1 00:00:01,840 --> 00:00:07,680 Speaker 1: Welcome to brain Stuff, a production of iHeartRadio. Hey brain Stuff, 2 00:00:07,720 --> 00:00:11,039 Speaker 1: Lauren Vogelbomb here with another classic episode of the podcast 3 00:00:11,080 --> 00:00:15,920 Speaker 1: for you. In this one, we talk about Saturn's breathtaking rings, 4 00:00:16,280 --> 00:00:19,680 Speaker 1: how they formed, and why we're actually really lucky to 5 00:00:19,680 --> 00:00:22,279 Speaker 1: be around to see them, because they won't exist for 6 00:00:22,400 --> 00:00:25,000 Speaker 1: very long on the cosmic scale. 7 00:00:26,880 --> 00:00:30,320 Speaker 2: Hey brain Stuff, Lauren vogelbomb Here, humanity exists at a 8 00:00:30,440 --> 00:00:33,280 Speaker 2: very special time in our Solar System's history, the era 9 00:00:33,400 --> 00:00:36,560 Speaker 2: of Saturn's rings. In the next one hundred million years, 10 00:00:36,640 --> 00:00:40,599 Speaker 2: Saturn's rings will completely disappear, and planetary scientists have realized 11 00:00:40,640 --> 00:00:44,479 Speaker 2: that it acquired those rings only very recently. During the 12 00:00:44,560 --> 00:00:47,960 Speaker 2: Cassini mission's final months at Saturn, the NASA spacecraft carried 13 00:00:47,960 --> 00:00:50,559 Speaker 2: out a series of daring orbits through the space between 14 00:00:50,680 --> 00:00:53,440 Speaker 2: the planet's cloud tops and innermost edge of its rings. 15 00:00:54,000 --> 00:00:56,960 Speaker 2: This so called Grand Finale signaled that the end was 16 00:00:57,080 --> 00:01:00,680 Speaker 2: nigh for the probe, and on September fifteenth to tenty seventeen, 17 00:01:00,920 --> 00:01:03,800 Speaker 2: it burned up in the gas giant's atmosphere, bringing a 18 00:01:03,840 --> 00:01:07,120 Speaker 2: spectacular thirteen years of science in Saturn's orbit to a 19 00:01:07,160 --> 00:01:11,039 Speaker 2: poignant close. The spacecraft was low on fuel and to 20 00:01:11,080 --> 00:01:14,360 Speaker 2: avoid an accidental crash into one of Saturn's potentially habitable moons. 21 00:01:14,600 --> 00:01:16,640 Speaker 2: NASA had long ago decided that the best way to 22 00:01:16,680 --> 00:01:18,400 Speaker 2: dispose of the mission was to burn it up in 23 00:01:18,480 --> 00:01:22,600 Speaker 2: Saturn's upper atmosphere. The agency wanted to avoid earthly contamination 24 00:01:22,760 --> 00:01:26,959 Speaker 2: on these pristine alien environments. Before its fiery death, however, 25 00:01:27,160 --> 00:01:30,919 Speaker 2: Cassini took unprecedented measurements of the mysterious ring gap region 26 00:01:30,959 --> 00:01:36,080 Speaker 2: to reveal some surprising ring dynamics. Though mission scientists expected 27 00:01:36,080 --> 00:01:39,120 Speaker 2: to detect some wispy elemental gases in this empty region, 28 00:01:39,400 --> 00:01:42,800 Speaker 2: Cassini's particle instrumentation found a smorgas board of elements and 29 00:01:42,840 --> 00:01:46,400 Speaker 2: molecules raining from the rings down to the planet's atmosphere. 30 00:01:46,920 --> 00:01:49,880 Speaker 2: They estimated around ten tons of material that's about nine 31 00:01:49,920 --> 00:01:54,320 Speaker 2: thousand kilos is falling onto Saturn from the rings per second. 