1 00:00:39,780 --> 00:00:37,950 many of us expected this would be a 2 00:00:41,580 --> 00:00:39,790 mission of major discovery but none of 3 00:00:43,680 --> 00:00:41,590 us really expected the degree of 4 00:00:46,049 --> 00:00:43,690 discovery the degree of diversity which 5 00:00:49,280 --> 00:00:46,059 we found in the outer solar system we 6 00:00:52,410 --> 00:00:49,290 were lucky we had the unique opportunity 7 00:00:55,890 --> 00:00:52,420 to explore planets that man had never 8 00:00:58,470 --> 00:00:55,900 been to before but Voyager didn't only 9 00:01:02,429 --> 00:00:58,480 carry sophisticated instrumentation it 10 00:01:06,210 --> 00:01:02,439 carried the hearts and the minds of its 11 00:01:10,109 --> 00:01:06,220 creators and all of us who were 12 00:01:13,289 --> 00:01:10,119 privileged enough to see what it saw and 13 00:01:15,690 --> 00:01:13,299 it will be unique for a long time 14 00:01:19,499 --> 00:01:15,700 because there isn't anything else out 15 00:01:23,820 --> 00:01:19,509 there to to explore for which you can 16 00:01:27,030 --> 00:01:23,830 get as much return from a single system 17 00:01:32,090 --> 00:01:27,040 I think Voyager will be remembered as 18 00:01:35,670 --> 00:01:32,100 part of the few decades where human race 19 00:01:38,030 --> 00:01:35,680 left its planet and Voyager will be a 20 00:01:40,560 --> 00:01:38,040 main chapter in that book 21 00:01:43,980 --> 00:01:40,570 Voyager kind of opened up the outer 22 00:01:46,320 --> 00:01:43,990 planets to everybody and I think they 23 00:01:48,719 --> 00:01:46,330 were vastly more interesting to me 24 00:01:51,630 --> 00:01:48,729 expected up to and including maybe even 25 00:01:53,580 --> 00:01:51,640 especially Neptune you only explore 26 00:01:59,300 --> 00:01:53,590 explore the solar system for the first 27 00:01:59,310 --> 00:02:11,520 and we did it 28 00:02:15,960 --> 00:02:14,400 the outer planets are giant planets 29 00:02:18,180 --> 00:02:15,970 they're distinctly different than the 30 00:02:20,460 --> 00:02:18,190 smaller rocky objects in the inner solar 31 00:02:23,670 --> 00:02:20,470 system such as Earth Mars Venus and 32 00:02:26,430 --> 00:02:23,680 Mercury and Voyager was designed to open 33 00:02:29,160 --> 00:02:26,440 up to exploration these giant outer 34 00:02:33,630 --> 00:02:29,170 planets which are spheres of rotating 35 00:02:36,300 --> 00:02:33,640 fluid gas surrounded by 57 moons totally 36 00:02:38,520 --> 00:02:36,310 each planet has a unique ring system and 37 00:02:40,440 --> 00:02:38,530 they have magnetic fields which were 38 00:02:43,410 --> 00:02:40,450 immense compared to the magnetic field 39 00:02:53,390 --> 00:02:43,420 of Earth voyagers job was to explore 40 00:02:58,290 --> 00:02:55,380 scientists at Cape Canaveral Florida 41 00:03:00,570 --> 00:02:58,300 sent another unmanned Voyager spacecraft 42 00:03:03,479 --> 00:03:00,580 on its way to Jupiter and Saturn today 43 00:03:05,400 --> 00:03:03,489 it lifted off flawlessly at 8:56 a.m. 44 00:03:07,740 --> 00:03:05,410 and had none of the problems of the 45 00:03:09,630 --> 00:03:07,750 Voyager launched two weeks ago this 46 00:03:14,430 --> 00:03:09,640 voyager presumably will get to Jupiter 47 00:03:15,350 --> 00:03:14,440 in March of 1979 Lord you're too scared 48 00:03:19,259 --> 00:03:15,360 us 49 00:03:22,830 --> 00:03:19,269 Voyager 2 had problems in separating 50 00:03:26,580 --> 00:03:22,840 from the solid rocket kick stage the 51 00:03:28,830 --> 00:03:26,590 spacecraft today you know have a few 52 00:03:31,470 --> 00:03:28,840 problems but most of these problems were 53 00:03:34,320 --> 00:03:31,480 problems we experienced early on there 54 00:03:39,539 --> 00:03:34,330 was the the Voyager 2 spacecraft has a 55 00:03:41,850 --> 00:03:39,549 failed receiver and and a sick backup 56 00:03:45,760 --> 00:03:41,860 receiver that's the most serious problem 57 00:03:51,820 --> 00:03:48,430 the way we communicate with the with the 58 00:03:54,460 --> 00:03:51,830 Voyager spacecraft is that we send 59 00:03:56,560 --> 00:03:54,470 commands to the spacecraft series of 60 00:03:57,880 --> 00:03:56,570 digital bits and computer language that 61 00:03:59,500 --> 00:03:57,890 go to the spacecraft and it's the 62 00:04:03,100 --> 00:03:59,510 language that the spacecraft understand 63 00:04:06,370 --> 00:04:03,110 understands these bits are transmitted 64 00:04:07,840 --> 00:04:06,380 and from ground stations located around 65 00:04:10,480 --> 00:04:07,850 the earth what we call the Deep Space 66 00:04:12,940 --> 00:04:10,490 Network the three deep space network 67 00:04:16,560 --> 00:04:12,950 stations are located in Goldstone 68 00:04:19,540 --> 00:04:16,570 California outside of Madrid Spain and 69 00:04:22,240 --> 00:04:19,550 outside of Canberra Australia as the 70 00:04:24,070 --> 00:04:22,250 Earth turns we can maintain Kamiya 71 00:04:27,550 --> 00:04:24,080 continuous communication with the point 72 00:04:29,080 --> 00:04:27,560 in space the spacecraft in turn there's 73 00:04:30,610 --> 00:04:29,090 kind of the reverse link coming back 74 00:04:33,190 --> 00:04:30,620 down the information that the spacecraft 75 00:04:34,870 --> 00:04:33,200 gathers goes into a transmitter on the 76 00:04:36,130 --> 00:04:34,880 spacecraft it's transmitted into those 77 00:04:37,900 --> 00:04:36,140 big ears and the ground