WEBVTT - The Moons of Uranus, Part 2 0:00:01.680 --> 0:00:05.040 This is the USS Hamlet's Father's Ghost, requesting entry into 0:00:05.160 --> 0:00:09.560 Uranian orbit and the Uranian satellite system. We have decelerated 0:00:09.600 --> 0:00:11.320 and see clearance to titanium. 0:00:11.520 --> 0:00:15.200 Greetings, USS Hamlet's Father's Ghost. This is Mustard Seed. Can 0:00:15.240 --> 0:00:16.520 you state the purpose of your visit? 0:00:16.920 --> 0:00:18.079 Roger that Mustard Seed. 0:00:18.120 --> 0:00:20.760 I have two hundred and fifty Shakespeare enthusiast on board, 0:00:20.880 --> 0:00:23.360 just waking up for a tour of the Uranian moons. 0:00:23.880 --> 0:00:26.920 Our visit to the Royal Automated Uranian Theater on Titanius 0:00:26.960 --> 0:00:28.360 should be registered in the lock. 0:00:29.040 --> 0:00:33.800 All right, Roger that USSHFG. I can confirm your reservation 0:00:34.000 --> 0:00:38.160 now and docking credentials are good to go with your passengers. 0:00:38.200 --> 0:00:41.320 A pleasant and safe visit to the Uranian satellite system. 0:00:41.440 --> 0:00:46.360 The next automated Thespianoid performance will be let's see Ooh 0:00:46.800 --> 0:00:49.280 Edward the third Well, better luck next time. 0:00:53.640 --> 0:00:57.800 Welcome to Stuff to Blow Your Mind, the production of iHeartRadio. 0:01:03.560 --> 0:01:05.479 Hey you, welcome to Stuff to Blow your Mind. 0:01:05.600 --> 0:01:08.560 My name is Robert Lamb and I'm Joe McCormick, and 0:01:08.600 --> 0:01:11.280 we're back with Part two of our series on the 0:01:11.319 --> 0:01:15.520 planet Uranus and its moons. Now in Part one, we 0:01:15.640 --> 0:01:19.880 focused mainly on the planet itself. This time we're going 0:01:19.920 --> 0:01:22.880 to start getting more into the moons. Maybe we'll do 0:01:23.000 --> 0:01:25.399 all of the moons this time. I think last time 0:01:25.400 --> 0:01:27.600 we promised it would happen. We'll see whether we can 0:01:27.600 --> 0:01:30.240 fit it all into one episode. But I had a 0:01:30.280 --> 0:01:33.200 few more core planet digressions burning a hole in my 0:01:33.240 --> 0:01:36.039 pocket that I wanted to mention before we fly off 0:01:36.080 --> 0:01:38.679 to the satellites. Are you okay with that? Rob, Let's 0:01:38.680 --> 0:01:38.960 do it. 0:01:39.400 --> 0:01:39.480 So. 0:01:39.680 --> 0:01:42.800 First of all, I was wondering what's the density of Uranus, 0:01:43.280 --> 0:01:46.880 And it turns out that Uranus is the second least 0:01:47.200 --> 0:01:50.360 dense planet in the Solar System at one point twenty 0:01:50.360 --> 0:01:54.160 seven grams per cubic centimeter. The only planet less dense 0:01:54.240 --> 0:01:57.600 is actually Saturn, the second largest planet in the Solar System. 0:01:58.160 --> 0:02:01.320 You might wonder which planet is the dense baby, that's Earth. 0:02:01.640 --> 0:02:02.160 That's Earth. 0:02:02.440 --> 0:02:04.520 We are at five point five to one grams per 0:02:04.520 --> 0:02:08.120 cubic centimeter, so we are the density king. But one 0:02:08.200 --> 0:02:10.760 of the real things I wanted to return to was 0:02:10.760 --> 0:02:14.360 a question of materials, because in the last episode we 0:02:15.080 --> 0:02:18.440 mentioned just giving sort of an overview of the basics 0:02:18.440 --> 0:02:22.160 of the planet, that most of the mass of Uranus 0:02:22.400 --> 0:02:27.320 is thought to be a hot, dense fluid of ices, 0:02:27.800 --> 0:02:31.600 probably surrounding a rocky core of some sort. And though 0:02:32.080 --> 0:02:34.600 it might be kind of strange to hear like hot 0:02:35.080 --> 0:02:38.639 dense fluid of ices, that almost kind of doesn't make 0:02:38.680 --> 0:02:41.520 sense based on our definition of ice. And it's true 0:02:41.560 --> 0:02:43.120 that a lot of this ice is going to be 0:02:43.240 --> 0:02:46.280 different than the kind of ice we know. So I 0:02:46.320 --> 0:02:48.560 was reading more about this in an article by a 0:02:48.639 --> 0:02:53.120 planetary atmospheric scientist named Amy Simon, who is a senior 0:02:53.160 --> 0:02:56.520 researcher at NASA Goddard, and this was written for the 0:02:56.560 --> 0:02:59.680 magazine of the Planetary Society. The article is called the 0:03:00.400 --> 0:03:03.560 of the Ice Giants, and one of the questions Simon 0:03:03.560 --> 0:03:07.960 addresses in this article is why are the planets Uranus 0:03:08.040 --> 0:03:12.920 and Neptune called ice giants as opposed to regular gas giants. 