17,333 AND THERE'S A LOT OF IT THERE. 121 00:06:17,333 --> 00:06:20,333 AT FIRST YOU MAKE SORT OF A SOLID CORE OF THIS MATERIAL, 122 00:06:20,333 --> 00:06:21,500 BUT WHEN YOU REACH A CRITICAL MASS, 123 00:06:21,500 --> 00:06:23,533 YOU'VE GOT ENOUGH GRAVITATIONAL INFLUENCE 124 00:06:23,533 --> 00:06:26,200 TO START TO DIRECTLY DRAW IN SOME OF THE HYDROGEN AND HELIUM 125 00:06:26,200 --> 00:06:28,500 IN THE INTERPLANETARY CLOUD. 126 00:06:29,800 --> 00:06:32,633 Narrator: SATURN'S HUGE SOLID CORE, 127 00:06:32,633 --> 00:06:35,833 NOW 10 TO 20 TIMES THE SIZE OF THE EARTH, 128 00:06:35,833 --> 00:06:40,367 GENERATES RELENTLESS GRAVITY AND DRAWS IN GAS. 129 00:06:40,367 --> 00:06:46,867 THE BIGGER THIS GAS BALL GETS, THE MORE MATERIAL IT SUCKS IN. 130 00:06:46,867 --> 00:06:49,500 SATURN'S MASSIVE GRAVITY THEN GETS TO WORK 131 00:06:49,500 --> 00:06:53,500 ON ITS FLEDGLING ATMOSPHERE, COMPRESSING IT. 132 00:06:53,500 --> 00:06:57,533 AND LIKE ANY GAS UNDER PRESSURE, IT GETS HOT -- 133 00:06:57,533 --> 00:06:59,667 SERIOUSLY HOT. 134 00:07:00,967 --> 00:07:04,067 EVEN TODAY, SATURN'S HIGH PRESSURE ATMOSPHERE 135 00:07:04,067 --> 00:07:07,467 HEATS ITS CORE TO 21,000 DEGREES -- 136 00:07:07,467 --> 00:07:11,267 TWICE THE TEMPERATURE OF THE SURFACE OF THE SUN. 137 00:07:13,467 --> 00:07:15,533 AND IT'S THIS HEAT RISING UP 138 00:07:15,533 --> 00:07:18,300 WHICH FORMS SATURN'S DISTINCT BANDS 139 00:07:18,300 --> 00:07:22,233 AND DRIVES ITS EXTREME WEATHER. 140 00:07:22,233 --> 00:07:24,533 Thaller: SATURN'S ACTUALLY ROTATING VERY QUICKLY. 141 00:07:24,533 --> 00:07:25,833 IT'S A LARGE PLANET. 142 00:07:25,833 --> 00:07:28,433 IT ROTATES ONCE ON ITS AXIS ABOUT EVERY 10 HOURS. 143 00:07:28,433 --> 00:07:31,067 SO AS THE WEATHER COMES U9P FROM THE INTERIOR, 144 00:07:31,067 --> 00:07:33,167 IT GETS SMEARED OUT INTO BANDS. 145 00:07:35,933 --> 00:07:37,967 Narrator: THAT'S SATURN'S NORTH POLE. 146 00:07:37,967 --> 00:07:40,833 THE BANDS DO SOMETHING THAT AT FIRST GLANCE, 147 00:07:40,833 --> 00:07:42,933 SEEMS IMPOSSIBLE. 148 00:07:42,933 --> 00:07:46,067 Plait: THERE IS A GIGANTIC VORTEX -- 149 00:07:46,067 --> 00:07:47,767 A SPINNING REGION OF AIR 150 00:07:47,767 --> 00:07:50,333 THAT'S SHAPED LIKE A PERFECT HEXAGON. 151 00:07:50,333 --> 00:07:51,933 Thaller: YOU HAVE WAVES 152 00:07:51,933 --> 00:07:53,433 OF PRESSURE, DENSITY, AND TEMPERATURE 153 00:07:53,433 --> 00:07:55,700 THAT START TO INTERACT WITH EACH OTHER. 154 00:07:55,700 --> 00:07:57,900 AND THESE WAVES CAN ACTUALLY INTERFERE 155 00:07:57,900 --> 00:07:59,200 AND BECOME ONE BIG WAVE 156 00:07:59,200 --> 00:08:01,533 THAT GOES ALL THE WAY AROUND THE PLANET. 157 00:08:01,533 --> 00:08:03,267 Narrator: THIS GIANT WAVE SETTLES 158 00:08:03,267 --> 00:08:06,867 INTO A LONG-LASTING PATTERN, BECAUSE BELOW, 159 00:08:06,867 --> 00:08:08,500 THERE'S NO ROCKY SURFACE 160 00:08:08,500 --> 00:08:10,967 TO DISRUPT THE WINDS THAT FORM IT. 161 00:08:10,967 --> 00:08:14,133 Thaller: THEY FORM A BEAUTIFULLY DEFINED REGULAR HEXAGON. 162 00:08:14,133 --> 00:08:16,467 IT'S ONE OF THE MOST SPECTACULAR THINGS ABOUT SATURN. 163 00:08:19,733 --> 00:08:21,933 Narrator: IT TOOK ROBOTIC PROBES 164 00:08:21,933 --> 00:08:24,533 TO REVEAL THE WEIRD WEATHER ON SATURN, 165 00:08:24,533 --> 00:08:27,367 BUT IF THESE CLOSE-UP SHOTS OF STORMS AND LIGHTNING 166 00:08:27,367 --> 00:08:29,700 TOOK SCIENTISTS BY SURPRISE, 167 00:08:29,700 --> 00:08:34,367 THEY WERE NOTHING COMPARED TO THE SHOCK OF WHAT CAME NEXT, 168 00:08:34,367 --> 00:08:37,433 BECAUSE THE RINGS ARE ALIVE. 169 00:08:50,200 --> 00:08:52,900 Narrator: IMAGINE SATURN WITHOUT ITS RINGS -- 170 00:08:52,900 --> 00:08:58,167 JUST A PALE GLOBE FLOATING IN THE DARKNESS OF SPACE. 171 00:09:00,633 --> 00:09:03,833 WITH RINGS, IT'S MAGICAL. 172 00:09:07,733 --> 00:09:09,067 Krauss: UNDOUBTEDLY, THE ONE THING 173 00:09:09,067 --> 00:09:11,367 THAT CAPTURES EVERYONE ABOUT SATURN IS THE RINGS. 174 00:09:11,367 --> 00:09:14,433 IT'S INSPIRED FICTION STORIES, AND IT'S INSPIRED EVERYONE 175 00:09:14,433 --> 00:09:16,500 WHO'S LOOKED AT IT IN THE NIGHT SKY. 176 00:09:16,500 --> 00:09:19,233 Plait: WHEN I WAS 4 OR 5 YEARS OLD, 177 00:09:19,233 --> 00:09:21,767 MY PARENTS BOUGHT A SMALL DEPARTMENT STORE TELESCOPE, 178 00:09:21,767 --> 00:09:24,433 AND I REMEMBER LOOKING DOWN INTO THAT EYEPIECE 179 00:09:24,433 --> 00:09:29,133 AND SEEING THIS PERFECT JEWEL OF A PLANET. 180 00:09:29,133 --> 00:09:31,133 THERE'S JUST NOTHING BETTER THAN THIS, 181 00:09:31,133 --> 00:09:32,300 AND YOU CAN JUST SEE THE RINGS 182 00:09:32,300 --> 00:09:34,167 GOING AROUND THE PLANET JUST PERFECTLY. 183 00:09:34,167 --> 00:09:37,767 THEY'RE JUST A GORGEOUS ELLIPTICAL RACE TRACK. 184 00:09:37,767 --> 00:09:41,333 Narrator: FROM THE EYEPIECE OF A SMALL TELESCOPE, 185 00:09:41,333 --> 00:09:45,167 THE RINGS SEEM QUIET AND SERENE. 186 00:09:45,167 --> 00:09:48,933 BUT UP CLOSE, IT'S A VERY DIFFERENT PICTURE. 187 00:09:48,933 --> 00:09:53,233 WE KNOW THIS THANKS TO A SPACE PROBE CALLED CASSINI, 188 00:09:53,233 --> 00:09:56,600 AND OVER 10 YEARS OF IMAGES LIKE THESE. 189 00:09:59,867 --> 00:10:03,700 ICE PARTICLES JOSTLE FOR POSITION LIKE STOCK CARS, 190 00:10:03,700 --> 00:10:05,167 TRAVELING INSIDE THE RINGS 191 00:10:05,167 --> 00:10:09,300 AT HUNDREDS OF THOUSANDS OF MILES AN HOUR. 192 00:10:09,300 --> 00:10:12,033 THESE PARTICLES RANGE IN SIZE FROM CHUNKS OF ICE 193 00:10:12,033 --> 00:10:17,467 AS BIG AS HOUSES TO THE FINEST POWDER SNOW. 194 00:10:17,467 --> 00:10:19,300 IT WASN'T UNTIL WE WENT TO SATURN 195 00:10:19,300 --> 00:10:21,533 AND STAYED THERE WITH CASSINI THAT WE LEARNED 196 00:10:21,533 --> 00:10:24,200 JUST HOW FIERCELY COMPLEX IT IS. 197 00:10:24,200 --> 00:10:26,233 YOU HAVE THE GRAVITY OF THE PLANET ITSELF 198 00:10:26,233 --> 00:10:27,633 AND ALL OF THESE MOONS 199 00:10:27,633 --> 00:10:30,533 INTERACTING WITH THE RINGS AND THE MOONS AND THE PLANET. 200 00:10:30,533 --> 00:10:34,167 ALL OF THESE THINGS ARE SCULPTING THAT ENTIRE SYSTEM 201 00:10:34,167 --> 00:10:37,100 ON SCALES THAT ARE BOTH SUBTLE AND GROSS, 202 00:10:37,100 --> 00:10:41,833 AND IT MAKES THIS MAGNIFICENT CROWN JEWEL OF THE SOLAR SYSTEM. 