of the deep 78 00:04:40,120 --> 00:04:37,910 space network and transmitted back then 79 00:04:42,460 --> 00:04:40,130 on the ground to our control facility 80 00:04:45,490 --> 00:04:42,470 here in Pasadena the transmitter on 81 00:04:48,990 --> 00:04:45,500 Voyager is like tens of watts it's like 82 00:04:52,790 --> 00:04:49,000 20 watts less power than an average 83 00:04:55,830 --> 00:04:52,800 light bulb on your front porch 84 00:04:59,429 --> 00:04:55,840 on the other hand when that signal is 85 00:05:03,179 --> 00:04:59,439 received on the earth it is literally a 86 00:05:05,749 --> 00:05:03,189 tiny tiny fraction of a watt that has 87 00:05:09,450 --> 00:05:05,759 received the amount of power received by 88 00:05:12,300 --> 00:05:09,460 the ground antennas is something like a 89 00:05:20,690 --> 00:05:12,310 billion of the amount of power used by 90 00:05:24,870 --> 00:05:23,370 man is known about the planet Jupiter 91 00:05:26,730 --> 00:05:24,880 ever since he took a good look at the 92 00:05:28,470 --> 00:05:26,740 night sky it's not what you'd call a 93 00:05:30,840 --> 00:05:28,480 near neighbor though being more than 94 00:05:32,640 --> 00:05:30,850 four hundred million miles away but 95 00:05:37,140 --> 00:05:32,650 after all these centuries were getting a 96 00:05:39,210 --> 00:05:37,150 closer look than we've ever had when 97 00:05:42,060 --> 00:05:39,220 Voyager got up close and we looked at 98 00:05:44,580 --> 00:05:42,070 the time-lapse movies of the atmosphere 99 00:05:47,700 --> 00:05:44,590 in motion things were changing every day 100 00:05:50,180 --> 00:05:47,710 little storms would pop up out of 101 00:05:53,820 --> 00:05:50,190 nowhere and they'd get ripped apart 102 00:05:56,730 --> 00:05:53,830 dispersed all in a day or two and that 103 00:05:59,730 --> 00:05:56,740 made the mystery of the Great Red Spot 104 00:06:04,410 --> 00:05:59,740 and all those other large spots even 105 00:06:07,380 --> 00:06:04,420 deeper because how could they last for 106 00:06:10,430 --> 00:06:07,390 so long in the midst of all that chaotic 107 00:06:13,170 --> 00:06:10,440 motion it was a startling discovery as 108 00:06:15,870 --> 00:06:13,180 Voyager approached Jupiter the first 109 00:06:17,310 --> 00:06:15,880 thing that inter intercepted was what's 110 00:06:19,470 --> 00:06:17,320 called the bow shock that's a shock 111 00:06:22,200 --> 00:06:19,480 where the supersonic solar wind becomes 112 00:06:23,730 --> 00:06:22,210 subsonic and that shock the solar wind 113 00:06:26,430 --> 00:06:23,740 velocity which is a million miles per 114 00:06:28,320 --> 00:06:26,440 hour abruptly decreases to 250,000 miles 115 00:06:32,430 --> 00:06:28,330 per hour that abrupt change in velocity 116 00:06:34,890 --> 00:06:32,440 causes the ionized gas to vibrate and we 117 00:06:36,750 --> 00:06:34,900 can sense we can hear the shock and we 118 00:06:39,030 --> 00:06:36,760 can hear the vibrations associated with 119 00:06:40,740 --> 00:06:39,040 that shock as a spacecraft flew through 120 00:06:43,110 --> 00:06:40,750 the shock itself 121 00:06:46,470 --> 00:06:43,120 we had expected that the magnetic field 122 00:06:49,260 --> 00:06:46,480 might expend something like a million 123 00:06:50,940 --> 00:06:49,270 miles or so from the planet in fact it 124 00:06:52,650 --> 00:06:50,950 extends some three to four million miles 125 00:06:55,890 --> 00:06:52,660 from the planet now we understand 126 00:06:58,260 --> 00:06:55,900 because IO is injecting into the 127 00:07:00,870 --> 00:06:58,270 magnetic field some 1 to 2 tons of 128 00:07:03,630 --> 00:07:00,880 material every second that material as 129 00:07:05,520 --> 00:07:03,640 it spins with Jupiter is centrally 130 00:07:07,770 --> 00:07:05,530 expanding Jupiter's magnetic field 131 00:07:13,230 --> 00:07:07,780 inflating it to a much larger size than 132 00:07:16,530 --> 00:07:13,240 it would normally be we expected quite 133 00:07:18,680 --> 00:07:16,540 frankly the satellites of the outer 134 00:07:21,630 --> 00:07:18,690 solar system to be quite bland and 135 00:07:24,510 --> 00:07:21,640 geologically lifeless is we've flew 136 00:07:26,340 --> 00:07:24,520 closer I look less and less like 137 00:07:29,070 --> 00:07:26,350 anything we've ever seen the impact 138 00:07:33,030 --> 00:07:29,080 craters turned into a regular dark 139 00:07:35,430 --> 00:07:33,040 patterns and the colored patches red 140 00:07:38,310 --> 00:07:35,440 yellows painted on the surface as a 141 00:07:40,740 --> 00:07:38,320 matter of fact as we flew closer we saw 142 00:07:44,940 --> 00:07:40,750 nothing at all that resembled an impact 143 00:07:48,450 --> 00:07:44,950 crater if Voyager 1 discovered 11 active 144 00:07:50,190 --> 00:07:48,460 volcanoes and 9 of those were still 145 00:07:53,820 --> 00:07:50,200 active when Voyager 2 returned four 146 00:07:55,650 --> 00:07:53,830 months later I think the the event in 147 00:07:58,290 --> 00:07:55,660 the end the omission which really 148 00:07:59,190 --> 00:07:58,300 altered our view and our expectation for 149 00:08:02,040 --> 00:07:59,200 the rest of the mission was the 150 00:08:04,650 --> 00:08:02,050 discovery of the volcanoes an isle that 151 00:08:07,110 --> 00:08:04,660 was such a dramatic and unexpected thing 152 00:08:08,760 --> 00:08:07,120 to find that it really told us that we 153 00:08:11,310 --> 