WEBVTT - From the Vault: The Moons of Uranus, Part 2 0:00:06.040 --> 0:00:08.000 Hey you, welcome to Stuff to Blow your Mind. We 0:00:08.039 --> 0:00:10.160 have another vault episode for you. This is going to 0:00:10.160 --> 0:00:14.160 be The Moons of Uruana's Part two, which originally published 0:00:14.320 --> 0:00:17.119 on five eleven, twenty twenty three. This is part two 0:00:17.400 --> 0:00:22.840 of three. Please enjoy. This is the uss Hamlet's Father's 0:00:22.880 --> 0:00:27.320 Ghost requesting entry into Uranian orbit and the Uranian satellite system. 0:00:27.720 --> 0:00:30.880 We have decelerated and seek clearance to Titanium. 0:00:30.880 --> 0:00:34.560 Greetings, USS Hamlet's Father's Ghost. This is Mustard Seed. Can 0:00:34.600 --> 0:00:35.880 you state the purpose of your visit? 0:00:36.280 --> 0:00:38.640 Roger that Mustard Seed. I have two hundred and fifty 0:00:38.640 --> 0:00:41.440 Shakespeare enthusiast on board, just waking up for a tour 0:00:41.479 --> 0:00:44.680 of the Uranian Moons. Our visit to the Royal Automated 0:00:44.800 --> 0:00:47.680 Uranian Theater on Titanius should be registered in the log. 0:00:48.440 --> 0:00:53.159 All right, Roger that USSHFG. I can confirm your reservation 0:00:53.320 --> 0:00:57.520 now and docking credentials are good to go with your passengers, 0:00:57.560 --> 0:01:00.680 a pleasant and safe visit to the Uranian satellite system. 0:01:00.800 --> 0:01:05.920 The next Automated Thespianoid performance will be let's see Ooh 0:01:06.160 --> 0:01:08.640 Edward the third Well, better luck next time. 0:01:13.040 --> 0:01:16.800 Welcome to Stuff to Blow your Mind. The production of iHeartRadio. 0:01:22.920 --> 0:01:25.000 Hey you welcome to Stuff to blow your mind. My 0:01:25.120 --> 0:01:25.920 name is Robert. 0:01:25.760 --> 0:01:28.800 Lamb and I'm Joe McCormick, and we're back with part 0:01:28.840 --> 0:01:33.959 two of our series on the planet Uranus and its moons. Now, 0:01:34.000 --> 0:01:37.919 in part one we focused mainly on the planet itself. 0:01:38.000 --> 0:01:41.600 This time we're going to start getting more into the moons. 0:01:41.680 --> 0:01:43.800 Maybe we'll do all of the moons this time. I 0:01:43.800 --> 0:01:46.360 think last time we promised it would happen. We'll see 0:01:46.440 --> 0:01:48.360 whether we can fit it all into one episode. But 0:01:49.120 --> 0:01:52.120 I had a few more core planet digressions burning a 0:01:52.160 --> 0:01:54.720 hole in my pocket that I wanted to mention before 0:01:54.760 --> 0:01:57.800 we fly off to the satellites. Are you okay with that, rob. 0:01:57.800 --> 0:01:58.320 Let's do it. 0:01:58.760 --> 0:02:01.520 So. First of all, I was wondering what's the density 0:02:01.560 --> 0:02:05.120 of Uranus, And it turns out that Uranus is the 0:02:05.160 --> 0:02:09.119 second least dense planet in the Solar System at one 0:02:09.120 --> 0:02:12.920 point twenty seven grams per cubic centimeter. The only planet 0:02:13.040 --> 0:02:16.040 less dense is actually Saturn, the second largest planet in 0:02:16.040 --> 0:02:19.919 the Solar System. You might wonder which planet is the densest, Baby, 0:02:20.040 --> 0:02:23.040 that's Earth. That's Earth. We are at five point five 0:02:23.080 --> 0:02:25.480 to one grams per cubic centimeter, so we are the 0:02:25.520 --> 0:02:28.960 density king. But one of the real things I wanted 0:02:28.960 --> 0:02:32.720 to return to was a question of materials, because in 0:02:32.760 --> 0:02:35.880 the last episode we mentioned, just giving sort of an 0:02:35.880 --> 0:02:40.040 