203 00:10:43,033 --> 00:10:45,233 Thaller: AS SMALL MOONS GO AROUND AND SIDE, 204 00:10:45,233 --> 00:10:48,200 THE RING PARTICLES DANCE AROUND THEM IN RESPONSE. 205 00:10:48,200 --> 00:10:50,733 WE SEE AREAS OF THE RINGS THAT GET RAISED UP 206 00:10:50,733 --> 00:10:51,933 AS THE MOON GOES BY. 207 00:10:51,933 --> 00:10:54,600 MOONS WILL EVEN SWITCH ORBITS WITH EACH OTHER, 208 00:10:54,600 --> 00:10:55,967 SO THERE'S A LOT OF DYNAMIC STUFF 209 00:10:55,967 --> 00:10:58,233 GOING ON INSIDE THE RINGS. 210 00:10:59,233 --> 00:11:01,300 Narrator: SCIENTISTS BELIEVE THAT FROM TIME TO TIME, 211 00:11:01,300 --> 00:11:04,633 SATURN'S ICY MOONS BREAK UP, 212 00:11:04,633 --> 00:11:07,067 ADDING NEW MATERIAL TO THE RINGS. 213 00:11:07,067 --> 00:11:08,800 [ EXPLOSION ] 214 00:11:08,800 --> 00:11:11,600 THIS MEANS THAT THE STRUCTURE OF THE RINGS 215 00:11:11,600 --> 00:11:15,100 IS CONSTANTLY EVOLVING. 216 00:11:15,100 --> 00:11:17,900 WITH CASSINI, SCIENTISTS CAN DECONSTRUCT THE PHYSICS 217 00:11:17,900 --> 00:11:21,400 OF THIS EVOLUTION, AND IT'S TEACHING US THE RULES 218 00:11:21,400 --> 00:11:24,400 THAT MAKE THE WHOLE UNIVERSE TICK. 219 00:11:28,267 --> 00:11:30,200 ALL THE PLANETS IN OUR SOLAR SYSTEM 220 00:11:30,200 --> 00:11:34,067 EVOLVE FROM THE SAME FLAT DISC OF DUST AND GAS 221 00:11:34,067 --> 00:11:37,700 4 1/2 BILLION YEARS AGO. 222 00:11:37,700 --> 00:11:42,333 ASTRONOMERS SEE SIMILAR DISCS AROUND YOUNG DISTANT STARS. 223 00:11:42,333 --> 00:11:44,733 BUT EVEN WITH OUR MOST POWERFUL TELESCOPES, 224 00:11:44,733 --> 00:11:48,667 WE CAN'T SEE PLANETS FORMING. THEY'RE TOO FAR AWAY. 225 00:11:48,667 --> 00:11:51,967 BUT SATURN'S RINGS ARE RIGHT ON OUR DOORSTEP, 226 00:11:51,967 --> 00:11:55,567 A VERITABLE SNAPSHOT OF A MINI SOLAR SYSTEM 227 00:11:55,567 --> 00:11:59,600 CAUGHT IN THE PROCESS OF FORMATION. 228 00:11:59,600 --> 00:12:00,967 Porco: LOOKING AT THE RINGS, 229 00:12:00,967 --> 00:12:05,133 WE'RE LOOKING AT THE FORMATION OF PLANETS OR BODIES 230 00:12:05,133 --> 00:12:07,567 IN AN ARRESTED STATE OF DEVELOPMENT. 231 00:12:07,567 --> 00:12:09,533 IT'S LIKE YOU TOOK THE BEGINNING STAGES 232 00:12:09,533 --> 00:12:12,400 OF THE FORMATION OF THE PLANETS BUT STOPPED IT. 233 00:12:12,400 --> 00:12:15,567 [ EXPLOSION ] 234 00:12:15,567 --> 00:12:19,333 Narrator: CASSINI SHOWS STRUCTURES FORMING SPONTANEOUSLY 235 00:12:19,333 --> 00:12:21,433 INSIDE THE RINGS. 236 00:12:21,433 --> 00:12:23,267 Porco: THEY DON'T EVEN NEED TO BE TICKLED. 237 00:12:23,267 --> 00:12:27,233 THEY DON'T NEED TO BE DISTURBED INTO FORMING STRUCTURES. 238 00:12:27,233 --> 00:12:29,600 THEY FORM THEM ON THEIR OWN. 239 00:12:29,600 --> 00:12:30,900 Narrator: DOES THIS TINY MOON, 240 00:12:30,900 --> 00:12:33,500 CAPTURED IN THE PROCESS OF FORMATION, 241 00:12:33,500 --> 00:12:36,100 SHOW US HOW THE EARTH STARTED ITS LIFE? 242 00:12:36,100 --> 00:12:41,067 Porco: YOU GET SOMETHING THAT JUST HAPPENS TO FORM 243 00:12:41,067 --> 00:12:44,633 OUT OF RANDOM PROCESSES, AND THAT MIMICS WHAT ASTRONOMERS 244 00:12:44,633 --> 00:12:48,133 THINK THEY'RE SEEING IN PROTOPLANETARY DISCS 245 00:12:48,133 --> 00:12:52,567 SURROUNDING OTHER STARS IN THE COSMOS AROUND US. 246 00:12:52,567 --> 00:12:57,233 Narrator: CASSINI SEES CURIOUS PROPELLER-LIKE STRUCTURES 247 00:12:57,233 --> 00:13:00,433 INSIDE SATURN'S BROAD A RING. 248 00:13:00,433 --> 00:13:05,600 THEY'RE CAUSED BY RING PARTICLES WASHING OVER TINY HIDDEN MOONS. 249 00:13:07,533 --> 00:13:09,933 THE PARTICLES COLLIDE WITH THE MOONS, 250 00:13:09,933 --> 00:13:13,200 SENDING THEM INTO RANDOM, EVER-CHANGING ORBITS, 251 00:13:13,200 --> 00:13:16,733 SOMETIMES CLOSER TO SATURN AND SOMETIMES FARTHER AWAY. 252 00:13:20,900 --> 00:13:24,067 PERHAPS SIMILAR FORCES INFLUENCED THE EARTH'S FORMATION 253 00:13:24,067 --> 00:13:25,600 AROUND THE SUN, 254 00:13:25,600 --> 00:13:29,400 PUSHING IT INTO CLOSER OR WIDER ORBITS. 255 00:13:33,900 --> 00:13:36,200 SATURN'S RINGS ALSO HELP US UNDERSTAND 256 00:13:36,200 --> 00:13:39,667 WHY PLANETS STOP GROWING. 257 00:13:39,667 --> 00:13:41,900 A WALNUT-SHAPED MOON CALLED "PAN" 258 00:13:41,900 --> 00:13:45,933 SITS NEAR THE MIDDLE OF SATURN'S A RING. 259 00:13:45,933 --> 00:13:49,667 WITH SO MUCH ICE AROUND IT TO GOBBLE UP, 260 00:13:49,667 --> 00:13:53,067 PAN SHOULD BE HUGE, BUT IT'S TINY, 261 00:13:53,067 --> 00:13:55,467 ONLY 20 MILES IN DIAMETER. 262 00:13:55,467 --> 00:13:58,400 IF YOU HAVE A MOON EMBEDDED IN A DISC OF RING PARTICLES, 263 00:13:58,400 --> 00:14:01,467 YOU MIGHT NAIVELY THINK IT JUST SECRETES RING PARTICLES 264 00:14:01,467 --> 00:14:04,867 UNTIL IT GROWS INTO A, YOU KNOW, A BIGGER MOON. 265 00:14:04,867 --> 00:14:08,200 BUT ACTUALLY WE FIND MOONS CREATE GAPS 266 00:14:08,200 --> 00:14:09,567 IN THE RING AROUND THEM. 267 00:14:09,567 --> 00:14:11,533 SO PAN HAS CREATED THE INKY GAP. 268 00:14:11,533 --> 00:14:13,833 DAPHNIS HAS CREATED THE KEELER GAP. 269 00:14:15,300 --> 00:14:18,400 Narrator: RATHER THAN PULLING RING MATERIAL IN, 270 00:14:18,400 --> 00:14:21,400 PAN APPEARS TO PUSH IT AWAY. 271 00:14:21,400 --> 00:14:22,733 AS THE MOON PASSES 272 00:14:22,733 --> 00:14:25,200 THE SLOWER MOVING MATERIAL OUTSIDE IT, 273 00:14:25,200 --> 00:14:28,100 PAN'S GRAVITY FLINGS THE PARTICLES OUT 274 00:14:28,100 --> 00:14:30,633 INTO WIDER ORBITS. 275 00:14:30,633 --> 00:14:34,167 THE FASTER MATERIAL INSIDE PAN'S ORBIT IS SLOW. 276 00:14:34,167 --> 00:14:37,100 AS IT PASSES, THE LITTLE MOON, CAUSING IT TO FALL AWAY 277 00:14:37,100 --> 00:14:38,767 TOWARDS SATURN. 278 00:14:38,767 --> 00:14:43,800 THIS NATURAL CUTOFF AND GROWTH MIGHT EXPLAIN WHY 279 00:14:43,800 --> 00:14:46,267 MULTIPLE PLANETS FORM AROUND STARS, 280 00:14:46,267 --> 00:14:51,100 INSTEAD OF SINGLE GIANT PLANETS THAT EAT THE WHOLE BUFFET. 281 00:14:51,100 --> 00:14:54,733 OF ALL CASSINI'S DISCOVERIES, 282 00:14:54,733 --> 00:14:59,100 THE MOST IMPORTANT IS ALSO THE MOST SURPRISING -- 283 00:14:59,100 --> 00:15:04,733 A TINY ICE MOON THAT MAY BE HOME TO LIFE. 284 00:15:17,900 --> 00:15:19,133 Narrator: FOR MOST OF HISTORY, 285 00:15:19,133 --> 00:15:22,167 THE ONLY MOON WE'VE BEEN ABLE TO STUDY UP CLOSE 286 00:15:22,167 --> 00:15:24,567 IS OUR OWN. 287 00:15:24,567 --> 00:15:30,233 MULTIPLE DEEP CRATERS TELL A POWERFUL STORY. 