00:08:08,770 could no longer be complacent we could 154 00:08:13,080 --> 00:08:11,320 no longer expect to understand or 155 00:08:19,830 --> 00:08:13,090 anticipate what we were really going to 156 00:08:22,380 --> 00:08:19,840 see Voyager 1 flew in close to Isle for 157 00:08:26,850 --> 00:08:22,390 a close up flyby of IO to give good 158 00:08:29,510 --> 00:08:26,860 return from Isle and made its close 159 00:08:32,279 --> 00:08:29,520 encounters with the Galilean satellites 160 00:08:35,610 --> 00:08:32,289 after the closest approach of Jupiter 161 00:08:37,409 --> 00:08:35,620 if we look at Callisto it's one of the 162 00:08:40,680 --> 00:08:37,419 most heavily cratered objects in the 163 00:08:44,610 --> 00:08:40,690 solar saturated with impact craters when 164 00:08:46,770 --> 00:08:44,620 we looked at Ganymede we find two kinds 165 00:08:49,490 --> 00:08:46,780 of terrains one is a terrain looks very 166 00:08:51,740 --> 00:08:49,500 much like Callisto but in addition 167 00:08:56,030 --> 00:08:51,750 Ganymede has a 168 00:08:59,690 --> 00:08:56,040 very complex intercepting network of 169 00:09:01,970 --> 00:08:59,700 faults in a younger terrain which has 170 00:09:03,800 --> 00:09:01,980 evidently welled up from the interior 171 00:09:06,170 --> 00:09:03,810 and replaced these this old cratered 172 00:09:09,700 --> 00:09:06,180 terrain is so similar to crystal the 173 00:09:13,070 --> 00:09:09,710 case of Europa we see yet another style 174 00:09:16,880 --> 00:09:13,080 we see gargantuan fault patterns in 175 00:09:20,210 --> 00:09:16,890 which this ocean has frozen repeatedly 176 00:09:22,550 --> 00:09:20,220 broken open and fluids float up to the 177 00:09:24,620 --> 00:09:22,560 surface producing dark puddles of 178 00:09:27,340 --> 00:09:24,630 material within the faults these are 179 00:09:30,440 --> 00:09:27,350 then broken again so there's 180 00:09:32,840 --> 00:09:30,450 intersecting and cross-cutting networks 181 00:09:37,040 --> 00:09:32,850 there were two small satellites 182 00:09:39,950 --> 00:09:37,050 discovered at Jupiter one of them found 183 00:09:42,200 --> 00:09:39,960 orbiting just outside a very thin 184 00:09:45,080 --> 00:09:42,210 tenuous ring of material that was 185 00:09:49,790 --> 00:09:45,090 discovered the Jupiter the imaging team 186 00:09:51,830 --> 00:09:49,800 members planned one single photo an 11 187 00:09:54,290 --> 00:09:51,840 minute exposure that would be taken as 188 00:09:57,890 --> 00:09:54,300 the spacecraft plunged through the 189 00:09:59,380 --> 00:09:57,900 equator plane of Jupiter and it just so 190 00:10:02,170 --> 00:09:59,390 happened that there was a ring there 191 00:10:04,200 --> 00:10:02,180 it's dusty 192 00:10:09,070 --> 00:10:04,210 there it seems to be no indication of 193 00:10:17,650 --> 00:10:09,080 water or ice within the ring so it's 194 00:10:19,780 --> 00:10:17,660 probably a minute of rocky material an 195 00:10:21,910 --> 00:10:19,790 outerspace spectacular that was the 196 00:10:24,250 --> 00:10:21,920 stuff of dreams only a generation ago 197 00:10:26,769 --> 00:10:24,260 began snapping into the sharp focus of 198 00:10:28,570 --> 00:10:26,779 reality today after its billion mile 199 00:10:30,760 --> 00:10:28,580 journey from Earth to Voyager 1 200 00:10:32,590 --> 00:10:30,770 spacecraft sent back pictures of man's 201 00:10:33,550 --> 00:10:32,600 closest look yet at the ringed planet 202 00:10:35,949 --> 00:10:33,560 Saturn 203 00:10:37,780 --> 00:10:35,959 the closest encounter of spacecraft and 204 00:10:41,260 --> 00:10:37,790 planet occurs later tonight when Voyager 205 00:10:43,810 --> 00:10:41,270 sails just 77,000 miles from Saturn's 206 00:10:46,150 --> 00:10:43,820 yellow clouds but already one scientist 207 00:10:48,900 --> 00:10:46,160 said in the strange world of Saturn's 208 00:10:52,000 --> 00:10:48,910 rings the bizarre has become commonplace 209 00:10:54,449 --> 00:10:52,010 the closer that Voyager got to Saturn 210 00:10:56,710 --> 00:10:54,459 the more and more detail and structure 211 00:10:58,900 --> 00:10:56,720 Saturn's rings turned out to have and 212 00:11:01,210 --> 00:10:58,910 this just was an enormous surprise to 213 00:11:03,750 --> 00:11:01,220 everybody the Rings were simultaneously 214 00:11:05,800 --> 00:11:03,760 breathtaking but completely baffling and 215 00:11:08,380 --> 00:11:05,810 there was just far more structure than 216 00:11:10,510 --> 00:11:08,390 people had anticipated not only did we 217 00:11:12,880 --> 00:11:10,520 find many many concentric features 218 00:11:16,210 --> 00:11:12,890 within the Rings but we found eccentric 219 00:11:18,850 --> 00:11:16,220 rings we found that the F frame which 220 00:11:21,370 --> 00:11:18,860 had been discovered by pioneer had 221 00:11:22,750 --> 00:11:21,380 braids in it and kinks and clumps all 222 00:11:24,760 --> 00:11:22,760 these things no one had ever even 223 00:11:27,340 --> 00:11:24,770 dreamed about before Voyager got to 224 00:11:31,840 --> 00:11:29,230 and then of course they were the spokes 225 00:11:34,330 --> 00:11:31,850 that Voyager discovered about a month or 226 00:11:37,060 --> 00:11:34,340 month and a half before encounter and 227 00:11:39,280 --> 00:11:37,070 these are these radial features in the B 228 00:11:44,860 --> 00:11:39,290 ring that come and go they are seen 229 00:11:47,830 --> 