overview of the basics of the planet, that most of 0:02:40.120 --> 0:02:43.799 the mass of Uranus is thought to be a hot, 0:02:44.360 --> 0:02:49.520 dense fluid of ices, probably surrounding a rocky core of 0:02:49.560 --> 0:02:52.760 some sort. And though it might be kind of strange 0:02:52.760 --> 0:02:57.280 to hear like hot dense fluid of ices, that almost 0:02:57.320 --> 0:02:59.800 kind of doesn't make sense based on our definition of ice. 0:03:00.240 --> 0:03:02.000 And it's true that a lot of this ice is 0:03:02.040 --> 0:03:04.440 going to be different than the kind of ice we know. 0:03:04.720 --> 0:03:07.600 So I was reading more about this in an article 0:03:07.680 --> 0:03:11.920 by a planetary atmospheric scientist named Amy Simon, who is 0:03:11.960 --> 0:03:15.639 a senior researcher at NASA Goddard, and this was written 0:03:15.680 --> 0:03:18.680 for the magazine of the Planetary Society. The article is 0:03:18.680 --> 0:03:21.760 called the Realm of the Ice Giants, and one of 0:03:21.800 --> 0:03:25.839 the questions Simon addresses in this article is why are 0:03:26.160 --> 0:03:30.600 the planets Uranus and Neptune called ice giants as opposed 0:03:30.600 --> 0:03:35.080 to regular gas giants. It's because compared to regular gas 0:03:35.080 --> 0:03:38.280 giants like Jupiter and Saturn, Uranus and neptune are composed 0:03:38.320 --> 0:03:42.840 of a higher proportion of ice forming molecules like water 0:03:43.040 --> 0:03:47.200 and methane, though much of that so called ice is 0:03:47.240 --> 0:03:50.680 in a phase unfamiliar to us. On the surface of Earth, 0:03:51.080 --> 0:03:55.080 Simon writes, quote, ice giants are mostly water, probably in 0:03:55.120 --> 0:03:59.160 the form of a super critical fluid. The visible clouds 0:03:59.320 --> 0:04:03.840 likely consist of ice crystals with different compositions. So regarding 0:04:03.960 --> 0:04:09.680 supercritical fluid, a supercritical fluid doesn't behave exactly like a liquid, 0:04:09.800 --> 0:04:13.400 gas or a solid. It's an emergent state of matter 0:04:13.920 --> 0:04:18.080 occurring at temperatures and pressures beyond what is known as 0:04:18.120 --> 0:04:22.359 the critical point for each substance. And Simon has a 0:04:22.440 --> 0:04:26.280 very good paragraph clarifying the planetary science use of the 0:04:26.400 --> 0:04:29.320 term ice, which could help clear up any confusion there. 0:04:29.600 --> 0:04:32.200 She says that on Earth we usually use the term 0:04:32.279 --> 0:04:35.000 ice to refer to just water H two O when 0:04:35.040 --> 0:04:38.680 it is frozen solid, but planetary astronomers use the word 0:04:38.760 --> 0:04:43.719 ice to refer to any condensable molecule in its solid form. 0:04:44.040 --> 0:04:48.520 She writes, quote, These tend to be highly reflective form clouds, 0:04:48.560 --> 0:04:53.560 and unlike minerals, can readily change between liquid, solid and 0:04:53.680 --> 0:04:58.240 gas states at relatively low temperatures, so we're mainly familiar 0:04:58.279 --> 0:05:01.760 with water ice on the surf of Earth, but throughout 0:05:01.800 --> 0:05:06.479 space there are lots of ices. There's methane, ammonia, hydrogen sulfide, 0:05:06.560 --> 0:05:11.520 and phosphene pH three, and these are all condensable molecules 0:05:11.640 --> 0:05:15.240 and could all freeze in the atmosphere of Uranus and 0:05:15.440 --> 0:05:18.839 Neptune also for that matter, and Simon writes that most 0:05:18.839 --> 0:05:21.440 of the clouds we see in the atmospheres of these 0:05:21.480 --> 0:05:25.719 ice giants are clouds of methane ice crystals or hydrogen 0:05:25.800 --> 0:05:31.280 sulfide ice, So there's probably weird supercritical fluids down below, 0:05:31.360 --> 0:05:34.720 and then an atmosphere above. The atmosphere in its gas 0:05:34.720 --> 0:05:38.800 contents is mostly hydrogen and helium, but that atmosphere is 0:05:38.839 --> 0:05:42.200 probably full of traces of different kinds of ice, including 0:05:42.279 --> 0:05:46.000 not just H two O, but things like ammonia and methane. 