288 00:15:30,233 --> 00:15:32,100 OUR MOON IS DEAD. 289 00:15:32,100 --> 00:15:34,067 THERE'S NO ACTIVE GEOLOGY OR WEATHER 290 00:15:34,067 --> 00:15:36,767 TO WIPE AWAY THESE ANCIENT SCARS. 291 00:15:36,767 --> 00:15:41,300 BUT WHAT ABOUT THE MOONS AROUND OTHER PLANETS LIKE SATURN? 292 00:15:41,300 --> 00:15:43,933 ARE THEY DEAD, TOO? 293 00:15:43,933 --> 00:15:45,367 Thaller: OUR FIRST ASSUMPTION ABOUT SATURN 294 00:15:45,367 --> 00:15:46,933 WAS THAT THE MOONS WOULD BE LIKE THAT -- 295 00:15:46,933 --> 00:15:50,433 COLD, DEAD, LIFELESS RELICS FROM THE EARLY SOLAR SYSTEM. 296 00:15:50,433 --> 00:15:52,733 IT WASN'T UNTIL WE INVENTED SPACECRAFT 297 00:15:52,733 --> 00:15:56,067 THAT COULD GO TO THESE MOONS THAT WE DISCOVERED 298 00:15:56,067 --> 00:15:59,900 HOW INCREDIBLY DIVERSE OUR SOLAR SYSTEM TRULY IS. 299 00:16:05,333 --> 00:16:07,200 Narrator: TAKE ENCELADUS -- 300 00:16:07,200 --> 00:16:12,100 AN ICE MOON BARELY 300 MILES ACROSS. 301 00:16:12,100 --> 00:16:17,167 NOBODY PAID IT ANY ATTENTION A DECADE AGO. 302 00:16:17,167 --> 00:16:21,567 BUT TODAY, IT'S A GEOLOGICAL ROCK STAR. 303 00:16:21,567 --> 00:16:23,967 AND THIS IS WHY. 304 00:16:23,967 --> 00:16:28,067 ENCELADUS ORBITS INSIDE SATURN'S OUTER MOST RING -- 305 00:16:28,067 --> 00:16:30,567 THE E RING. 306 00:16:30,567 --> 00:16:34,133 THE E RING PUZZLED SCIENTISTS BECAUSE THEY COULDN'T FIGURE OUT 307 00:16:34,133 --> 00:16:36,733 HOW A RING SO BROAD AND SO DIFFUSE 308 00:16:36,733 --> 00:16:39,067 COULD HOLD ITSELF TOGETHER. 309 00:16:41,167 --> 00:16:45,633 THE CASSINI TEAM DECIDED TO TAKE A CLOSE FLYBY OF ENCELADUS 310 00:16:45,633 --> 00:16:49,300 TO SOLVE THE MYSTERY. 311 00:16:49,300 --> 00:16:50,433 Thaller: DID IT HAVE SOMETHING TO DO 312 00:16:50,433 --> 00:16:52,633 WITH KEEPING THE PARTICLES TOGETHER? 313 00:16:52,633 --> 00:16:56,667 WHAT WAS THE CONNECTION BETWEEN THE E RING AND ENCELADUS? 314 00:16:56,667 --> 00:16:59,800 WELL, NOW WE KNOW THAT ENCELADUS IS ACTUALLY RESPONSIBLE 315 00:16:59,800 --> 00:17:02,067 FOR THE E RING BEING THERE IN THE FIRST PLACE. 316 00:17:04,933 --> 00:17:06,800 Narrator: 2005 -- 317 00:17:06,800 --> 00:17:10,367 CASSINI CAPTURES AN ASTONISHING SIGHT -- 318 00:17:10,367 --> 00:17:15,067 A HUNDRED GEYSERS SHOOTING ICE PARTICLES MILES INTO SPACE 319 00:17:15,067 --> 00:17:17,800 FROM CRACKS IN THE SOUTH POLE. 320 00:17:17,800 --> 00:17:23,100 ENCELADUS IS HURDLING ITS GUTS INTO SPACE AT A COLOSSAL RATE. 321 00:17:23,100 --> 00:17:25,067 AS ENCELADUS ORBITS SATURN, 322 00:17:25,067 --> 00:17:28,800 THESE ICY PLUMES FEED A VAST SHIMMERING HALO 323 00:17:28,800 --> 00:17:30,367 AROUND THE PLANET -- 324 00:17:30,367 --> 00:17:34,900 THE MYSTERIOUS E RING. 325 00:17:37,633 --> 00:17:41,433 THIS ICY PLUME ALSO INTERACTS WITH SATURN'S MAGNETIC FIELD, 326 00:17:41,433 --> 00:17:45,233 CAUSING A PLASMA CLOUD OF CHARGED PARTICLES. 327 00:17:48,433 --> 00:17:52,067 THE PARTICLES RACE ALONG SATURN'S MAGNETIC FIELD LINES 328 00:17:52,067 --> 00:17:54,767 AND SLAM INTO SATURN'S POLAR ATMOSPHERE, 329 00:17:54,767 --> 00:17:59,800 RAISING HUGE ULTRAVIOLET AURORAS. 330 00:17:59,800 --> 00:18:04,067 GEYSERS EXPLAIN THE E RING, 331 00:18:04,067 --> 00:18:07,267 BUT HOW CAN THEY EXIST ON A FROZEN MOON 332 00:18:07,267 --> 00:18:10,300 A BILLION MILES FROM THE SUN? 333 00:18:13,567 --> 00:18:17,500 ON EARTH, GEYSERS FORM IN HIGHLY VOLCANIC PLACES 334 00:18:17,500 --> 00:18:21,533 WHERE WATER COMES INTO CONTACT WITH HOT ROCKS. 335 00:18:21,533 --> 00:18:25,700 ENCELADUS, SO SMALL, AND SO FAR FROM THE SUN, 336 00:18:25,700 --> 00:18:28,367 SHOULD BE COLD AND DEAD. 337 00:18:28,367 --> 00:18:32,400 BUT THANKS TO SATURN'S GRAVITY, IT'S NOT. 338 00:18:35,767 --> 00:18:37,900 THE SOURCE OF THE HEATING ON ENCELADUS 339 00:18:37,900 --> 00:18:41,067 IS THE ECCENTRIC ORBIT OF THAT MOON. 340 00:18:41,067 --> 00:18:43,067 SOMETIMES IT'S A LITTLE CLOSER TO SATURN, 341 00:18:43,067 --> 00:18:45,067 SOMETIMES IT'S A LITTLE FURTHER AWAY. 342 00:18:45,067 --> 00:18:47,667 AND THAT HEATING ON ENCELADUS FROM THAT KNEADING 343 00:18:47,667 --> 00:18:51,267 GRAVITATIONALLY MAKING THE MOON STRETCH AND PULL 344 00:18:51,267 --> 00:18:52,700 IS WHAT WARMS THE INTERIOR, 345 00:18:52,700 --> 00:18:55,633 CAUSING THE ACTIVITY ON ENCELADUS THAT WE SEE TODAY. 346 00:18:59,367 --> 00:19:01,667 Narrator: THE GRAVITATIONAL PULL OF SATURN 347 00:19:01,667 --> 00:19:06,333 REACHES DEEP INTO ENCELADUS BEYOND ITS WATER-ICE EXTERIOR 348 00:19:06,333 --> 00:19:08,933 GRIPPING ITS ROCKY CORE. 349 00:19:11,600 --> 00:19:14,733 AS SATURN'S GRASP STRENGTHENS AND WEAKENS, 350 00:19:14,733 --> 00:19:17,633 IT MASSAGES THIS COLD, ROCKY HEART, 351 00:19:17,633 --> 00:19:22,733 BRINGING IT TO GEOLOGICAL LIFE WITH FRICTIONAL HEAT. 352 00:19:22,733 --> 00:19:25,067 THE HEAT MELTS THE ICE AROUND IT, 353 00:19:25,067 --> 00:19:26,867 CREATING A VAST SUBSURFACE LAKE 354 00:19:26,867 --> 00:19:29,333 AT THE SOUTHERN POLE OF ENCELADUS. 355 00:19:29,333 --> 00:19:35,433 THIS WATER JETS OUT THROUGH HUGE CRACKS IN THE SURFACE ICE. 356 00:19:35,433 --> 00:19:37,767 ON EARTH, WHERE THERE'S LIQUID WATER, 357 00:19:37,767 --> 00:19:39,267 THERE'S LIFE. 358 00:19:39,267 --> 00:19:41,833 COULD ENCELADUS HAVE WHAT IT TAKES 359 00:19:41,833 --> 00:19:45,600 FOR SIMPLE ORGANISMS TO EXIST? 360 00:19:45,600 --> 00:19:48,400 ONCE CASSINI SAW THESE GEYSERS, THE SCIENTISTS KNEW 361 00:19:48,400 --> 00:19:51,200 THEY HAD FOUND SOMETHING EXTREMELY WONDERFUL. 362 00:19:51,200 --> 00:19:54,200 THEY ACTUALLY CHANGED THE MISSION OF CASSINI ITSELF, 363 00:19:54,200 --> 00:19:55,800 CHANGED ITS TRAJECTORY. 364 00:19:55,800 --> 00:19:59,067 WE SENT THE CASSINI SPACECRAFT TO FLY VERY, VERY CLOSE 365 00:19:59,067 --> 00:20:03,500 OVER THESE CRACKS WHERE THE WATER WAS RUSHING OUT. 366 00:20:03,500 --> 00:20:05,800 Narrator: SCIENTISTS CLUNG TO THE FAINT HOPE 367 00:20:05,800 --> 00:20:09,567 THAT THE WATER WOULD CONTAIN SALTS AND ORGANIC MOLECULES 368 00:20:09,567 --> 00:20:10,867 LIKE AMMONIA, 369 00:20:10,867 --> 00:20:15,200 THE BUILDING BLOCKS OF LIFE HERE ON EARTH. 370 00:20:15,200 --> 00:20:21,767 STUNNINGLY, CASSINI'S CENSORS TASTED ALL OF THEM IN ABUNDANCE. 