00:11:44,870 orbiting around the Rings and no one had 230 00:11:49,390 --> 00:11:47,840 a clue or at least not a yeah not a 231 00:11:51,040 --> 00:11:49,400 reasonable clue in the beginning as to 232 00:11:54,010 --> 00:11:51,050 what caused these features or even what 233 00:11:55,990 --> 00:11:54,020 they were that if you look at the rings 234 00:11:58,540 --> 00:11:56,000 of Saturn it for a period of time and 235 00:12:00,670 --> 00:11:58,550 watch the spokes go around and round and 236 00:12:03,190 --> 00:12:00,680 you examined the appearance of the 237 00:12:05,620 --> 00:12:03,200 spokes on the Rings that appearance 238 00:12:10,000 --> 00:12:05,630 changes and it changes with a period 239 00:12:13,480 --> 00:12:10,010 that is equal to the period of the spin 240 00:12:15,010 --> 00:12:13,490 of Saturn's magnetic field voyager found 241 00:12:17,620 --> 00:12:15,020 that Saturn's the magnetic field as 242 00:12:19,120 --> 00:12:17,630 pioneer 11 had already told us is is 243 00:12:20,800 --> 00:12:19,130 weaker that is it's only about 244 00:12:23,020 --> 00:12:20,810 one-twentieth the strength of Jupiter's 245 00:12:24,520 --> 00:12:23,030 magnetic field that means it's magnetic 246 00:12:26,050 --> 00:12:24,530 field doesn't extend as far from the 247 00:12:26,620 --> 00:12:26,060 planet about a million miles from the 248 00:12:29,290 --> 00:12:26,630 planet 249 00:12:31,270 --> 00:12:29,300 what Voyager discovered was how rapidly 250 00:12:32,920 --> 00:12:31,280 that magnetic field was rotating the 251 00:12:35,860 --> 00:12:32,930 magnetic field of Jupiter rotates with a 252 00:12:37,660 --> 00:12:35,870 period just under ten hours at Saturn it 253 00:12:39,460 --> 00:12:37,670 turns out the magnetic field rotates 254 00:12:41,050 --> 00:12:39,470 with a period of about 10 hours and 40 255 00:12:45,220 --> 00:12:41,060 minutes so this was the first measure of 256 00:12:48,630 --> 00:12:45,230 the length of the day on Saturn turns 257 00:12:51,700 --> 00:12:48,640 out when we finally measured the 258 00:12:53,860 --> 00:12:51,710 magnetic field and the radio emissions 259 00:12:57,820 --> 00:12:53,870 that are tied to the magnetic field that 260 00:13:01,390 --> 00:12:57,830 the inside of Saturn is moving quite 261 00:13:04,710 --> 00:13:01,400 slowly it's moving more slowly than most 262 00:13:07,270 --> 00:13:04,720 of the storms in the atmosphere and that 263 00:13:10,990 --> 00:13:07,280 the difference in those speeds 264 00:13:13,270 --> 00:13:11,000 translates to 500 meters per second for 265 00:13:14,590 --> 00:13:13,280 the winds which is over a thousand miles 266 00:13:17,950 --> 00:13:14,600 an hour 267 00:13:21,160 --> 00:13:17,960 and that made Saturn a lot windier 268 00:13:23,680 --> 00:13:21,170 planet than Jupiter that was the big 269 00:13:26,010 --> 00:13:23,690 surprise for me and we went Voyager got 270 00:13:34,300 --> 00:13:30,790 Voyager 1 approached Saturn in such a 271 00:13:36,460 --> 00:13:34,310 way that it flew past Titan before its 272 00:13:39,220 --> 00:13:36,470 closest approach to Saturn that 273 00:13:42,790 --> 00:13:39,230 trajectory then because of the tilt of 274 00:13:46,510 --> 00:13:42,800 the satellite system around Saturn 275 00:13:49,660 --> 00:13:46,520 caused the spacecraft to fly low 276 00:13:52,450 --> 00:13:49,670 initially and then get deflected as it 277 00:13:54,790 --> 00:13:52,460 made its closest approach to Saturn 278 00:13:56,080 --> 00:13:54,800 going through the ring plane up out of 279 00:14:01,450 --> 00:13:56,090 the plane of the ecliptic 280 00:14:07,570 --> 00:14:01,460 we knew that Titan had an atmosphere we 281 00:14:10,900 --> 00:14:07,580 had no idea how deep it was or what it 282 00:14:14,310 --> 00:14:10,910 was made out of and what Voyager found 283 00:14:18,760 --> 00:14:14,320 was a nitrogen atmosphere with traces of 284 00:14:20,980 --> 00:14:18,770 methane and other hydrocarbons and it 285 00:14:23,230 --> 00:14:20,990 was turned out to be quite a batma 286 00:14:25,750 --> 00:14:23,240 sphere we suspect there might be an 287 00:14:28,750 --> 00:14:25,760 ocean of material called ethane 288 00:14:31,810 --> 00:14:28,760 there could be all kinds of complicated 289 00:14:34,420 --> 00:14:31,820 hydrocarbons of different colors and 290 00:14:37,990 --> 00:14:34,430 different states some ices some fluids 291 00:14:41,530 --> 00:14:38,000 there's all manner of hallucination 292 00:14:43,080 --> 00:14:41,540 about hydrocarbon goop that rains out of 293 00:14:45,820 --> 00:14:43,090 the atmosphere and falls on the surface 294 00:14:47,640 --> 00:14:45,830 as matter of fact Titan remains one of 295 00:14:52,170 --> 00:14:47,650 the really exciting challenges for 296 00:14:55,330 --> 00:14:52,180 future future exploration in the case of 297 00:14:59,160 --> 00:14:55,340 limas we see a crater on - that's about 298 00:15:02,260 --> 00:14:59,170 40% of its diameter a little larger and 299 00:15:06,010 --> 00:15:02,270 that would have been enough to shatter 300 00:15:07,180 --> 00:15:06,020 the object and of course we wouldn't see 301 00:15:10,200 --> 00:15:07,190 the crater then because it would really 302 00:15:12,490 --> 00:15:10,210 like a kind of a giant ball of sand and 303 00:15:14,680 --> 00:15:12,500 in the case of Tethys there's another 304 00:15:15,320 --> 00:15:14,690 very large crater even larger than