0:03:13.280 --> 0:03:17.200 It's because, compared to regular gas giants like Jupiter and Saturn, 0:03:17.320 --> 0:03:20.880 Uranus and Neptune are composed of a higher proportion of 0:03:21.040 --> 0:03:25.840 ice forming molecules like water and methane, though much of 0:03:25.880 --> 0:03:29.799 that so called ice is in a phase unfamiliar to 0:03:29.880 --> 0:03:33.000 us on the surface of Earth. Cymon writes quote, ice 0:03:33.080 --> 0:03:36.520 giants are mostly water, probably in the form of a 0:03:36.640 --> 0:03:41.880 supercritical fluid. The visible clouds likely consist of ice crystals 0:03:41.920 --> 0:03:47.720 with different compositions, So regarding supercritical fluid, a supercritical fluid 0:03:47.800 --> 0:03:51.840 doesn't behave exactly like a liquid, gas or a solid. 0:03:51.960 --> 0:03:56.360 It's an emergent state of matter occurring at temperatures and 0:03:56.440 --> 0:04:00.240 pressures beyond what is known as the critical point for 0:04:00.280 --> 0:04:04.840 each substance. And Simon has a very good paragraph clarifying 0:04:04.920 --> 0:04:08.280 the planetary science use of the term ice, which could 0:04:08.320 --> 0:04:11.280 help clear up any confusion there. She says that on 0:04:11.360 --> 0:04:13.880 Earth we usually use the term ice to refer to 0:04:14.000 --> 0:04:16.760 just water H two O when it is frozen solid, 0:04:17.160 --> 0:04:20.360 but planetary astronomers use the word ice to refer to 0:04:20.600 --> 0:04:25.520 any condensable molecule in its solid form. She writes, quote, 0:04:25.760 --> 0:04:30.760 these tend to be highly reflective form clouds, and unlike minerals, 0:04:31.160 --> 0:04:35.360 can readily change between liquid, solid and gas states at 0:04:35.400 --> 0:04:40.160 relatively low temperatures. So we're mainly familiar with water ice 0:04:40.240 --> 0:04:43.160 on the surface of Earth, but throughout space there are 0:04:43.279 --> 0:04:48.240 lots of ices. There's methane, ammonia, hydrogen sulfide, and phosphene 0:04:48.240 --> 0:04:52.839 pH three, and these are all condensable molecules and could 0:04:52.920 --> 0:04:56.839 all freeze in the atmosphere of Uranus and Neptune also 0:04:56.920 --> 0:04:59.680 for that matter, and Simon writes that most of the 0:04:59.680 --> 0:05:02.360 cloud clouds we see in the atmospheres of these ice 0:05:02.440 --> 0:05:07.400 giants are clouds of methane ice crystals or hydrogen sulfide ice, 0:05:07.640 --> 0:05:12.280 So there's probably weird supercritical fluids down below, and then 0:05:12.279 --> 0:05:16.080 an atmosphere above. The atmosphere in its gas contents, is 0:05:16.160 --> 0:05:20.280 mostly hydrogen and helium, but that atmosphere is probably full 0:05:20.360 --> 0:05:23.360 of traces of different kinds of ice, including not just 0:05:23.960 --> 0:05:27.320 H two O, but things like ammonia and methane. And 0:05:27.560 --> 0:05:31.600 speaking of methane, as we mentioned last time, the blue 0:05:31.720 --> 0:05:35.720 color of both Neptune and Uranus appears to come from 0:05:35.839 --> 0:05:39.720 the presence of methane in their atmospheres, which absorbs the 0:05:39.760 --> 0:05:43.600 red wavelengths of light from the sun and reflects only 0:05:43.640 --> 0:05:47.800 the blue spectrum. But the question is why is Urinus 0:05:47.880 --> 0:05:50.680 a paler shade of blue than Neptune. If you look 0:05:50.720 --> 0:05:53.359 at Neptune, it's often kind of a royal blue, whereas 0:05:53.400 --> 0:05:58.200 in true color, Uranus appears kind of a gray green blue. 0:05:58.680 --> 0:06:01.920 Simon writes that this is quote either because Urinus has 0:06:02.040 --> 0:06:05.560 more haze, so more kind of a cloudy outer shell, 0:06:06.720 --> 0:06:09.679 but she goes on or because Neptune's atmosphere has another 0:06:10.080 --> 0:06:15.600 unidentified constituent that absorbs longer wavelength light even more strongly, 0:06:15.720 --> 0:06:18.600 and of course longer wavelength light would be more red 0:06:18.600 --> 0:06:21.800 shifted toward the red end of the visible spectrum. Okay, 0:06:21.800 --> 0:06:24.919 so that's ice, the atmosphere, the makeup of the planet. 