371 00:20:21,767 --> 00:20:24,600 McKay: IN THAT PLUME, THERE'S ORGANIC MATERIAL. 372 00:20:24,600 --> 00:20:27,667 IT'S NOT WATER. IT'S A SOUP. 373 00:20:27,667 --> 00:20:29,167 THAT'S INCREDIBLE. 374 00:20:29,167 --> 00:20:31,433 ALL THE MAIN REQUIREMENTS FOR HABITABILITY, 375 00:20:31,433 --> 00:20:35,333 ENERGY SOURCE, LIQUID WATER, SOURCE OF BIOLOGICAL NITROGEN 376 00:20:35,333 --> 00:20:37,700 AND AMMONIA, ORGANIC MATERIAL, 377 00:20:37,700 --> 00:20:40,033 AND THE SAMPLES ARE COMING UP INTO SPACE. 378 00:20:40,033 --> 00:20:42,333 THERE'S A BIG SIGN -- FREE SAMPLES, TAKE ONE. 379 00:20:42,333 --> 00:20:44,600 THERE COULD BE LIFE THAT COULD'VE EVOLVED THERE. 380 00:20:44,600 --> 00:20:46,833 NOW WE DON'T KNOW. WE HAVEN'T SEEN IT. 381 00:20:46,833 --> 00:20:51,267 BUT THE CONDITIONS THERE ARE AS GOOD THERE NOW 382 00:20:51,267 --> 00:20:53,600 AS THEY WERE ON EARTH 3 BILLION YEARS AGO 383 00:20:53,600 --> 00:20:55,267 WHEN LIFE AROSE HERE. 384 00:20:55,267 --> 00:20:59,033 Narrator: THE SENSATIONAL REALIZATION THAT ENCELADUS 385 00:20:59,033 --> 00:21:02,267 MAY HARBOR LIFE HAS SPARKED INTENSE DEBATE 386 00:21:02,267 --> 00:21:04,700 ABOUT FUTURE MISSIONS TO FIND IT, 387 00:21:04,700 --> 00:21:09,333 BECAUSE IT HAS A RIVAL FOR THOSE PRECIOUS RESEARCH DOLLARS. 388 00:21:09,333 --> 00:21:14,133 SATURN'S LARGEST MOON, TITAN, COULD ALSO BE HOME TO LIFE -- 389 00:21:14,133 --> 00:21:16,333 BIZARRE LIFE. 390 00:21:16,333 --> 00:21:18,767 AND WE MAY HAVE ALREADY FOUND IT. 391 00:21:31,400 --> 00:21:34,800 Narrator: MORE THAN 60 MOONS ORBIT THE PLANET SATURN, 392 00:21:34,800 --> 00:21:38,567 BUT ONE DWARFS THEM ALL. 393 00:21:38,567 --> 00:21:43,133 TITAN IS A COLOSSUS, BIGGER THAN THE PLANET MERCURY. 394 00:21:43,133 --> 00:21:47,967 A THICK ORANGE HAZE HIDES ITS SURFACE FROM OUR TELESCOPES, 395 00:21:47,967 --> 00:21:51,100 AND WHEN THE CASSINI MISSION FIRST APPEARED BENEATH 396 00:21:51,100 --> 00:21:55,067 TITAN'S ORANGE CLOAK, IT REVEALED A WORLD WEIRDER 397 00:21:55,067 --> 00:21:57,533 THAN WE COULD EVER HAVE IMAGINED. 398 00:21:57,533 --> 00:22:00,100 TITAN IS AN AMAZING PLACE. 399 00:22:00,100 --> 00:22:02,233 AND OF ALL THE THINGS GOING ON AROUND SATURN, 400 00:22:02,233 --> 00:22:05,833 TITAN MIGHT BE THE MOST EXCITING OF ALL. 401 00:22:08,067 --> 00:22:11,833 Narrator: TITAN HAS MOUNTAINS AND DESERTS, RIVERS AND LAKES. 402 00:22:11,833 --> 00:22:17,167 ONLY THE EARTH CAN MATCH IT FOR GEOLOGICAL DIVERSITY. 403 00:22:17,167 --> 00:22:21,067 BUT HERE, WATER ICE TAKES THE PLACE OF BEDROCK, 404 00:22:21,067 --> 00:22:24,100 FROZEN AT 300 DEGREES BELOW ZERO. 405 00:22:24,100 --> 00:22:26,167 AND INSTEAD OF WATER, 406 00:22:26,167 --> 00:22:29,833 THE RIVERS ON TITAN FLOW WITH METHANE. 407 00:22:29,833 --> 00:22:31,567 Thaller: THIS IS A PLACE 408 00:22:31,567 --> 00:22:34,400 WHERE IT ACTUALLY RAINS LIQUID METHANE, 409 00:22:34,400 --> 00:22:36,067 LIQUID NATURAL GAS. 410 00:22:36,067 --> 00:22:39,933 THIS LIQUID IS FILLING UP RIVERS AND LAKES. 411 00:22:39,933 --> 00:22:42,333 Plait: THIS MAKES TITAN INCREDIBLY SPECIAL. 412 00:22:42,333 --> 00:22:44,767 IT'S ONLY THE SECOND WORLD IN THE SOLAR SYSTEM 413 00:22:44,767 --> 00:22:48,067 WHERE WE KNOW THERE'S LIQUID ON THE SURFACE. 414 00:22:51,333 --> 00:22:52,900 Narrator: AND LIKE EARTH, 415 00:22:52,900 --> 00:22:56,533 TITAN HAS A THICK NITROGEN-RICH ATMOSPHERE. 416 00:22:56,533 --> 00:22:58,667 BUT INSTEAD OF THE OXYGEN WE BREATHE, 417 00:22:58,667 --> 00:23:02,333 TITAN'S AIR IS SPIKED WITH CARBON-RICH MOLECULES 418 00:23:02,333 --> 00:23:06,433 THAT STAIN IT A DULL ORANGE. 419 00:23:06,433 --> 00:23:09,633 IT'S A SOUP OF METHANE AND ETHANE AND PROPANE 420 00:23:09,633 --> 00:23:11,133 AND ACETYLENE. 421 00:23:11,133 --> 00:23:13,200 UH, THE LIST OF ORGANIC MOLECULES IS LITERALLY 422 00:23:13,200 --> 00:23:15,500 HUNDREDS, HUNDREDS LONG THAT WE'VE DETECTED THERE. 423 00:23:18,200 --> 00:23:19,700 Narrator: TITAN'S COMPLEX COCKTAIL 424 00:23:19,700 --> 00:23:24,667 OF ATMOSPHERIC CHEMICALS INTRIGUE SCIENTISTS. 425 00:23:24,667 --> 00:23:27,333 BUT IT ALSO PUZZLES THEM, 426 00:23:27,333 --> 00:23:33,367 ESPECIALLY METHANE GAS, WHICH RAPIDLY DECAYS IN SUNLIGHT. 427 00:23:33,367 --> 00:23:35,800 SO EVEN A BILLION MILES FROM THE SUN, 428 00:23:35,800 --> 00:23:40,267 TITAN'S THICK HAZE SHOULD'VE LIFTED LONG AGO. 429 00:23:40,267 --> 00:23:44,267 A VAST SOURCE OF METHANE MUST BE REPLENISHING 430 00:23:44,267 --> 00:23:46,400 THE ORANGE SMOG. 431 00:23:46,400 --> 00:23:47,667 BEFORE CASSINI, 432 00:23:47,667 --> 00:23:49,167 SCIENTISTS ASSUMED THE WHOLE OF TITAN 433 00:23:49,167 --> 00:23:51,833 WAS COVERED IN MASSIVE IMPACT CRATERS. 434 00:23:51,833 --> 00:23:55,067 PERHAPS CRATER LAKES FILLED WITH LIQUID METHANE 435 00:23:55,067 --> 00:23:57,600 WERE EVAPORATING INTO THE ATMOSPHERE, 436 00:23:57,600 --> 00:24:01,433 SUPPLYING THE MISSING GAS. 437 00:24:01,433 --> 00:24:03,567 TO HELP PROVE THIS THEORY, 438 00:24:03,567 --> 00:24:07,567 CASSINI CARRIED A HITCHHIKER ALL THE WAY TO SATURN. 439 00:24:07,567 --> 00:24:11,800 THE HUYGENS LANDER RELEASED HIGH ABOVE TITAN'S EQUATOR 440 00:24:11,800 --> 00:24:17,167 PARACHUTED THROUGH THE CLOUDS, SNAPPING PHOTOGRAPHS AS IT FELL. 441 00:24:20,367 --> 00:24:21,900 Plait: AS IT WENT THROUGH THE ATMOSPHERE, 442 00:24:21,900 --> 00:24:23,233 IT TOOK A HUGE AMOUNT OF DATA 443 00:24:23,233 --> 00:24:27,133 AND THEN LANDED ON THE MOON ITSELF AND TOOK PICTURES. 444 00:24:27,133 --> 00:24:29,400 WHEN WE FIRST SAW THOSE PICTURES, 445 00:24:29,400 --> 00:24:31,600 IT WAS LIFE-CHANGING. 446 00:24:31,600 --> 00:24:35,433 Narrator: THERE WERE NO CRATERS. 447 00:24:35,433 --> 00:24:39,533 IT LOOKED LIKE FLOWING LIQUID HAD ONCE SHAPED THE LANDSCAPE, 448 00:24:39,533 --> 00:24:43,733 BUT AT THE LANDING SITE AND AS FAR AS HUYGENS COULD SEE, 449 00:24:43,733 --> 00:24:47,933 THAT LIQUID WAS LONG GONE. 450 00:24:47,933 --> 00:24:50,733 HUYGENS LANDED IN A SPOT ALMOST IDENTICAL 451 00:24:50,733 --> 00:24:52,400 TO WHAT WE'RE STANDING ON RIGHT NOW. 452 00:24:52,400 --> 00:24:54,633 IF WE LOOK ALL AROUND, 453 00:24:54,633 --> 00:24:57,867 WE CAN SEE THIS BLEAK, BARREN LANDSCAPE. 