the 305 00:15:19,430 --> 00:15:15,330 one on 306 00:15:22,460 --> 00:15:19,440 - but in that case notice the floor has 307 00:15:26,240 --> 00:15:22,470 is now rounded out so that it is curved 308 00:15:28,250 --> 00:15:26,250 as the rest of the object slain is the 309 00:15:31,670 --> 00:15:28,260 case of Diana you'll notice that most of 310 00:15:33,380 --> 00:15:31,680 the surface is pretty bland and only in 311 00:15:37,730 --> 00:15:33,390 this one region near the trailing 312 00:15:39,470 --> 00:15:37,740 hemisphere do we see a lot of detail on 313 00:15:42,079 --> 00:15:39,480 the surface here we see a lot of Criss 314 00:15:44,920 --> 00:15:42,089 crossing faults with wispy bright 315 00:15:47,720 --> 00:15:44,930 markings around them finally we look at 316 00:15:50,750 --> 00:15:47,730 Enceladus we're talking about very cold 317 00:15:54,079 --> 00:15:50,760 regions and here we are with this little 318 00:15:56,600 --> 00:15:54,089 tiny object showing geologic activity of 319 00:15:59,269 --> 00:15:56,610 the scale that Enceladus does in which 320 00:16:02,180 --> 00:15:59,279 the ancient cratered terrain has been 321 00:16:04,880 --> 00:16:02,190 broken and has collapsed into the 322 00:16:08,650 --> 00:16:04,890 interior fluids have flowed out into 323 00:16:17,090 --> 00:16:08,660 those open gashes in the crust 324 00:16:20,569 --> 00:16:17,100 repeatedly well after we got Voyager 1 325 00:16:23,690 --> 00:16:20,579 to Saturn we went back to NASA and said 326 00:16:26,030 --> 00:16:23,700 we have now satisfied all of the 327 00:16:29,139 --> 00:16:26,040 objectives for the MJS for the Voyager 328 00:16:32,480 --> 00:16:29,149 mission how about giving us money and 329 00:16:35,030 --> 00:16:32,490 giving us permission to target Voyager 330 00:16:37,400 --> 00:16:35,040 to tweak its trajectory just a little 331 00:16:41,000 --> 00:16:37,410 bit so that we can go on to Uranus it 332 00:16:42,270 --> 00:16:41,010 was a penalty for this the data that we 333 00:16:44,670 --> 00:16:42,280 got 334 00:16:47,580 --> 00:16:44,680 the quality of the mission at Saturn was 335 00:16:49,680 --> 00:16:47,590 a little bit less if we targeted for 336 00:16:52,620 --> 00:16:49,690 Uranus and it would be if we optimized 337 00:16:56,370 --> 00:16:52,630 percent and we bared all those facts to 338 00:16:58,140 --> 00:16:56,380 NASA we told them that it was maybe a 60 339 00:16:59,640 --> 00:16:58,150 70 percent chance but we thought it was 340 00:17:01,760 --> 00:16:59,650 worth it and I guess we were pretty 341 00:17:04,500 --> 00:17:01,770 persuasive because they bought the idea 342 00:17:07,620 --> 00:17:04,510 soon after Voyager twos closest approach 343 00:17:11,790 --> 00:17:07,630 to Saturn in fact while it was behind 344 00:17:14,970 --> 00:17:11,800 the planet its scan platform got stuck 345 00:17:18,600 --> 00:17:14,980 at a mechanical failure and we weren't 346 00:17:20,120 --> 00:17:18,610 able to aim the cameras and the other 347 00:17:24,540 --> 00:17:20,130 pointable instruments on the spacecraft 348 00:17:27,929 --> 00:17:24,550 at the targets after several years we 349 00:17:31,110 --> 00:17:27,939 concluded that in fact during the Saturn 350 00:17:36,240 --> 00:17:31,120 encounter we had moved this platform too 351 00:17:40,440 --> 00:17:36,250 much too fast and that if we used the 352 00:17:43,920 --> 00:17:40,450 platform in a consistently slow at a 353 00:17:46,920 --> 00:17:43,930 slower rate and if we constrained the 354 00:17:49,530 --> 00:17:46,930 total amount of angular motion that we 355 00:17:57,080 --> 00:17:49,540 applied to the platform then in fact we 356 00:18:02,220 --> 00:18:00,570 Voyageur to the amazing robot spacecraft 357 00:18:05,070 --> 00:18:02,230 that was launched eight and a half years 358 00:18:07,050 --> 00:18:05,080 ago and just kept on going past yet 359 00:18:09,420 --> 00:18:07,060 another milestone today as it became the 360 00:18:13,320 --> 00:18:09,430 first spacecraft to fly past the planet 361 00:18:16,320 --> 00:18:13,330 Uranus Uranus is not a very photogenic 362 00:18:20,550 --> 00:18:16,330 place it looks more or less like a big 363 00:18:22,470 --> 00:18:20,560 blue ping-pong ball but we did see 364 00:18:23,910 --> 00:18:22,480 clouds in the atmosphere of Uranus and 365 00:18:29,310 --> 00:18:23,920 they did tell us something 366 00:18:34,200 --> 00:18:29,320 in fact Uranus is a tipped-over version 367 00:18:36,210 --> 00:18:34,210 of Jupiter and Saturn the cloud patterns 368 00:18:38,820 --> 00:18:36,220 are more muted but they have the same 369 00:18:41,460 --> 00:18:38,830 kind of banded structure that Jupiter 370 00:18:43,800 --> 00:18:41,470 and Saturn have now what that says is 371 00:18:48,750 --> 00:18:43,810 that the spin of a planet is the 372 00:18:51,840 --> 00:18:48,760 all-important process or thing that 373 00:18:53,250 --> 00:18:51,850 organizes whether Uranus is a very 374 00:18:56,370 --> 00:18:53,260 peculiar plant in the sense it's tipped 375 00:18:58,910 --> 00:18:56,380 on its side right now with the south 376 00:19:01,500 --> 00:18:58,920 polar region headed pointed at the Sun 377 00:19:03,900 --> 00:19:01,510 we had expected that the magnetic field 378 00:19:05,400 --> 00:19:03,910 pole would also be up near the 379 00:19:06,780 --> 00:19:05,410 rotational axis so the magnetic field 380 00:19:09,540 --> 