32 00:01:55,120 --> 00:01:58,120 Speaker 2: That means that Saturn's rings will eventually disappear and will 33 00:01:58,120 --> 00:02:00,440 Speaker 2: have existed only for a short blip of s Saturn's 34 00:02:00,440 --> 00:02:04,680 Speaker 2: four billion year life span. So far, researchers have used 35 00:02:04,680 --> 00:02:08,560 Speaker 2: Cassini's ring dives to estimate when Saturn acquired its famous rings. 36 00:02:09,800 --> 00:02:12,840 Speaker 2: When Cassini zipped through Saturn's ring plane. Mission managers allowed 37 00:02:12,840 --> 00:02:16,080 Speaker 2: the planet, its rings and moons to gravitationally tug at 38 00:02:16,080 --> 00:02:20,200 Speaker 2: these speeding spacecraft. These extremely slight tugs resulted in tiny 39 00:02:20,280 --> 00:02:23,639 Speaker 2: changes in the probe's trajectory which could be precisely measured. 40 00:02:24,080 --> 00:02:27,280 Speaker 2: Those changes allowed scientists, too, for the first time, make 41 00:02:27,320 --> 00:02:29,800 Speaker 2: a very good measurement of how much mass is holed 42 00:02:29,880 --> 00:02:34,320 Speaker 2: up in Saturn's rings after analyzing the final set of orbits. However, 43 00:02:34,440 --> 00:02:37,640 Speaker 2: the extent to which Cassini's trajectory was deflected initially didn't 44 00:02:37,680 --> 00:02:41,040 Speaker 2: make sense. It didn't match the predictions by theoretical models. 45 00:02:41,480 --> 00:02:44,640 Speaker 2: It turned out the Cassini's motion was being additionally altered 46 00:02:44,680 --> 00:02:47,880 Speaker 2: by massive flows of material at Saturn's equator, inside its 47 00:02:47,919 --> 00:02:51,400 Speaker 2: thick atmosphere about six thousand miles or nearly ten thousand 48 00:02:51,480 --> 00:02:55,320 Speaker 2: kilometers deep. These massive flows are moving about four percent 49 00:02:55,440 --> 00:02:59,119 Speaker 2: slower than the visible upper atmospheric clouds, causing a gravitational 50 00:02:59,120 --> 00:03:03,520 Speaker 2: anomaly that was and predicted Cassini projects. Scientist Linda Spilker 51 00:03:03,520 --> 00:03:06,360 Speaker 2: of NASA's Jet Propulsion Laboratory said in a statement, the 52 00:03:06,400 --> 00:03:09,720 Speaker 2: discovery of deeply rotating layers is a surprising revelation about 53 00:03:09,720 --> 00:03:12,560 Speaker 2: the internal structure of the planet. The question is what 54 00:03:12,800 --> 00:03:15,440 Speaker 2: causes the more rapidly rotating part of the atmosphere to 55 00:03:15,480 --> 00:03:17,800 Speaker 2: go so deep, and what does that tell us about 56 00:03:17,800 --> 00:03:22,880 Speaker 2: Saturn's interior. However, with this anomaly partially explained, scientists were 57 00:03:22,880 --> 00:03:25,920 Speaker 2: free to measure the gravitational influence of Saturn's rings and 58 00:03:26,120 --> 00:03:29,520 Speaker 2: thus measure their mass. The researchers estimate that the total 59 00:03:29,560 --> 00:03:32,400 Speaker 2: mass of Saturn's rings is approximately forty percent that of 60 00:03:32,400 --> 00:03:36,280 Speaker 2: Saturn's moon Mimas. Considering Mimas is two thousand times smaller 61 00:03:36,320 --> 00:03:38,960 Speaker 2: than Earth's moon, there certainly isn't a lot of material 62 00:03:39,040 --> 00:03:43,320 Speaker 2: in Saturn's rings. Scientists had previously relied on density waves 63 00:03:43,400 --> 00:03:45,960 Speaker 2: or ripples through the rings caused by the motion of 64 00:03:45,960 --> 00:03:49,760 Speaker 2: these sixty