454 00:24:57,867 --> 00:24:59,667 WE SEE PEBBLES AND COBBLES 455 00:24:59,667 --> 00:25:01,333 THAT HAVE BEEN ROUNDED AND SMOOTHED 456 00:25:01,333 --> 00:25:03,233 BECAUSE THEY'VE COME THROUGH RIVER CHANNELS. 457 00:25:03,233 --> 00:25:05,600 WE SEE PLENTY OF THOSE AT THE HUYGENS LANDING SITE. 458 00:25:05,600 --> 00:25:08,567 UH, IN ADDITION TO THAT, WE SEE LOTS OF SAND. 459 00:25:09,967 --> 00:25:14,833 Narrator: THE DESERT HUYGENS LANDED IN IS HUGE. 460 00:25:14,833 --> 00:25:18,167 IT STRETCHES ALL THE WAY AROUND TITAN'S EQUATOR... 461 00:25:21,400 --> 00:25:24,967 WITH 300-FOOT TALL DUNES SCULPTED BY THE WIND 462 00:25:24,967 --> 00:25:28,533 JUST AS THEY ARE ON EARTH. 463 00:25:28,533 --> 00:25:31,800 IF THE VAST CRATER LAKES WEREN'T AT THE EQUATOR, 464 00:25:31,800 --> 00:25:35,200 THEY HAD TO BE AT TITAN'S POLES. 465 00:25:35,200 --> 00:25:38,233 CASSINI SCHEDULED A NUMBER OF ADDITIONAL FLYBYS 466 00:25:38,233 --> 00:25:43,067 TO LOOK FOR ANY SIGNS OF LIQUID. 467 00:25:43,067 --> 00:25:44,067 ONE OF THE INSTRUMENTS ONBOARD CASSINI 468 00:25:44,067 --> 00:25:46,233 IS BASICALLY A RADAR GUN. 469 00:25:46,233 --> 00:25:49,667 IT SHOOTS RADAR WAVES AT TITAN, AND THEY GET REFLECTED BACK. 470 00:25:49,667 --> 00:25:52,800 Narrator: AFTER TWO YEARS OF HUNTING WITH THIS INSTRUMENT, 471 00:25:52,800 --> 00:25:55,267 SCIENTISTS FINALLY GOT THE SIGNAL 472 00:25:55,267 --> 00:25:56,967 THEY WERE WAITING FOR. 473 00:25:56,967 --> 00:25:58,400 ONE OF THE THINGS IT FOUND 474 00:25:58,400 --> 00:26:00,200 IS THAT NEAR THE NORTH POLE OF TITAN 475 00:26:00,200 --> 00:26:02,967 WERE REGIONS THAT WERE NOT REFLECTING RADAR, 476 00:26:02,967 --> 00:26:05,067 AND THAT SOUNDS A LOT LIKE LIQUID. 477 00:26:05,067 --> 00:26:07,967 LIQUID ABSORBS THAT ENERGY AND DOESN'T REFLECT IT BACK. 478 00:26:07,967 --> 00:26:11,733 LATER OBSERVATIONS CLINCHED IT. 479 00:26:11,733 --> 00:26:13,300 Radebaugh: WHEN CASSINI FINALLY IMAGED 480 00:26:13,300 --> 00:26:15,800 THE NORTH POLAR REGIONS OF TITAN, 481 00:26:15,800 --> 00:26:17,967 IT -- IT FINALLY SAW THESE LAKES AND SEAS OF METHANE 482 00:26:17,967 --> 00:26:19,567 THAT WE'D BEEN LOOKING FOR, 483 00:26:19,567 --> 00:26:22,800 ONLY THEY WEREN'T CONTAINED IN IMPACT CRATERS LIKE WE THOUGHT. 484 00:26:22,800 --> 00:26:25,067 INSTEAD THEY'RE CONTAINED IN BIG LAKE BASINS 485 00:26:25,067 --> 00:26:26,833 THAT LOOK JUST LIKE THEY DO ON EARTH. 486 00:26:31,800 --> 00:26:33,200 [ BIRDS CAWING ] 487 00:26:33,200 --> 00:26:34,433 Narrator: BASIN LAKES LIKE THIS ONE 488 00:26:34,433 --> 00:26:36,133 IN MONO COUNTY, CALIFORNIA, 489 00:26:36,133 --> 00:26:40,533 FORM IN THE DEPRESSIONS LEFTOVER FROM TECTONIC ACTIVITY. 490 00:26:40,533 --> 00:26:42,933 THESE GEOLOGICAL FEATURES ON TITAN 491 00:26:42,933 --> 00:26:45,833 COULD ONLY MEAN ONE SHOCKING THING -- 492 00:26:45,833 --> 00:26:50,733 THE MOON WAS ALIVE WITH GEOLOGICAL ACTIVITY. 493 00:26:50,733 --> 00:26:53,233 Radebaugh: IF WE WERE SITTING ON THE MARGINS OF KRAKEN MARE, 494 00:26:53,233 --> 00:26:56,667 WHICH IS THE LARGEST SEA THAT WE SEE ON TITAN, 495 00:26:56,667 --> 00:26:58,533 THEN WE WOULD PROBABLY SEE SOMETHING VERY SIMILAR 496 00:26:58,533 --> 00:27:00,333 TO THIS LANDSCAPE. 497 00:27:00,333 --> 00:27:03,067 WE WOULD LOOK OUT ACROSS A FAIRLY CALM SURFACE, 498 00:27:03,067 --> 00:27:05,633 WE THINK THE WINDS ARE NOT VERY STRONG ON TITAN. 499 00:27:05,633 --> 00:27:09,167 AND SO WE'D HAVE THIS CALM LAKE OF METHANE AND ETHANE. 500 00:27:09,167 --> 00:27:11,867 AND IN THE DISTANCE WE WOULD SEE HILLS AND MOUNTAINS 501 00:27:11,867 --> 00:27:13,400 THAT HAVE FORMED ON TITAN 502 00:27:13,400 --> 00:27:15,133 PROBABLY THROUGH TECTONIC PROCESSES 503 00:27:15,133 --> 00:27:17,467 IN MUCH THE SAME WAY THAT MOUNTAINS ARE BUILT ON EARTH. 504 00:27:17,467 --> 00:27:21,300 Narrator: EXCEPT ON TITAN, IT'S SO COLD, 505 00:27:21,300 --> 00:27:25,333 THE VOLCANOES SPEW WATER, NOT LAVA. 506 00:27:25,333 --> 00:27:32,300 AND THE MOUNTAINS AND LAKE BASINS ARE SOLID ICE. 507 00:27:32,300 --> 00:27:36,400 AT FIRST, SCIENTISTS THOUGHT THAT METHANE EVAPORATING 508 00:27:36,400 --> 00:27:40,567 FROM THESE LAKES GENERATED TITAN'S SMOG. 509 00:27:40,567 --> 00:27:44,233 BUT WHEN CASSINI FLEW BY TO MEASURE THE LAKES AGAIN, 510 00:27:44,233 --> 00:27:46,500 THE LEVELS APPEAR TO BE THE SAME. 511 00:27:46,500 --> 00:27:50,467 THE LAKES DIDN'T LOOK LIKE THEY WERE EVAPORATING AT ALL. 512 00:27:50,467 --> 00:27:52,333 SCIENTISTS WERE STUMPED. 513 00:27:52,333 --> 00:27:54,433 EITHER THE LAKES WEREN'T THE SOURCE 514 00:27:54,433 --> 00:27:56,367 OF ATMOSPHERIC METHANE 515 00:27:56,367 --> 00:28:00,133 OR THEY WERE SOMEHOW BEING REFILLED. 516 00:28:00,133 --> 00:28:03,167 PLANETARY GEOLOGIST, JANI RADEBAUGH, 517 00:28:03,167 --> 00:28:05,967 BELIEVES A CRUCIAL CLUE TO THE MISSING METHANE 518 00:28:05,967 --> 00:28:09,567 LIES IN THE FORMATION OF ROCKY DEPOSITS CALLED TUFA. 519 00:28:09,567 --> 00:28:12,067 [ WATER BUBBLING ] 520 00:28:12,067 --> 00:28:14,333 Narrator: THEY'RE FOUND HERE AT MONO LAKE, 521 00:28:14,333 --> 00:28:17,667 WHERE CLEAN SPRING WATER RISES UP FROM THE GROUND 522 00:28:17,667 --> 00:28:22,500 INTO THE MINERAL-RICH LAKE WHERE THE TWO WATER TYPES REACT. 523 00:28:26,333 --> 00:28:29,933 THIS IS VERY EXCITING BECAUSE THIS COULD BE A CLUE 524 00:28:29,933 --> 00:28:31,467 TO THE MISSING METHANE ON TITAN. 525 00:28:31,467 --> 00:28:35,600 SO IT'S ROCK THAT HAS BEEN FORMED FROM THE CHEMICALS 526 00:28:35,600 --> 00:28:37,200 CONTAINED IN TWO FLUIDS. 527 00:28:37,200 --> 00:28:40,733 THERE IS WATER THAT'S EMERGING AT THE MARGIN OF THE LAKE. 528 00:28:40,733 --> 00:28:42,133 IT'S INTERACTING WITH THE LAKE WATER 529 00:28:42,133 --> 00:28:44,233 WHICH HAS A VERY DIFFERENT CHEMISTRY 530 00:28:44,233 --> 00:28:46,733 AND ALL OF THE CHEMICALS THAT ARE DISSOLVED 531 00:28:46,733 --> 00:28:49,833 COMBINE WITH EACH OTHER AND CREATE THIS ROCK. 532 00:28:49,833 --> 00:28:53,467 Narrator: RADAR IMAGES OF TITAN'S LARGEST LAKE 533 00:28:53,467 --> 00:28:56,233 REVEAL ROCKY STRUCTURES AROUND THE MARGINS 534 00:28:56,233 --> 00:29:00,367 THAT LOOK JUST LIKE MONO LAKE'S TUFA. 535 00:29:00,367 --> 00:29:03,167 TITAN'S TUFA, IF THAT'S WHAT THEY ARE, 536 00:29:03,167 --> 00:29:06,533 COULD BE EVIDENCE OF A LAYER OF LIQUID METHANE 537 00:29:06,533 --> 00:29:09,233 THAT SITS ABOVE TITAN'S FROZEN CORE 538 00:29:09,233 --> 00:29:12,900 AND RISES AND SPRINGS TO FEED ITS LAKES 539 00:29:12,900 --> 00:29:16,767 JUST LIKE SPRING WATER RISES TO FEED MONO LAKE. 540 00:29:16,767 --> 00:29:18,833 Radebaugh: SO WHEN THOSE METHANE SPRINGS COME IN, 541 00:29:18,833 --> 00:29:23,200 THEY INTERACT WITH THE LAKES AND A ROCK PRECIPITATES OUT. 542 00:29:23,200 --> 00:29:25,667 SO WE SEE THESE ORGANIC ROCKS 543 00:29:25,667 --> 00:29:27,967 DOTTING THE MARGINS OF THE LAKES. 