00:19:06,790 would be tipped on its side what we 381 00:19:11,070 --> 00:19:09,550 found was to everyone's surprise that 382 00:19:13,560 --> 00:19:11,080 the magnetic field rather than being 383 00:19:16,020 --> 00:19:13,570 pointed at the Sun was tilted some 60 384 00:19:17,460 --> 00:19:16,030 degrees from the rotation axis not only 385 00:19:19,140 --> 00:19:17,470 that but the center of the magnetic 386 00:19:21,510 --> 00:19:19,150 field was displaced from the center of 387 00:19:23,910 --> 00:19:21,520 the planet by almost a third of the 388 00:19:27,570 --> 00:19:23,920 radius of the planet Uranus is magnetic 389 00:19:31,620 --> 00:19:27,580 field is a bit stronger than that on on 390 00:19:34,860 --> 00:19:31,630 Saturn and it extends some 300,000 miles 391 00:19:36,210 --> 00:19:34,870 from the planet the rotation period that 392 00:19:37,800 --> 00:19:36,220 is the length of the day on you and this 393 00:19:40,770 --> 00:19:37,810 is measured by how rapidly the magnetic 394 00:19:43,890 --> 00:19:40,780 field rotating is about 17 and a quarter 395 00:19:45,660 --> 00:19:43,900 hours the big problem going on to Uranus 396 00:19:48,420 --> 00:19:45,670 is that it's twice as far away from the 397 00:19:50,730 --> 00:19:48,430 earth as Saturn is in order to 398 00:19:56,190 --> 00:19:50,740 compensate for the the darker 399 00:19:59,370 --> 00:19:56,200 environment we had to make sure that the 400 00:20:01,500 --> 00:19:59,380 spacecraft would be steadier and to make 401 00:20:03,660 --> 00:20:01,510 the spacecraft steadier we had to deal 402 00:20:05,010 --> 00:20:03,670 with the things that made the spacecraft 403 00:20:07,200 --> 00:20:05,020 move well 404 00:20:09,690 --> 00:20:07,210 flying through space the Iranian rings 405 00:20:15,780 --> 00:20:09,700 are inherently dark in fact they are no 406 00:20:17,790 --> 00:20:15,790 brighter than coal dust so imagine 407 00:20:19,650 --> 00:20:17,800 trying to take an image of coal dust at 408 00:20:26,070 --> 00:20:19,660 Twilight but it's even worse than that 409 00:20:30,510 --> 00:20:26,080 so we had to worry about the necessity 410 00:20:33,750 --> 00:20:30,520 of using long exposures and the fact 411 00:20:35,760 --> 00:20:33,760 that the spacecraft scan platform is not 412 00:20:38,520 --> 00:20:35,770 a stable platform and always move 413 00:20:41,370 --> 00:20:38,530 someone best image that we got in fact 414 00:20:43,830 --> 00:20:41,380 of the Iranian ring system we had to use 415 00:20:49,370 --> 00:20:43,840 image motion compensation what we saw in 416 00:20:51,390 --> 00:20:49,380 that image is a sheet of dust that 417 00:20:54,630 --> 00:20:51,400 extends throughout the iranian ring 418 00:20:57,450 --> 00:20:54,640 system and this sheet of dust is 419 00:21:00,270 --> 00:20:57,460 punctuated by by features many of them 420 00:21:03,570 --> 00:21:00,280 there are more features in that picture 421 00:21:05,730 --> 00:21:03,580 than there are rings seen from inbound 422 00:21:08,130 --> 00:21:05,740 so we have nine narrow rings seen in the 423 00:21:11,910 --> 00:21:08,140 inbound images and one newly discovered 424 00:21:13,590 --> 00:21:11,920 one the lambda ring as a matter of fact 425 00:21:16,320 --> 00:21:13,600 if we had our choice we never would have 426 00:21:20,280 --> 00:21:16,330 gone close to Miranda in order to get to 427 00:21:24,060 --> 00:21:20,290 Neptune we were obliged to go a 428 00:21:25,590 --> 00:21:24,070 particular distance from Uranus in order 429 00:21:27,450 --> 00:21:25,600 to get the right gravitational 430 00:21:29,970 --> 00:21:27,460 deflection on the spacecraft well turned 431 00:21:31,940 --> 00:21:29,980 out that that distance was exactly the 432 00:21:34,830 --> 00:21:31,950 distance that Miranda's orbit is from 433 00:21:37,650 --> 00:21:34,840 Uranus it is a very exotic and 434 00:21:41,100 --> 00:21:37,660 complicated place most of the regions 435 00:21:45,600 --> 00:21:41,110 that we viewed are heavily cratered cold 436 00:21:49,880 --> 00:21:45,610 rolling in chatterings but embedded in 437 00:21:53,190 --> 00:21:49,890 these are very unusual circular patches 438 00:21:54,900 --> 00:21:53,200 almost like racetracks of groove 439 00:21:58,260 --> 00:21:54,910 terrains that run around in circular 440 00:22:03,200 --> 00:21:58,270 bands surrounding very complicated Criss 441 00:22:09,659 --> 00:22:06,360 we address the the question what can we 442 00:22:11,519 --> 00:22:09,669 do to hear the data better we did come 443 00:22:15,440 --> 00:22:11,529 up with a technique called a rang where 444 00:22:17,880 --> 00:22:15,450 we took existing antennas and 445 00:22:20,100 --> 00:22:17,890 electronically wired them together so 446 00:22:23,909 --> 00:22:20,110 that in fact it had the appearance of 447 00:22:26,250 --> 00:22:23,919 being one larger antenna and we did that 448 00:22:30,690 --> 00:22:26,260 in Australia the primary receiving site 449 00:22:33,600 --> 00:22:30,700 at Uranus and combined the DSN stations 450 00:22:34,950 --> 00:22:33,610 with a borrowed antenna from the 451 00:22:42,950 --> 00:22:34,960 Australian radio at Radio Astronomy 452 00:22:46,860 --> 00:22:45,389 while we were moving from uranus and 453 00:22:48,240 --> 00:22:46,870 neptune on the ground we had two major 454 00:22:50,070 --> 00:22:48,250 things to do first of all we 455 00:22:52,860 --> 00:22:50,080 