0:06:24.920 --> 0:06:27.240 But there's one more thing you may have seen headlines 0:06:27.279 --> 0:06:30.920 about regarding Urinus in Neptune that if you have seen 0:06:30.920 --> 0:06:33.520 these headlines, I'm sure you're wondering about it, and that 0:06:33.680 --> 0:06:37.040 is the claim that some experts have argued that it 0:06:37.240 --> 0:06:42.680 likely rains diamonds on Urinus in Neptune. And from what 0:06:42.760 --> 0:06:45.880 I can tell, this is true. Now, this is obviously 0:06:45.880 --> 0:06:49.840 something we haven't been able to detect directly with probes 0:06:49.920 --> 0:06:54.120 or anything, so nobody can sense this happening. Instead, it's 0:06:54.160 --> 0:06:56.960 based on what we do know about the planets and 0:06:57.240 --> 0:07:01.039 argue and sort of extrapolating logically from the starting facts. 0:07:01.320 --> 0:07:03.880 So how does the logic go? Well, I was reading 0:07:03.920 --> 0:07:07.039 about this in an article for space dot Com by 0:07:07.080 --> 0:07:12.000 the Sunny Stonybrook astrophysicist Paul M. Sutter, and in this article, 0:07:12.080 --> 0:07:16.440 Sutter explains that we know from mathematical models that the 0:07:16.480 --> 0:07:21.160 inner mantles of ice giants probably have temperatures of about 0:07:21.240 --> 0:07:25.480 seven thousand kelvins or over sixty seven hundred celsius and 0:07:25.680 --> 0:07:29.720 pressure about six million times the atmospheric pressure on the 0:07:29.760 --> 0:07:33.600 surface of Earth. Meanwhile, higher up in the mantle, things 0:07:33.600 --> 0:07:37.600 are cooler about two thousand kelvins and only two hundred 0:07:37.640 --> 0:07:42.560 thousand times Earth's atmospheric pressure. And we know that water, ammonia, 0:07:42.640 --> 0:07:46.120 and methane are present within that mantle. So what happens 0:07:46.120 --> 0:07:50.920 to those substances in those conditions, Well, these conditions of 0:07:50.960 --> 0:07:55.800 temperature and pressure would tend to tear apart molecules of methane, 0:07:55.920 --> 0:08:00.520 methane is H four carbon, and hydrogen. And when those 0:08:00.640 --> 0:08:04.200 molecules get torn apart, we are left with free carbon. 0:08:04.360 --> 0:08:08.320 Free carbon tends to link together with other free carbon 0:08:08.600 --> 0:08:12.400 to form long chains of carbon. What happens to long 0:08:12.480 --> 0:08:16.320 chains of pure carbon under high pressure that gets pressed 0:08:16.400 --> 0:08:20.320 into a diamond? These diamonds would tend to then drop 0:08:20.400 --> 0:08:24.760 down to lower in the mantle where high temperatures vaporize them, 0:08:24.880 --> 0:08:27.679 and then they float back up into the upper mantle, 0:08:27.760 --> 0:08:31.440 and then the cycle repeats, so you're left with diamond rain. 0:08:32.120 --> 0:08:35.360 Sounds like the name of a great alternate universe collaborative 0:08:35.400 --> 0:08:38.640 sci fi movie musical between Prince and David Bowie. Wish 0:08:38.640 --> 0:08:40.920 I could have seen it, but it does appear to 0:08:40.920 --> 0:08:44.600 be very likely a physical reality on Uranus and Neptune 0:08:44.640 --> 0:08:45.040 as well. 0:08:45.800 --> 0:08:48.800 So you're saying that all we have to do is 0:08:49.360 --> 0:08:53.640 jet out to Urinus, dip down into the atmosphere of Uranus, 0:08:53.880 --> 0:08:57.200 scoop up some diamonds, then get back to Earth and 0:08:57.240 --> 0:08:58.199 we're set for life. 0:08:58.520 --> 0:09:00.640 I've always said when I look at but the stars 0:09:00.679 --> 0:09:05.800 at night, what I see is profit. Okay, but one 0:09:05.800 --> 0:09:09.400 