544 00:29:27,967 --> 00:29:29,700 AND ALMOST CERTAINLY THERE'S ALSO METHANE 545 00:29:29,700 --> 00:29:31,733 JUST BUBBLING UP AND EMERGING 546 00:29:31,733 --> 00:29:33,400 AT THE MARGINS OF THE LAKE AS WELL. 547 00:29:35,767 --> 00:29:37,200 Narrator: IF JANI IS RIGHT, 548 00:29:37,200 --> 00:29:41,767 TITAN'S LAKES DO EVAPORATE, FEEDING THE ATMOSPHERIC SMOG, 549 00:29:41,767 --> 00:29:43,600 BUT THEY'RE CONSTANTLY REPLENISHED 550 00:29:43,600 --> 00:29:48,633 BY UNDERGROUND METHANE SPRINGS REPLACING THE LOST FLUID. 551 00:29:52,533 --> 00:29:55,467 TITAN IS NO DEAD WORLD. 552 00:29:55,467 --> 00:30:01,000 IT'S ALIVE WITH ACTIVE GEOLOGY AND COMPLEX CHEMISTRY. 553 00:30:01,000 --> 00:30:03,700 AND IT MIGHT BE ALIVE WITH SOMETHING ELSE -- 554 00:30:03,700 --> 00:30:05,933 SOMETHING REALLY BIG. 555 00:30:19,467 --> 00:30:21,800 Narrator: WE USED TO THINK THAT SATURN WAS TOO FAR 556 00:30:21,800 --> 00:30:28,333 FROM THE SUN AND TOO COLD TO PLAY HOST TO ANYTHING DRAMATIC. 557 00:30:28,333 --> 00:30:32,267 WE COULD NOT HAVE BEEN MORE WRONG. 558 00:30:32,267 --> 00:30:35,800 THE PLANET BOILS AND BANGS WITH ACTIVE WEATHER -- 559 00:30:35,800 --> 00:30:39,300 STORMS, LIGHTNING, AND AURORAS. 560 00:30:39,300 --> 00:30:42,900 THE RINGS CONSTANTLY EVOLVE. 561 00:30:45,833 --> 00:30:50,433 AND THE MOONS AREN'T THE FROZEN SNOWBALLS WE EXPECTED. 562 00:30:50,433 --> 00:30:56,000 THEY'RE SHAPED BY ACTIVE GEOLOGY WITH WARM WATER GEYSERS 563 00:30:56,000 --> 00:31:00,133 AND LAKES OF LIQUID METHANE. 564 00:31:00,133 --> 00:31:04,633 AND NOW ON SATURN'S LARGEST MOON, TITAN, 565 00:31:04,633 --> 00:31:10,467 SCIENTISTS MAY HAVE UNCOVERED THE FIRST TANGIBLE EVIDENCE... 566 00:31:10,467 --> 00:31:14,600 OF EXTRATERRESTRIAL LIFE. 567 00:31:14,600 --> 00:31:16,400 McKay: OUR SEARCH FOR LIFE HAS BEEN 568 00:31:16,400 --> 00:31:19,067 FOCUSED ON LIQUID WATER -- FOLLOW THE WATER. 569 00:31:19,067 --> 00:31:20,833 I THINK IT'S A GOOD STRATEGY. 570 00:31:20,833 --> 00:31:23,233 BUT I THINK WE ARE LIMITING OURSELVES IF WE THINK THAT 571 00:31:23,233 --> 00:31:25,500 THAT'S THE ONLY PLACE TO LOOK. 572 00:31:25,500 --> 00:31:28,367 I THINK LIQUIDS MAY BE INTERESTING 573 00:31:28,367 --> 00:31:30,533 EVEN IF THEY'RE NOT WATER. 574 00:31:32,300 --> 00:31:34,333 Narrator: ASTROBIOLOGIST, CHRIS McKAY, 575 00:31:34,333 --> 00:31:36,367 BELIEVES THAT LIFE ON TITAN 576 00:31:36,367 --> 00:31:39,233 MAY HAVE EVOLVED TO LIVE IN LIQUID METHANE, 577 00:31:39,233 --> 00:31:42,100 NOT LIQUID WATER. 578 00:31:42,100 --> 00:31:43,733 BUT TITAN IS SO COLD, 579 00:31:43,733 --> 00:31:48,067 SIMPLE LIFE WOULD PLAY BY A VERY DIFFERENT SET OF RULES 580 00:31:48,067 --> 00:31:51,300 WHERE BIGGER IS BETTER. 581 00:31:51,300 --> 00:31:52,500 McKay: WHEN WE GO TO OTHER WORLDS, 582 00:31:52,500 --> 00:31:53,900 WE'RE GONNA BE LOOKING FOR BACTERIA, 583 00:31:53,900 --> 00:31:56,200 AND WE ASSUME THAT THEY'RE GONNA BE VERY SMALL. 584 00:31:56,200 --> 00:31:59,833 BUT YOU COULD ASK THE QUESTION, WHY ARE BACTERIA SO SMALL? 585 00:31:59,833 --> 00:32:04,500 WELL, I THINK THE ANSWER IS BECAUSE THEY LIVE IN WATER. 586 00:32:04,500 --> 00:32:08,600 Narrator: ON EARTH, BACTERIA DON'T NEED TO GROW BIG 587 00:32:08,600 --> 00:32:11,300 IN ORDER TO THRIVE. 588 00:32:11,300 --> 00:32:13,400 WATER DISSOLVES ALMOST EVERYTHING, 589 00:32:13,400 --> 00:32:16,133 SO IT PROVIDES A NUTRIENT-RICH ENVIRONMENT 590 00:32:16,133 --> 00:32:20,767 WHERE SMALL AND SIMPLE BRING SUCCESS. 591 00:32:20,767 --> 00:32:23,800 YOU GO TO TITAN WHERE THE LIQUID IS LIQUID METHANE, 592 00:32:23,800 --> 00:32:25,933 LIQUID ETHANE, VERY DIFFERENT FROM WATER. 593 00:32:25,933 --> 00:32:28,167 THERE'S NO REASON AN ORGANISM SHOULD BE SMALL. 594 00:32:28,167 --> 00:32:30,567 IN FACT, QUITE THE OPPOSITE. IT SHOULD BE HUGE. 595 00:32:30,567 --> 00:32:35,267 Narrator: McKAY ENVISIONS ENORMOUS SINGLE-CELLED ORGANISMS 596 00:32:35,267 --> 00:32:39,633 AROUND TITAN'S SHORES, LOOKING LIKE SHEETS OF PAPER. 597 00:32:39,633 --> 00:32:42,200 THEIR HUGE SURFACE AREA WOULD MAXIMIZE 598 00:32:42,200 --> 00:32:47,167 THE UPTAKE OF FOOD FROM THE NUTRIENT-POOR LIQUID METHANE. 599 00:32:47,167 --> 00:32:48,833 I PREDICT IF THERE'S LIFE ON TITAN 600 00:32:48,833 --> 00:32:49,967 LIVING IN LIQUID METHANE, 601 00:32:49,967 --> 00:32:51,500 YOU WON'T NEED A MICROSCOPE TO SEE IT. 602 00:32:51,500 --> 00:32:53,100 YOU'LL NEED A YARDSTICK. 603 00:32:57,067 --> 00:33:00,633 Narrator: WHEN CASSINI RELEASED THE HUYGENS PROBE 604 00:33:00,633 --> 00:33:03,200 HIGH ABOVE THE CLOUD TOPS OF TITAN, 605 00:33:03,200 --> 00:33:06,133 McKAY REALIZED HE HAD AN OPPORTUNITY 606 00:33:06,133 --> 00:33:09,933 TO BOLSTER HIS THEORIES OF LIFE ON THE SURFACE. 607 00:33:09,933 --> 00:33:14,433 HIS METHANE-LOVING LIFE-FORMS MUST BE EATING TO SURVIVE. 608 00:33:14,433 --> 00:33:16,867 PERHAPS HUYGENS' DELICATE SENSORS 609 00:33:16,867 --> 00:33:21,700 WOULD PICK UP EVIDENCE OF GROUND LEVEL FEASTING. 610 00:33:21,700 --> 00:33:24,333 AS HUYGENS WAS ON ITS WAY TO TITAN, 611 00:33:24,333 --> 00:33:27,533 I'M SITTING IN A HOTEL ROOM WRITING UP A PAPER SAYING, 612 00:33:27,533 --> 00:33:29,533 HEY, WHAT IF THERE'S LIFE ON TITAN? 613 00:33:29,533 --> 00:33:31,900 WHAT WOULD IT EAT? AND HOW WOULD WE DETECT IT? 614 00:33:31,900 --> 00:33:34,133 HOW WOULD THIS PROBE FLYING THROUGH THE ATMOSPHERE 615 00:33:34,133 --> 00:33:35,633 DETECT IT? 616 00:33:35,633 --> 00:33:38,100 LITERALLY THE DAY HUYGENS LANDED, 617 00:33:38,100 --> 00:33:40,700 I SUBMITTED THIS PAPER TO THE JOURNAL, 618 00:33:40,700 --> 00:33:43,367 PREDICTING THAT IF THERE WAS LIFE ON TITAN, 619 00:33:43,367 --> 00:33:45,567 IT WOULD EAT HYDROGEN AND THE PROBE 620 00:33:45,567 --> 00:33:48,067 WOULD BE ABLE TO MEASURE THIS DEPLETION OF HYDROGEN. 