reprogrammed the software and board the 456 00:22:54,810 --> 00:22:52,870 spacecraft to do two things to stabilise 457 00:22:56,639 --> 00:22:54,820 the spacecraft so the pictures would not 458 00:22:58,200 --> 00:22:56,649 be smeared and to add some new 459 00:23:00,990 --> 00:22:58,210 techniques to the spacecraft it will 460 00:23:02,279 --> 00:23:01,000 allow it to pan and track the planet 461 00:23:04,470 --> 00:23:02,289 when we were taking pictures near the 462 00:23:07,200 --> 00:23:04,480 planet second thing we had to do is 463 00:23:09,029 --> 00:23:07,210 improve the communications capability we 464 00:23:10,889 --> 00:23:09,039 did that since the since neptune is 465 00:23:13,289 --> 00:23:10,899 twice as far away from the communication 466 00:23:15,120 --> 00:23:13,299 standpoint as uranus we did that by 467 00:23:17,430 --> 00:23:15,130 enlarging the size the antennas on the 468 00:23:19,710 --> 00:23:17,440 earth and by adding several new sets of 469 00:23:27,160 --> 00:23:19,720 antennas into our deep space network to 470 00:23:31,840 --> 00:23:29,830 it is mission accomplished for Voyager - 471 00:23:34,090 --> 00:23:31,850 the space probe is headed out of the 472 00:23:35,890 --> 00:23:34,100 solar system tonight after photographing 473 00:23:40,120 --> 00:23:35,900 parts of the universe no one had ever 474 00:23:42,970 --> 00:23:40,130 seen before now we had some hints from 475 00:23:46,780 --> 00:23:42,980 earth-based observations that Neptune 476 00:23:49,990 --> 00:23:46,790 had a few clouds and it was that was 477 00:23:52,900 --> 00:23:50,000 better than Uranus but we really weren't 478 00:23:56,520 --> 00:23:52,910 prepared for the spectacular weather 479 00:23:58,750 --> 00:23:56,530 activity that was found in fact 480 00:24:00,610 --> 00:23:58,760 Neptune's the windiest planet in the 481 00:24:07,000 --> 00:24:00,620 solar system and I was totally 482 00:24:09,940 --> 00:24:07,010 unprepared for that the winds are 325 483 00:24:13,450 --> 00:24:09,950 meters per second that's the speed that 484 00:24:16,930 --> 00:24:13,460 the great dark spot is moving relative 485 00:24:18,520 --> 00:24:16,940 to the inside of Neptune everything's 486 00:24:21,000 --> 00:24:18,530 going to the east but the great dark 487 00:24:24,820 --> 00:24:21,010 spot is going more slowly to the east 488 00:24:27,580 --> 00:24:24,830 than the inside of mention we had 489 00:24:29,440 --> 00:24:27,590 expected because Neptune does is not 490 00:24:31,570 --> 00:24:29,450 tipped on its side as a planet but is an 491 00:24:33,760 --> 00:24:31,580 upright planet that the magnetic field 492 00:24:36,130 --> 00:24:33,770 acts with axis would be aligned with the 493 00:24:37,930 --> 00:24:36,140 rotation axis that is the poles would be 494 00:24:40,180 --> 00:24:37,940 near the rotational pole we were 495 00:24:42,640 --> 00:24:40,190 surprised again the magnetic field is 496 00:24:44,560 --> 00:24:42,650 tilted by 47 degrees in the case of 497 00:24:46,750 --> 00:24:44,570 Neptune and it's center of the magnetic 498 00:24:49,630 --> 00:24:46,760 field is offset by almost two-thirds of 499 00:24:51,460 --> 00:24:49,640 the radius of the planet its magnetic 500 00:24:53,650 --> 00:24:51,470 field is somewhat weaker only about half 501 00:24:56,230 --> 00:24:53,660 of that of Saturn's for instance at the 502 00:24:58,360 --> 00:24:56,240 surface and its magnetic field extends 503 00:25:00,910 --> 00:24:58,370 only about 400,000 miles from its 504 00:25:04,270 --> 00:25:00,920 surface we did discover that the 505 00:25:07,810 --> 00:25:04,280 rotation period of the magnetic field is 506 00:25:10,360 --> 00:25:07,820 about 16 and hours and 7 minutes faster 507 00:25:17,610 --> 00:25:10,370 than Uranus but slower than both Cupit 508 00:25:24,880 --> 00:25:23,710 yes I'd like to report the scam as we 509 00:25:26,170 --> 00:25:24,890 approach Neptune we were approaching 510 00:25:28,000 --> 00:25:26,180 with the Sun and the earth almost 511 00:25:30,430 --> 00:25:28,010 directly behind us so you can see we're 512 00:25:32,710 --> 00:25:30,440 virtually a full disk of Neptune and we 513 00:25:35,530 --> 00:25:32,720 aimed to go right over the North Pole 514 00:25:37,600 --> 00:25:35,540 right up over the top of Neptune very 515 00:25:40,600 --> 00:25:37,610 very close to Neptune the trajectory is 516 00:25:43,270 --> 00:25:40,610 then bent by gravity moved south and we 517 00:25:47,590 --> 00:25:43,280 intercepted Triton while it was behind 518 00:25:50,590 --> 00:25:47,600 the up tun and underneath it well as we 519 00:25:54,400 --> 00:25:50,600 got closer and closer to Triton it got 520 00:25:55,720 --> 00:25:54,410 smaller and smaller and smaller and at 521 00:25:57,400 --> 00:25:55,730 the same time brighter and brighter 522 00:25:59,770 --> 00:25:57,410 turned out to be the brightest thing 523 00:26:02,140 --> 00:25:59,780 we've seen in the solar system north of 524 00:26:04,240 --> 00:26:02,150 the polar cap in the North just above 525 00:26:09,250 --> 00:26:04,250 the equator we find one thing we call 526 00:26:15,040 --> 00:26:09,260 the cantaloupe terrain it has a system 527 00:26:17,590 --> 00:26:15,050 of criss-crossing ridges which produce a 528 00:26:20,620 --> 00:26:17,600 set of almost squarish to ovoid dimples 529 00:26:23,140 --> 00:26:20,630 throughout the surface now we're