more digression before we get to the moons. Since part one, 0:09:09.480 --> 0:09:12.120 we actually got a really great bit of listener mail 0:09:12.360 --> 0:09:15.240 from Joe, not me, but a different Joe who listens 0:09:15.280 --> 0:09:18.800 to the show, who brought to our attention some really 0:09:18.840 --> 0:09:22.400 awesome photos of Uranus recently captured by the James Web 0:09:22.440 --> 0:09:26.679 Space Telescope. Joe writes, quote, I've long awaited with tremulous 0:09:26.679 --> 0:09:30.839 anticipation the resumption of your ural journey to the Heliopause 0:09:31.200 --> 0:09:34.240 and was thrilled to see the recumbent sky King Uranus 0:09:34.240 --> 0:09:37.920 on my podcast Feed Your Choice was timely indeed, as 0:09:37.960 --> 0:09:41.200 the James Web Space Telescope just last month released some 0:09:41.360 --> 0:09:46.120 spectacular visuals of Uranus. These images bost greater clarity than 0:09:46.120 --> 0:09:49.640 the Hubbles effort, especially of the planet's rings. I love 0:09:49.720 --> 0:09:51.840 living under a sky that will never run out of 0:09:51.840 --> 0:09:54.640 extraordinary things to look at and talk about, and I 0:09:54.679 --> 0:09:59.160 appreciate when you cast your gaze upward from time to time. Joe, Well, 0:09:59.160 --> 0:10:01.360 thank you, Joe. Because I had not seen these, I 0:10:01.400 --> 0:10:04.960 looked them up and this is fantastic. So I saw 0:10:05.000 --> 0:10:08.720 these within the context of a NASA press release from 0:10:08.800 --> 0:10:12.520 April sixth, twenty twenty three that Joe shared with us Rob, 0:10:12.520 --> 0:10:15.480 I pasted these two photos here in the outline. One 0:10:15.559 --> 0:10:18.120 is just zoomed in on the planet from the more 0:10:18.200 --> 0:10:21.560 zoomed out second one. I would say, from my perspective, 0:10:21.960 --> 0:10:26.160 these images are gorgeous. They fill one with awe at 0:10:26.200 --> 0:10:29.319 the picture of this frosty, dark recess where the Blue 0:10:29.360 --> 0:10:32.800 God lives. And this might sound a little bit weird, 0:10:33.040 --> 0:10:35.760 but I actually mean this in the best possible way. Somehow, 0:10:35.800 --> 0:10:40.719 in these images, Urinus looks more like an optical artifact 0:10:41.000 --> 0:10:44.640 than a physical object, as if the planet were like 0:10:44.760 --> 0:10:48.920 a glint or a lens flare. And to explain what 0:10:48.960 --> 0:10:51.600 I mean, so the planet is pictured on its side, 0:10:51.640 --> 0:10:54.559 because of course that's how it is. We're not seeing 0:10:54.559 --> 0:10:58.160 the rings laterally from the side, crossing over and behind 0:10:58.240 --> 0:11:01.439 the planet, like we do in most photos of Saturn. Instead, 0:11:01.440 --> 0:11:04.720 we're seeing the rings encircling the planet in an egg 0:11:04.760 --> 0:11:08.600 shape because we're looking roughly down toward the north pole, 0:11:09.440 --> 0:11:13.920 which faces sideways. And in this particular photo, though this 0:11:14.040 --> 0:11:17.640 is not exactly true color, the planet is pale blue 0:11:17.640 --> 0:11:21.000 with a white cap, and the rings sort of fade 0:11:21.200 --> 0:11:26.000 outward to inward from a screaming fluorescent white to a 0:11:26.200 --> 0:11:29.960 dim blue gray as they sink toward the planet's atmosphere. 0:11:30.600 --> 0:11:33.760 And the sunlight seems blinding in these images because we 0:11:33.840 --> 0:11:36.520 actually see it gleaming off the edge of the planet, 0:11:36.559 --> 0:11:39.600 which is even weirder because, as I said, the disk 0:11:39.679 --> 0:11:42.480 of Urinus facing us looks like a glint or a 0:11:42.520 --> 0:11:45.559 gleam itself. And in the more zoomed out of these 0:11:45.600 --> 0:11:48.120 two photos, we can see the blue dots of the 0:11:48.200 --> 0:11:52.000 larger moons surrounding it, also sending out these sort of 0:11:52.080 --> 0:11:56.000 shafts of reflected light in these hexagonal criss crosses out 0:11:56.040 --> 0:11:56.600 into space. 