two moons in Saturn's orbit to estimate ring mass. 65 00:03:50,280 --> 00:03:53,840 Speaker 2: Although these estimates were also low, astronomers have always assumed 66 00:03:53,920 --> 00:03:56,000 Speaker 2: there was some kind of hidden mass in large blocks 67 00:03:56,000 --> 00:03:59,840 Speaker 2: of material that remained unseen. Now, at the precision measurements 68 00:03:59,840 --> 00:04:02,360 Speaker 2: made by Cassini's final orbits, we know that there is 69 00:04:02,440 --> 00:04:05,120 Speaker 2: no hidden mass. The lower the mass of the rings, 70 00:04:05,320 --> 00:04:08,520 Speaker 2: the younger they are, and because they are predominantly made 71 00:04:08,520 --> 00:04:11,080 Speaker 2: of ice, if they were older, the ring material would 72 00:04:11,080 --> 00:04:15,800 Speaker 2: have become contaminated by interplanetary debris, dulling them, and Saturn's rings, 73 00:04:15,800 --> 00:04:19,680 Speaker 2: as we're acutely aware, are beautifully bright. Previous estimates of 74 00:04:19,760 --> 00:04:22,360 Speaker 2: ring age have been far ranging from four point five 75 00:04:22,400 --> 00:04:25,320 Speaker 2: billion years the leftovers of when Saturn itself was forming, 76 00:04:25,600 --> 00:04:28,440 Speaker 2: to a few tens of million years, But with this 77 00:04:28,520 --> 00:04:30,840 Speaker 2: new finding in hand, it looks like the rings are 78 00:04:31,040 --> 00:04:33,920 Speaker 2: very young, formed less than one hundred million years ago 79 00:04:34,040 --> 00:04:37,119 Speaker 2: and perhaps as recently as ten million years ago. Where 80 00:04:37,160 --> 00:04:39,800 Speaker 2: the rings came from remains more of a mystery. It's 81 00:04:39,839 --> 00:04:42,479 Speaker 2: possible that an icy object from the Kuiper Belt or 82 00:04:42,520 --> 00:04:45,960 Speaker 2: an arrant comet became entwined in Saturn's gravitational field and 83 00:04:46,000 --> 00:04:49,039 Speaker 2: succumbed to the planet's powerful tides, was ripped apart and 84 00:04:49,080 --> 00:04:51,920 Speaker 2: eventually ground down to create the banded rings we know 85 00:04:52,040 --> 00:04:55,240 Speaker 2: and love today. Although Saturn's rings will be gone in 86 00:04:55,240 --> 00:04:57,520 Speaker 2: a hundred million years, it doesn't mean that our Solar 87 00:04:57,600 --> 00:05:01,160 Speaker 2: systems ringed planet days are gone forever. If Saturn can 88 00:05:01,200 --> 00:05:04,360 Speaker 2: create them, there's little reason why Jupiter, Neptune, or Uranus 89 00:05:04,560 --> 00:05:07,640 Speaker 2: can't shred and nice the object create another bright ringed planet. 90 00:05:07,680 --> 00:05:09,280 Speaker 2: Display in the distant future. 91 00:05:18,480 --> 00:05:21,400 Speaker 1: Today's episode is based on the article Saturn's Rings will 92 00:05:21,400 --> 00:05:24,360 Speaker 1: exist for just a blippin time on how stuffworks dot Com, 93 00:05:24,400 --> 00:05:27,680 Speaker 1: written by Ian O'Neill. Brain Stuff is production of iHeartRadio 94 00:05:27,720 --> 00:05:30,000 Speaker 1: in partnership with how Stuffworks dot Com and is produced 95 00:05:30,000 --> 00:05:33,400 Speaker 1: by Tyler Klang. Four more podcasts my heart Radio, visit 96 00:05:33,400 --> 00:05:36,240 Speaker 1: the iHeartRadio app, Apple Podcasts, or wherever you listen to 97 00:05:36,279 --> 00:05:37,159 Speaker 1: your favorite shows.