talking 530 00:26:25,390 --> 00:26:23,150 about a surface which is 37 degrees 531 00:26:28,110 --> 00:26:25,400 above absolute zero this is a coldest 532 00:26:30,880 --> 00:26:28,120 thing in the solar system by far even 533 00:26:35,800 --> 00:26:30,890 the cold atmospheres of things like 534 00:26:40,690 --> 00:26:35,810 Neptune are warmer it was unthinkable to 535 00:26:43,150 --> 00:26:40,700 find activity going on a planet whose 536 00:26:44,410 --> 00:26:43,160 surface temperature is that low I mean 537 00:26:47,230 --> 00:26:44,420 this is getting down a point with 538 00:26:50,680 --> 00:26:47,240 molecules stop it was about a month 539 00:26:56,020 --> 00:26:50,690 after the Reuter encounter that we were 540 00:26:59,830 --> 00:26:56,030 looking at stereo images way down in the 541 00:27:04,600 --> 00:26:59,840 southern most part of tritons polar cap 542 00:27:06,130 --> 00:27:04,610 and we saw most of the features lined up 543 00:27:09,910 --> 00:27:06,140 as if they were on a perfect sphere in 544 00:27:13,270 --> 00:27:09,920 fact the two best examples turn out to 545 00:27:15,970 --> 00:27:13,280 be active RUP shion's in which material 546 00:27:19,630 --> 00:27:15,980 is being blown from the surface in a 547 00:27:21,600 --> 00:27:19,640 vertical column to an altitude of 8 548 00:27:24,330 --> 00:27:21,610 kilometers roughly 5 miles 549 00:27:25,910 --> 00:27:24,340 Roger discovered six new moons at 550 00:27:28,880 --> 00:27:25,920 Neptune 551 00:27:33,740 --> 00:27:28,890 two of them were found in the ring our 552 00:27:37,180 --> 00:27:33,750 core ring system orbiting along two of 553 00:27:40,040 --> 00:27:37,190 the ring arcs so apparently shepherding 554 00:27:42,730 --> 00:27:40,050 the edges of those ring arcs in some way 555 00:27:46,960 --> 00:27:42,740 when we look at Neptune's ring system as 556 00:27:51,160 --> 00:27:46,970 we can see here in this mosaic we see 557 00:27:52,970 --> 00:27:51,170 three continuous rings quite easily 558 00:27:56,170 --> 00:27:52,980 there is an outer ring 559 00:27:59,180 --> 00:27:56,180 it's the ring in which in fact the three 560 00:28:01,910 --> 00:27:59,190 arcs are embedded there's an inner ring 561 00:28:05,300 --> 00:28:01,920 which at in high phase geometry appears 562 00:28:07,400 --> 00:28:05,310 brighter than the outer ring that tells 563 00:28:09,350 --> 00:28:07,410 us right away it's dusty dustier than 564 00:28:13,100 --> 00:28:09,360 the outer ring and then we see an inner 565 00:28:15,020 --> 00:28:13,110 more diffuse ring at something like 42 566 00:28:18,650 --> 00:28:15,030 thousand kilometers from the centre of 567 00:28:20,000 --> 00:28:18,660 this of the planet we believe now that 568 00:28:22,400 --> 00:28:20,010 we'll be able to communicate with 569 00:28:24,980 --> 00:28:22,410 Voyager essentially as long as it stays 570 00:28:25,430 --> 00:28:24,990 alive two things will probably stop its 571 00:28:27,170 --> 00:28:25,440 life 572 00:28:28,940 --> 00:28:27,180 first of all it has a power source on 573 00:28:33,220 --> 00:28:28,950 board which is a small nuclear power 574 00:28:37,760 --> 00:28:36,170 radioactive decay of plutonium which 575 00:28:40,280 --> 00:28:37,770 generates heat which in turn is 576 00:28:42,620 --> 00:28:40,290 converted into electricity in about 20 577 00:28:44,690 --> 00:28:42,630 to 25 years we expect to be low enough 578 00:28:46,460 --> 00:28:44,700 so that there's not enough power to keep 579 00:28:49,550 --> 00:28:46,470 the critical subsystems of the 580 00:28:51,650 --> 00:28:49,560 spacecraft operating or at about the 581 00:28:53,960 --> 00:28:51,660 same time we could possibly run out of 582 00:28:55,460 --> 00:28:53,970 attitude control fuel that's the fuel 583 00:28:57,140 --> 00:28:55,470 which goes to the little thrusters which 584 00:28:59,480 --> 00:28:57,150 keeps the spacecraft stabilized and 585 00:29:01,910 --> 00:28:59,490 pointed at the earth now between the 586 00:29:04,070 --> 00:29:01,920 stars is a dilute gas ionized gas 587 00:29:05,690 --> 00:29:04,080 filling interplay interstellar space 588 00:29:08,060 --> 00:29:05,700 it's called the interstellar medium 589 00:29:11,150 --> 00:29:08,070 each star blows a bubble in that 590 00:29:13,130 --> 00:29:11,160 interstellar gas our own Sun does that 591 00:29:15,200 --> 00:29:13,140 that bubble in the case of our Sun is 592 00:29:17,660 --> 00:29:15,210 called the heliosphere we don't know how 593 00:29:19,160 --> 00:29:17,670 large that bubble is it may be that the 594 00:29:21,560 --> 00:29:19,170 distance to the edge of the bubble 595 00:29:23,300 --> 00:29:21,570 called the heliopause is a hundred times 596 00:29:24,950 --> 00:29:23,310 the distance from the earth to the Sun 597 00:29:29,210 --> 00:29:24,960 that is three times further than it is 598 00:29:31,460 --> 00:29:29,220 out to Neptune in which case 25 years 599 00:29:33,080 --> 00:29:31,470 Voyager 1 which will at that point be a 600 00:29:35,210 --> 00:29:33,090 hundred and thirty times as far from the 601 00:29:36,140 --> 00:29:35,220 Sun as the earth could well be returning 602 00:29:39,250 --> 00:29:36,150 data from 603 00:29:41,960 --> 00:29:39,260 interstellar space for the first time 604 00:29:44,540 --> 00:29:41,970 there will be a part of earth which will 605 00:29:52,920 --> 00:29:44,550 roam essentially forever in the galaxy