0:11:57.120 --> 0:11:59.880 Yeah, these images are gorgeous. It makes it look like 0:12:00.160 --> 0:12:06.560 Urinus is a planet designed by Japanese illustrator Hajimi Soriyama, whose, 0:12:06.600 --> 0:12:09.200 of course I think he worked on the design for 0:12:09.240 --> 0:12:15.760 the original Sony Aibo robot, but also mostly known for 0:12:17.200 --> 0:12:21.640 robot pin up like really shiny, silvery robot pin up models. 0:12:22.800 --> 0:12:25.280 This artist is on my mind because the movie we're 0:12:25.320 --> 0:12:29.160 watching Friday in for Weird House Cinema, this artist is 0:12:29.240 --> 0:12:32.200 credited like deep down in the credits because there's a 0:12:32.280 --> 0:12:34.160 character in the movie that has some of this art 0:12:34.280 --> 0:12:38.760 up on his workstation. But this kind of but there's 0:12:38.800 --> 0:12:43.560 a certain aside from like the female robot bodies in 0:12:43.559 --> 0:12:46.440 his art, there is this kind of like glimmering, like 0:12:46.559 --> 0:12:50.400 silvery perfection to things. And that's what that's what I 0:12:50.480 --> 0:12:53.240 kind of get from this image of Urinus. And if 0:12:53.280 --> 0:12:55.400 you're into planets, like I mean, put it on a calendar. 0:12:55.480 --> 0:12:56.600 It looks it looks nice. 0:12:56.840 --> 0:12:58.920 It is beautiful. And I will say the blue in 0:12:58.960 --> 0:13:01.960 this photo, as I alluded to, is not exactly true 0:13:01.960 --> 0:13:05.400 color from the visible spectrum. I think it's approximate. So 0:13:05.760 --> 0:13:09.360 the image is from the webs near infrared camera combining 0:13:09.440 --> 0:13:13.000 data from two filters. According to the press release, it 0:13:13.080 --> 0:13:16.400 was one point four and three point zero microns, and 0:13:16.440 --> 0:13:19.079 then the article explains these are coded out to blue 0:13:19.120 --> 0:13:23.960 and orange respectively. Now I mentioned the white cap that 0:13:24.000 --> 0:13:28.040 we see on Uranus in this photo. The article explains 0:13:28.080 --> 0:13:30.520 that this is known as the polar cap, and it 0:13:30.559 --> 0:13:34.160 seems to manifest when the pole of the planet goes 0:13:34.240 --> 0:13:38.000 into direct sunlight during its long polar summer, which, again, 0:13:38.640 --> 0:13:41.200 as we talked about last time, lasts many earth years 0:13:41.240 --> 0:13:43.920 at a time, and then the cap seems to disappear 0:13:44.040 --> 0:13:46.480 in the fall when it starts to turn away from 0:13:46.480 --> 0:13:49.040 the sun. As far as I could find, we aren't 0:13:49.080 --> 0:13:51.960 sure exactly what causes this, or maybe if somebody knows, 0:13:51.960 --> 0:13:54.640 I just didn't dig that up. But so regarding the 0:13:54.720 --> 0:13:59.840 beautiful rings in the picture, Urinus has thirteen known rings, 0:14:00.040 --> 0:14:02.440 and you can see eleven of them in this photo, 0:14:02.520 --> 0:14:05.560 though some of them are so bright that they bleed 0:14:05.559 --> 0:14:08.800 together in the image. There are nine major rings and 0:14:08.840 --> 0:14:11.280 then there are two kind of faint dusty rings that 0:14:11.320 --> 0:14:14.240 were discovered during the approach of Voyager two in nineteen 0:14:14.280 --> 0:14:18.400 eighty six. But speaking of those, rings and moons. Rings 0:14:18.400 --> 0:14:22.160 and moons sometimes have an interesting origin story, so I 0:14:22.200 --> 0:14:26.040 was wondering where do experts generally think they came from 0:14:26.280 --> 0:14:29.120 in the case of Uranus. Going back to that Planetary 0:14:29.160 --> 0:14:32.920 Society article by Amy Simon, Simon writes that the medium 0:14:32.960 --> 0:14:37.320 sized moons of Uranus probably formed in place at the 0:14:37.360 --> 0:14:41.920 same time or after whatever event it was that left 0:14:42.040 --> 0:14:44.560 Uranus tilted on its side. And as we talked about 0:14:44.600 --> 0:14:48.200 last time, it seems likely that Uranus was probably knocked 0:14:48.240 --> 0:14:50.680 on its side and left colder than all the other 0:14:50.720 --> 0:14:54.920 planets because of an impact with a large object, maybe 0:14:54.920 --> 0:14:58.720 like an Earth sized planet billions of years ago. And 0:14:58.800 --> 0:15:02.120 so what we're left with is that the moons orbit 0:15:02.320 --> 0:15:06.160 Urinus on its equatorial plane, so like the planet itself 0:15:06.280 --> 0:15:09.960 and like its rings, the moons are tilted at a 0:15:10.080 --> 0:15:13.200 roughly ninety degree angle to the rest of the Solar System. 