621 00:33:48,067 --> 00:33:52,300 SO LET'S LOOK FOR HYDROGEN. 622 00:33:52,300 --> 00:33:55,400 Narrator: HUYGENS PARACHUTES THROUGH TITAN'S ATMOSPHERE, 623 00:33:55,400 --> 00:33:57,967 SAMPLING THE GASES AS IT GOES. 624 00:33:57,967 --> 00:34:00,633 THE UPPER ATMOSPHERE HAS PLENTY OF HYDROGEN, 625 00:34:00,633 --> 00:34:02,200 SO DO THE MIDDLE LAYERS, 626 00:34:02,200 --> 00:34:07,600 BUT AT GROUND LEVEL, THERE'S A SURPRISE RESULT -- 627 00:34:07,600 --> 00:34:10,133 AN APPARENTLY DROP-OFF IN THE CONCENTRATION 628 00:34:10,133 --> 00:34:12,433 OF HYDROGEN IN THE AIR. 629 00:34:12,433 --> 00:34:17,667 SOMETHING OR PERHAPS SOMEONE WAS USING IT UP. 630 00:34:19,400 --> 00:34:23,733 WHEN I HEARD A REPORT THAT THERE WAS A DEPLETION OF HYDROGEN, 631 00:34:23,733 --> 00:34:26,800 I -- MY HEART RACED 'CAUSE I THOUGHT, 632 00:34:26,800 --> 00:34:28,400 IF THIS IS -- IF THIS IS HARD DATA 633 00:34:28,400 --> 00:34:30,133 FOR DEPLETION OF HYDROGEN, 634 00:34:30,133 --> 00:34:33,267 I CAN'T IMAGINE ANY OTHER WAY BESIDES BIOLOGY TO EXPLAIN THAT. 635 00:34:35,200 --> 00:34:37,067 IT'S EXCITING IN THAT IT'S CONSISTENT 636 00:34:37,067 --> 00:34:39,200 WITH WHAT WE PREDICTED, 637 00:34:39,200 --> 00:34:41,133 BUT WE HAVE TO WAIT FOR THIS TO BE CONFIRMED 638 00:34:41,133 --> 00:34:43,967 BY OTHER CALCULATIONS, BY DIRECT MEASUREMENTS, 639 00:34:43,967 --> 00:34:46,933 AND SO ON. 640 00:34:46,933 --> 00:34:50,900 Narrator: IF FUTURE MISSIONS CAN CONFIRM METHANE-BASED LIFE 641 00:34:50,900 --> 00:34:54,600 ON TITAN, IT WILL SURELY BE THE GREATEST DISCOVERY 642 00:34:54,600 --> 00:34:56,167 IN THE HISTORY OF SCIENCE. 643 00:34:56,167 --> 00:35:01,367 BECAUSE THIS LOW TEMPERATURE BIOLOGY MUST HAVE ARISEN 644 00:35:01,367 --> 00:35:06,600 INDEPENDENTLY OF LIFE ON EARTH. 645 00:35:06,600 --> 00:35:10,200 IF WE DISCOVER LIFE, LET'S SAY ON MARS, 646 00:35:10,200 --> 00:35:12,367 THERE WILL ALWAYS BE THE POSSIBILITY 647 00:35:12,367 --> 00:35:14,533 THAT ROCKS AND ICE AND BITS OF MATERIAL 648 00:35:14,533 --> 00:35:16,200 COULD'VE BEEN EXCHANGED. 649 00:35:16,200 --> 00:35:18,133 BUT THE CHANCES OF THAT HAPPENING FROM EARTH 650 00:35:18,133 --> 00:35:21,533 ALL THE WAY TO SATURN ARE NEXT TO NOTHING. 651 00:35:21,533 --> 00:35:24,633 IF WE FIND A SECOND EXAMPLE OF LIFE IN OUR SOLAR SYSTEM 652 00:35:24,633 --> 00:35:26,567 ESPECIALLY IN A PLACE LIKE TITAN 653 00:35:26,567 --> 00:35:30,333 WHICH IS SO ALIEN TO THE EARTH, SO COLD AND SO DIFFERENT, 654 00:35:30,333 --> 00:35:33,767 THAT TELLS US SOMETHING EXCRUCIATINGLY IMPORTANT. 655 00:35:33,767 --> 00:35:37,567 AND THAT IS THAT LIFE MUST BE EVERYWHERE IN THE UNIVERSE. 656 00:35:45,200 --> 00:35:48,233 Narrator: ROBOTIC MISSIONS OFFER TANTALIZING HINTS 657 00:35:48,233 --> 00:35:51,767 OF SIMPLE LIFE ON ENCELADUS AND TITAN. 658 00:35:51,767 --> 00:35:56,633 BUT IS SATURN'S REALM ONLY FIT FOR GIANT BACTERIA 659 00:35:56,633 --> 00:36:02,300 OR IS IT A PLACE WE HUMANS COULD ONE DAY CALL HOME? 660 00:36:16,233 --> 00:36:20,767 Narrator: SATURN ORBITS A BILLION MILES FROM THE SUN. 661 00:36:20,767 --> 00:36:24,300 SO FAR OUT IT TAKES AN HOUR FOR ITS REFLECTED LIGHT 662 00:36:24,300 --> 00:36:28,200 TO REACH OUR EYES. 663 00:36:28,200 --> 00:36:29,967 YET THE FUTURE OF OUR CIVILIZATION 664 00:36:29,967 --> 00:36:34,167 MAY REST ON HUMANS ONE DAY COLONIZING THE MOONS 665 00:36:34,167 --> 00:36:37,867 SURROUNDING THIS GAS GIANT PLANET. 666 00:36:37,867 --> 00:36:40,867 IT WON'T BE EASY, BUT SATURN HAS SOMETHING 667 00:36:40,867 --> 00:36:43,267 WORTH THE TROUBLE -- 668 00:36:43,267 --> 00:36:47,400 A MAGICAL SOURCE OF FUEL CALLED HELIUM-3 669 00:36:47,400 --> 00:36:50,533 THAT CAN SATISFY OUR INCREASING HUNGER FOR ENERGY 670 00:36:50,533 --> 00:36:54,333 FOR MILLIONS OF YEARS. 671 00:36:54,333 --> 00:36:56,800 SOME FUTURISTS BELIEVE THAT WE HAVE TO HAVE 672 00:36:56,800 --> 00:36:59,400 A COMMERCIAL INCENTIVE TO GOING TO SATURN. 673 00:36:59,400 --> 00:37:03,633 NOT JUST TO MINE THE MINERALS OF THE MOONS OF SATURN, 674 00:37:03,633 --> 00:37:09,067 BUT ALSO TO HARVEST FUEL IN THE FORM OF HELIUM-3. 675 00:37:09,067 --> 00:37:11,467 HELIUM-3 IS A RARE SUBSTANCE THAT WE CAN USE 676 00:37:11,467 --> 00:37:16,333 IN FUSION ENGINES TO PROVIDE PERHAPS UNLIMITED ENERGY. 677 00:37:16,333 --> 00:37:21,067 Narrator: HELIUM-3 MAY VERY WELL REPLACE OIL AS THE FUEL 678 00:37:21,067 --> 00:37:24,133 TO TAKE US INTO THE CENTURIES TO COME. 679 00:37:24,133 --> 00:37:26,933 WITH ITS SINGLE NEUTRON AND TWIN PROTONS, 680 00:37:26,933 --> 00:37:31,133 HELIUM-3 IS UNIQUELY SUITED TO A FORM OF ENERGY PRODUCTION 681 00:37:31,133 --> 00:37:32,967 CALLED FUSION -- 682 00:37:32,967 --> 00:37:37,700 THE SAME PROCESS THAT BURNS IN THE HEART OF A STAR. 683 00:37:37,700 --> 00:37:39,533 WHEN TWO NUCLEI ARE CRUSHED TOGETHER 684 00:37:39,533 --> 00:37:42,300 UNDER ENORMOUS PRESSURE, THEY FUSE, 685 00:37:42,300 --> 00:37:48,167 CREATING A NEW HEAVIER ATOM AND A BURST OF PURE ENERGY. 686 00:37:48,167 --> 00:37:52,433 BEST OF ALL, HELIUM-3 DOESN'T RELEASE 687 00:37:52,433 --> 00:37:54,433 ANY OF THE HARMFUL RADIATION 688 00:37:54,433 --> 00:37:58,067 ASSOCIATED WITH OTHER FUSION FUELS. 689 00:37:58,067 --> 00:38:00,733 THE ONLY TROUBLE WITH HELIUM-3 -- 690 00:38:00,733 --> 00:38:04,700 THERE'S PRECIOUS LITTLE TO BE FOUND ON EARTH. 691 00:38:04,700 --> 00:38:07,233 NOW YOU COULD FIND SOME HELIUM-3 ON THE MOON, 692 00:38:07,233 --> 00:38:10,600 BUT THE MAJOR SUPPLIES OF HELIUM-3 IN OUR SOLAR SYSTEM 693 00:38:10,600 --> 00:38:13,233 ARE LOCATED IN THE ATMOSPHERES OF THE GIANT PLANETS. 694 00:38:13,233 --> 00:38:16,333 I CALL THE GAS GIANTS 695 00:38:16,333 --> 00:38:18,133 "THE PERSIAN GULF OF THE SOLAR SYSTEM" 696 00:38:18,133 --> 00:38:21,867 BECAUSE THEY ARE THE LOCATION OF ITS PRIMARY ENERGY RESOURCES 697 00:38:21,867 --> 00:38:24,933 OUTSIDE OF THE SUN. 698 00:38:24,933 --> 00:38:26,100 Narrator: THE GAS GIANTS PROVIDE 699 00:38:26,100 --> 00:38:30,233 A NEAR INEXHAUSTIBLE SUPPLY OF HELIUM-3. 700 00:38:30,233 --> 00:38:33,800 BUT HOW COULD WE EXTRACT IT? 701 00:38:33,800 --> 00:38:35,600 JUPITER HAS THE MOST. 702 00:38:35,600 --> 00:38:38,900 BUT THE PLANET'S IMMENSE GRAVITY AND DANGEROUS RADIATION BELTS 703 00:38:38,900 --> 00:38:43,567 MAKE IT A NO-GO FOR MINING. 704 00:38:43,567 --> 00:38:48,067 NEPTUNE AND URANUS ARE WAY TOO FAR AWAY TO BE PRACTICAL. 705 00:38:48,067 --> 00:38:51,700 THAT LEAVES SATURN WITH RELATIVELY LOW GRAVITY 706 00:38:51,700 --> 00:38:53,667 FOR SUCH A BIG PLANET. 707 00:38:53,667 --> 00:38:59,433 AND FAR LOWER LEVELS OF DEADLY RADIATION THAN AROUND JUPITER. 708 00:38:59,433 --> 00:39:02,733 IF WE'RE GONNA HAVE A FUTURE HUMAN ECONOMY BASED ON 709 00:39:02,733 --> 00:39:05,333 USING CONTROLLED FUSION AND HELIUM-3, 710 00:39:05,333 --> 00:39:08,067 SATURN IS THE DESTINATION OF CHOICE. 711 00:39:08,067 --> 00:39:13,400 Narrator: FUTURISTS ENVISION WINGED DRONES FLYING THROUGH 712 00:39:13,400 --> 00:39:19,667 THE UPPER ATMOSPHERE OF SATURN, SCOOPING UP GASES. 713 00:39:19,667 --> 00:39:23,433 BUT WHERE TO PROCESS THIS SUPER FUEL? 714 00:39:23,433 --> 00:39:28,567 THE IDEAL BASE OF OPERATIONS WOULD CLEARLY BE TITAN. 715 00:39:30,767 --> 00:39:33,233 WITH GRAVITY AS GENTLE AS OUR MOONS 716 00:39:33,233 --> 00:39:35,333 AND A THICK EARTH-LIKE ATMOSPHERE, 717 00:39:35,333 --> 00:39:40,667 TITAN IS SURPRISINGLY SUITABLE FOR A HUMAN OUTPOST. 718 00:39:40,667 --> 00:39:43,067 Zubrin: WE COULD HAVE HUGE DOME SETTLEMENTS ON TITAN. 719 00:39:43,067 --> 00:39:45,467 THEY WOULD NOT HAVE TO BE STRONG ENOUGH TO HOLD PRESSURE. 720 00:39:45,467 --> 00:39:47,667 THEY COULD JUST BE THIN, INFLATABLE MEMBRANES. 721 00:39:47,667 --> 00:39:50,633 YOU COULD HAVE DOME CITIES LIKE YOU SEE IN SCIENCE FICTION 722 00:39:50,633 --> 00:39:53,967 WHICH ARE REALLY NOT POSSIBLE IN PLACES LIKE THE MOON. 723 00:39:53,967 --> 00:39:56,800 Narrator: WALKING OUT ONTO THE SURFACE OF TITAN 724 00:39:56,800 --> 00:40:00,267 WOULD BE MUCH EASIER THAN ON THE MOON OR ON MARS. 725 00:40:00,267 --> 00:40:02,200 THE PRESSURE ON TITAN IS KIND OF NICE. 726 00:40:02,200 --> 00:40:05,100 IT'S 1 1/2 TIMES EARTH PRESSURE. 727 00:40:05,100 --> 00:40:07,100 YOU WOULD NEED A SOURCE OF OXYGEN. 728 00:40:07,100 --> 00:40:09,000 AND YOU NEED A VERY WARM COAT. 729 00:40:09,000 --> 00:40:12,867 BUT IT WOULDN'T FEEL AS COLD AS YOU MIGHT THINK 730 00:40:12,867 --> 00:40:18,400 BECAUSE THE ATMOSPHERE IS CALM AND THERE'S NOT STRONG WIND. 731 00:40:18,400 --> 00:40:20,367 I THINK A COAT LIKE YOU MIGHT WEAR IN ANTARCTICA 732 00:40:20,367 --> 00:40:21,800 MIGHT BE ADEQUATE. 733 00:40:21,800 --> 00:40:24,533 SO YOU CAN IMAGINE SOMEBODY STEPPING OUT OF THE SPACESHIP, 734 00:40:24,533 --> 00:40:27,767 HAVING A PARKA ON, A MASK, LIKE A S.C.U.B.A. MASK 735 00:40:27,767 --> 00:40:29,467 TO PROVIDE OXYGEN, 736 00:40:29,467 --> 00:40:31,567 AND LITERALLY WALKING OUT ON THE SURFACE. 737 00:40:31,567 --> 00:40:36,100 Narrator: TITAN'S LOW GRAVITY AND DENSE ATMOSPHERE 738 00:40:36,100 --> 00:40:40,367 COULD EVEN SEND US SOARING FROM PLACE TO PLACE. 739 00:40:40,367 --> 00:40:41,867 LET'S SAY YOU HAD, YOU KNOW, 740 00:40:41,867 --> 00:40:43,600 IT'S A LITTLE BIT OF A WING ON YOUR ARM, 741 00:40:43,600 --> 00:40:45,067 AND YOU STARTED TO FLAP YOUR ARMS. 742 00:40:45,067 --> 00:40:47,100 REMEMBER IT'S ALMOST LIKE YOU'RE -- YOU'RE ON THE MOON, 743 00:40:47,100 --> 00:40:48,667 BUT WITH A THICK ATMOSPHERE. 744 00:40:48,667 --> 00:40:50,400 AND YOU'D REALLY BE ABLE TO LIFT YOURSELF 745 00:40:50,400 --> 00:40:52,633 OFF THE SURFACE, MAYBE FLY, JUST A LITTLE BIT. 746 00:40:57,567 --> 00:40:59,867 Narrator: WHEN THE HELIUM-3 TRADE ROUTE HAS OPENED 747 00:40:59,867 --> 00:41:03,100 AND THE EARTH BECOMES A FUSION ECONOMY, 748 00:41:03,100 --> 00:41:04,900 A NEW GENERATION OF ROCKETS 749 00:41:04,900 --> 00:41:08,067 WILL OPEN UP INTERPLANETARY TRAVEL TO EVERYONE, 750 00:41:08,067 --> 00:41:13,167 TAKING HUMANS TO MARS AND JUPITER, 751 00:41:13,167 --> 00:41:16,067 NOT IN YEARS, BUT IN MONTHS. 752 00:41:18,067 --> 00:41:22,200 AND HELIUM-3 MIGHT EVEN POWER ADVENTURE TOURISM 753 00:41:22,200 --> 00:41:24,533 TO SATURN ITSELF. 754 00:41:24,533 --> 00:41:25,967 Plait: YOU CAN IMAGINE IN A HUNDRED YEARS 755 00:41:25,967 --> 00:41:28,067 WHEN SPACE TRAVEL IS EASY 756 00:41:28,067 --> 00:41:29,833 AND THERE WILL BE HOTELS ORBITING THE MOON AND MARS 757 00:41:29,833 --> 00:41:31,933 AND EVERYTHING, WHAT WOULD BE THE ONE? 758 00:41:31,933 --> 00:41:34,733 WHAT WOULD BE THE PLACE, RIGHT, TO GO? 759 00:41:34,733 --> 00:41:36,167 IT WOULD BE SATURN. 760 00:41:40,467 --> 00:41:43,933 Porco: I WOULD HOPE ONE DAY THAT THERE IS SUCH A THING 761 00:41:43,933 --> 00:41:48,233 AS SPACE TOURISM AND PEOPLE CAN VISIT PLACES LIKE ENCELADUS. 762 00:41:48,233 --> 00:41:49,367 IT SHOULD BE CALLED 763 00:41:49,367 --> 00:41:51,167 THE ENCELADUS INTERPLANETARY GEYSER PARK 764 00:41:51,167 --> 00:41:54,267 BECAUSE IT WOULD BE A PHENOMENAL PLACE TO JUST GO VISIT. 765 00:41:57,833 --> 00:42:00,467 STANDING ON ENCELADUS WOULD BE AN AMAZING SIGHT. 766 00:42:00,467 --> 00:42:03,167 ALL OF THIS FROST CONDENSING BACK OUT ON THE SURFACE 767 00:42:03,167 --> 00:42:05,333 MAKES AN INCREDIBLY BRILLIANT WHITE. 768 00:42:05,333 --> 00:42:07,567 IT'S GOT SOME OF THE BEST POWDER SNOW FOR SKIING ANYWHERE 769 00:42:07,567 --> 00:42:08,833 IN THE SOLAR SYSTEM. 770 00:42:13,833 --> 00:42:15,833 Plait: YOU COULD GET CLOSE ENOUGH TO ACTUALLY 771 00:42:15,833 --> 00:42:18,300 SEE THE INDIVIDUAL RINGS, 772 00:42:18,300 --> 00:42:21,067 MAYBE EVEN SEE THE LITTLE MOONS IN THE GAPS SCULPTING 773 00:42:21,067 --> 00:42:22,967 AND PULLING AND PUSHING AND PRODDING, 774 00:42:22,967 --> 00:42:26,533 SHEPHERDING THOSE RING PARTICLES AROUND. 775 00:42:26,533 --> 00:42:28,167 YOU COULD GO BACK OVER AND OVER AGAIN, 776 00:42:28,167 --> 00:42:31,533 AND IT WOULD ALWAYS BE ALIEN AND EXOTIC AND EXCITING. 777 00:42:35,267 --> 00:42:39,733 Narrator: FROM A COLD, DEAD JEWEL IN OUR TELESCOPES 778 00:42:39,733 --> 00:42:43,967 TO A PLACE ALIVE WITH MAGIC AND MAYHEM -- 779 00:42:43,967 --> 00:42:47,533 SATURN AND ITS WORLDS HAVE COME ALIVE 780 00:42:47,533 --> 00:42:50,967 AND MAY HARBOR LIFE ITSELF. 781 00:42:50,967 --> 00:42:55,633 SOMEDAY SOON, THIS PLANET COULD REMAKE OUR UNIVERSE, 782 00:42:55,633 --> 00:43:00,067 AND NOTHING WILL EVER BE THE SAME.