0:15:13.720 --> 0:15:16.200 In general, the moons of Urinus are made of ice 0:15:16.320 --> 0:15:20.000 and rock, usually slightly more ice than rock, and they 0:15:20.040 --> 0:15:24.240 show some interesting surface features, like patterns of darkening on 0:15:24.320 --> 0:15:29.040 their surfaces that are caused by some unknown material. Spectral 0:15:29.040 --> 0:15:33.000 analysis reveals the presence of frozen carbon dioxide on a 0:15:33.000 --> 0:15:36.960 lot of the moons. Meanwhile, the origin of the rings, 0:15:37.040 --> 0:15:41.640 the consensus seems to be that they are created by 0:15:41.680 --> 0:15:46.840 the shattering into dust and fragments of formerly solid moons. 0:15:47.120 --> 0:15:49.880 And as we've seen with other planets, the sudden or 0:15:50.000 --> 0:15:53.240 gradual smash up of moons can happen a number of ways, 0:15:53.960 --> 0:15:58.480 by lots of little collisions with meteoroids or other objects, 0:15:58.600 --> 0:16:01.760 or by tidal breakup due to gravity, in any case, 0:16:01.840 --> 0:16:07.600 turning former larger satellites into smaller satellites and rings of 0:16:07.720 --> 0:16:08.640 little fragments. 0:16:08.960 --> 0:16:12.720 Yeah, it's fascinating. How from our human perspective we look 0:16:12.800 --> 0:16:15.200 up at our moon, we consider the moons of other worlds, 0:16:15.240 --> 0:16:17.680 and there's a certain certain stability to them, you know. 0:16:18.680 --> 0:16:20.840 But if you look at. 0:16:20.600 --> 0:16:27.120 Any planets, moons or moon, generally, you're looking at a 0:16:27.120 --> 0:16:32.600 more violent relationship over the vast history of a given planet. 0:16:33.080 --> 0:16:45.320 There's nothing peaceful about it. All right, Well, let's begin, 0:16:45.600 --> 0:16:49.280 at least begin to dip into the moons of Uranus. 0:16:50.080 --> 0:16:51.920 Like I said, we originally set out to do them all. 0:16:51.960 --> 0:16:54.280 Maybe we won't do them all. Maybe we'll get part 0:16:54.360 --> 0:16:57.400 way through the journey and we'll come back on Tuesday. 0:16:58.120 --> 0:17:00.880 Who knows, Maybe we'll just we'll just get we'll finish 0:17:00.960 --> 0:17:02.800 them up, and then we'll go right into Neptune. 0:17:03.800 --> 0:17:05.920 There are no rules. We can do what we want. 0:17:06.720 --> 0:17:09.440 So let's start with the inner moons of Uranus thirteen 0:17:09.520 --> 0:17:12.280 total known. All right, We're going to start with a 0:17:12.320 --> 0:17:17.600 pair of moons, Cordelia and Ophelia. These are named for 0:17:17.800 --> 0:17:20.760 the youngest daughter of King Lear and of course Hamlet's 0:17:20.880 --> 0:17:26.919 tragic beloved, respectively. The main significance of these moons is 0:17:26.960 --> 0:17:30.600 that both Cordelia and Ophelia are shepherd moons, as their 0:17:30.600 --> 0:17:34.360 gravity keeps Uranus's epsilon ring from dispersing. 0:17:34.600 --> 0:17:37.080 Now, I thought this was interesting, so I was looking 0:17:37.160 --> 0:17:41.159 up how exactly it is that shepherd moons work. What 0:17:41.160 --> 0:17:45.200 does the shepherd moon do? These little small moons, how 0:17:45.240 --> 0:17:49.080 do they keep a ring? Essentially, they keep a ring 0:17:49.240 --> 0:17:52.880 in tight formation around the planet and clear these gaps 0:17:52.920 --> 0:17:56.440 between the rings. And it seems that essentially it works 0:17:56.520 --> 0:17:59.480 like this. So you've got a small moon and it's 0:17:59.600 --> 0:18:03.000 orbiting planet. And imagine at first it's orbiting the planet 0:18:03.160 --> 0:18:07.639 along with a bunch of other small particles sort of 0:18:07.680 --> 0:18:12.120 within the lane of that small moon's orbit. Particles that 0:18:12.280 --> 0:18:16.720 are ahead of the small moon will be attracted by 0:18:16.840 --> 0:18:20.560 gravity to it, meaning if they're orbiting ahead of it, 0:18:20.600 --> 0:18:23.600 they will naturally want to slow down in their orbit, 0:18:23.680 --> 0:18:27.920 right because they're getting pulled toward this moon. But slowing 0:18:27.960 --> 0:18:31.199 down in their orbit actually causes them to lose energy 0:18:31.640 --> 0:18:35.000 and fall down closer to the planet that they're orbiting. 0:18:35.080 --> 0:18:37.359 So these like dust and particles and things in the 0:18:37.440 --> 0:18:43.680 ring actually end up sorting down into lower orbit rings. 0:18:44.200 --> 0:18:47.880 And then meanwhile, things that are orbiting along the same 0:18:48.000 --> 0:18:51.080 lane as this moon, that are behind it in its 0:18:51.200 --> 0:18:55.000 orbit are attracted to it and thus sped up. And 0:18:55.040 --> 0:18:58.280 as they get sped up trying to chase after this 0:18:58.680 --> 0:19:02.040 moon by the force of gravity, that acceleration actually causes 0:19:02.119 --> 0:19:05.160 them to have greater energy and to ascend in their 0:19:05.280 --> 0:19:08.760 orbit and end up going into outer rings beyond that 0:19:08.960 --> 0:19:09.480 little moon. 0:19:10.359 --> 0:19:12.959 So again we have the Shepherd moons here. They were 0:19:13.000 --> 0:19:16.840 discovered by Voyager two in nineteen eighty six. Like the 0:19:16.880 --> 0:19:19.080 rest of Uranus's inner moons, they appear to be roughly 0:19:19.119 --> 0:19:23.239 equal split of water, ice and rock. They're small. Of 0:19:23.320 --> 0:19:27.200 note to Cordelia is the closest to the planet, and 0:19:27.520 --> 0:19:30.560 I guess we should also point out or come back 0:19:30.560 --> 0:19:34.320 to the fact that yes, these are both Shakespearean references. 0:19:34.520 --> 0:19:37.240 There are going to be a lot of shakespeare references 0:19:37.320 --> 0:19:40.560 as we go through the moons of Uranus, and these 0:19:40.560 --> 0:19:41.440 are just the first two. 0:19:41.680 --> 0:19:43.600 It seems that a lot of the names of these 0:19:43.640 --> 0:19:46.600 satellites for some reason were chosen either from the works 0:19:46.600 --> 0:19:50.440 of Shakespeare or from the works of Alexander Pope. 0:19:50.920 --> 0:19:55.680 Yeah, predominantly Shakespearean, but definitely there's some key Alexander Pope 0:19:55.720 --> 0:19:58.159 references as well. So as we go through it, we 0:19:58.240 --> 0:20:01.800 can probably talk a little bit about some the namesakes here. 0:20:02.040 --> 0:20:04.359 Well, this was something I was wondering. I don't know 0:20:04.359 --> 0:20:07.560 about the origin exactly, like what people had in mind 0:20:07.640 --> 0:20:10.919 when they were naming these, But so I think, like, 0:20:11.080 --> 0:20:15.480 is there some significance to the innermost minor moon here 0:20:15.920 --> 0:20:20.800 being called Cordelia, because Cordelia is a very poignant character. 0:20:21.080 --> 0:20:24.439 Cordelia is the youngest daughter of King Lear in the 0:20:24.480 --> 0:20:26.359 play King Lear. If you don't know the play or 0:20:26.440 --> 0:20:29.359 need refreshing, the very beginning of it, the first scene 0:20:29.560 --> 0:20:32.960 is King Lear is this old king. He comes out. 0:20:32.960 --> 0:20:35.800 He decides that he will divide up his kingdom between 0:20:35.800 --> 0:20:40.560 his three daughters, Goneril, Reagan, and Cordelia, and he's going 0:20:40.600 --> 0:20:43.680 to give the largest portion to the daughter that loves 0:20:43.760 --> 0:20:48.080 him most. So Goneril and Reagan give these speeches where 0:20:48.080 --> 0:20:52.159 they overwhelm their father with absurd insincere flattery about how 0:20:52.200 --> 0:20:55.480 much they love him. And then when it's Cordelia's time 0:20:55.520 --> 0:20:59.960 to speak, she finds that she cannot put into words, 0:21:00.080 --> 0:21:03.879 She cannot express her love for her father to herself. 0:21:03.920 --> 0:21:06.360 She says that she knows her love is richer than 0:21:06.400 --> 0:21:09.040 her tongue. And then when it's her time to speak, 0:21:09.080 --> 0:21:11.760 she says, unhappy that I am. I cannot heave my 0:21:11.920 --> 0:21:15.520 heart into my mouth. I love your majesty according to 0:21:15.560 --> 0:21:19.560 my bond, no more nor less. And I think he 0:21:19.560 --> 0:21:22.639 gives her a chance to amend her statement. She doesn't really, 0:21:22.720 --> 0:21:26.040 and then so Lee gets furious at this decides to 0:21:26.080 --> 0:21:29.719 disinherit her. He gives nothing to Cordelia, splits his kingdom 0:21:30.040 --> 0:21:33.840 between the other two daughters, Goneril and Reagan, who secretly 0:21:33.920 --> 0:21:35.720 think he is a fool and they will go on 0:21:35.800 --> 0:21:38.840 to betray him once they come to power. And of 0:21:38.840 --> 0:21:41.439 course it's a tragedy, so things just get worse and worries. 0:21:41.480 --> 0:21:44.600 Basically everybody ends up dead but you know, it's a 0:21:44.720 --> 0:21:47.800 very meaningful character and something I think, I don't know. 0:21:47.840 --> 0:21:50.439 That moment in the first scene is something that always 0:21:50.440 --> 0:21:53.080 got me, something I can really relate to, Like the 0:21:53.119 --> 0:21:59.359 feeling of worrying that you don't express positive feelings because 0:21:59.400 --> 0:22:02.960 you're afraid that you can't phrase them in the sincerest way, 0:22:03.040 --> 0:22:04.720 like you don't know how to put them to words. 0:22:04.760 --> 0:22:07.320 So then you worry that like you're perceived as not 0:22:07.400 --> 0:22:09.440 wanting to say a positive thing at all. I don't 0:22:09.440 --> 0:22:10.680 know if that makes sense. 0:22:11.400 --> 0:22:13.440 No, no, no, no, I mean, certainly with the example 0:22:14.760 --> 0:22:17.320 here from the play, absolutely. 0:22:17.160 --> 0:22:20.320 But she's the daughter that truly loved him. She just 0:22:20.440 --> 0:22:23.679 didn't want to give a big, insincere speech. 0:22:24.240 --> 0:22:24.640 Anyway. 0:22:24.640 --> 0:22:26.680 It's a very meaningful character. So I'm wondering, is there 0:22:26.760 --> 0:22:29.119 some similarly at play here in the selection of the 0:22:29.200 --> 0:22:31.159 name for this moon? Maybe not so, Like it's a 0:22:31.280 --> 0:22:35.159 very small satellite, it's the closest to the planet of these. 0:22:35.320 --> 0:22:38.439 It is one of the shepherd moons that sort of 0:22:38.840 --> 0:22:42.360 guides the Epsilon ring and keeps it tight in formation. 0:22:43.359 --> 0:22:46.080 By the end, I mean, she does show great discipline 0:22:46.119 --> 0:22:49.200 because she comes back with an army to try to 0:22:49.200 --> 0:22:53.560 to fight on her father's side against her cruel, duplicitous sisters. 0:22:54.200 --> 0:22:56.359 I don't know, maybe not. I don't know if it fits, 0:22:56.400 --> 0:22:57.480 but I was wondering. 0:22:58.320 --> 0:23:02.200 No, I think it's natural to try and read some 0:23:02.240 --> 0:23:04.440 sort of sense into the naming. 0:23:04.680 --> 0:23:04.880 Though. 0:23:04.920 --> 0:23:07.439 Of course, as we'll discuss it, it's different people at 0:23:07.440 --> 0:23:10.199 different times coming up with these names. You know, some 0:23:10.320 --> 0:23:13.520 are maybe probably a little more up on the works 0:23:13.520 --> 0:23:16.959 of William Shakespeare than others. Sometimes there's there seems like 0:23:17.000 --> 0:23:19.199 something they could be getting, at other times not. And 0:23:19.480 --> 0:23:23.159 also some of these kind of slip by on a technicality, 0:23:24.040 --> 0:23:26.919 so they're kind of all over the place. All right, 0:23:26.960 --> 0:23:29.720 let's let's go into the next one. There's a Bianca 0:23:29.800 --> 0:23:33.200 named after Kate's sister in the Taming of the Shrew. 0:23:34.160 --> 0:23:36.879 This one does nothing really else that I think is 0:23:36.920 --> 0:23:39.840 significant about it, and it was also discovered by Voyager two. 0:23:40.119 --> 0:23:42.679 All right, after that, we have Cressida. This is the 0:23:42.680 --> 0:23:46.920