0:05:46.520 --> 0:05:50.560 And speaking of methane, as we mentioned last time, the 0:05:50.600 --> 0:05:54.840 blue color of both Neptune and Uranus appears to come 0:05:54.880 --> 0:05:58.480 from the presence of methane in their atmospheres, which absorbs 0:05:58.560 --> 0:06:02.680 the red wavelength of light from the sun and reflects 0:06:02.720 --> 0:06:06.560 only the blue spectrum. But the question is why is 0:06:06.720 --> 0:06:09.880 Urinus a paler shade of blue than Neptune. If you 0:06:09.920 --> 0:06:12.279 look at Neptune, it's often kind of a royal blue, 0:06:12.320 --> 0:06:16.440 whereas in true color, Urinus appears kind of a gray 0:06:16.560 --> 0:06:20.480 green blue. Simon writes that this is quote either because 0:06:20.680 --> 0:06:24.200 Urinus has more haze, so more kind of a cloudy 0:06:24.279 --> 0:06:28.440 outer shell, but she goes on, or because Neptune's atmosphere 0:06:28.480 --> 0:06:34.000 has another unidentified constituent that absorbs longer wavelength light even 0:06:34.120 --> 0:06:37.160 more strongly, and of course longer wavelength light would be 0:06:37.480 --> 0:06:41.119 more red shifted toward the red end of the visible spectrum. Okay, 0:06:41.160 --> 0:06:44.239 so that's ice, the atmosphere, the makeup of the planet. 0:06:44.279 --> 0:06:46.600 But there's one more thing you may have seen headlines 0:06:46.640 --> 0:06:50.240 about regarding Urinus in Neptune that if you have seen 0:06:50.279 --> 0:06:52.880 these headlines, I'm sure you're wondering about it, and that 0:06:53.040 --> 0:06:56.359 is the claim that some experts have argued that it 0:06:56.560 --> 0:07:02.159 likely rains diamonds on Urine Neptune, and from what I 0:07:02.200 --> 0:07:05.560 can tell, this is true. Now, this is obviously something 0:07:05.600 --> 0:07:09.760 we haven't been able to detect directly with probes or anything, 0:07:10.040 --> 0:07:14.120 so nobody can sense this happening. Instead, it's based on 0:07:14.280 --> 0:07:17.160 what we do know about the planets and argue and 0:07:17.200 --> 0:07:21.000 sort of extrapolating logically from those starting facts. So how 0:07:21.000 --> 0:07:23.720 does the logic go? Well, I was reading about this 0:07:23.840 --> 0:07:27.120 in an article for space dot com by the sunny 0:07:27.120 --> 0:07:31.720 Stonybrook astrophysicist Paul Im Sutter, and in this article, Sutter 0:07:31.800 --> 0:07:36.200 explains that we know from mathematical models that the inner 0:07:36.440 --> 0:07:40.920 mantles of ice giants probably have temperatures of about seven 0:07:41.000 --> 0:07:45.440 thousand kelvins or over sixty seven hundred celsius and pressure 0:07:45.560 --> 0:07:49.520 about six million times the atmospheric pressure on the surface 0:07:49.520 --> 0:07:53.080 of Earth. Meanwhile, higher up in the mantle, things are 0:07:53.120 --> 0:07:57.400 cooler about two thousand kelvins and only two hundred thousand 0:07:57.440 --> 0:08:01.920 times Earth's atmospheric pressure. And we know that water, ammonia, 0:08:02.000 --> 0:08:05.440 and methane are present within that mantle. So what happens 0:08:05.480 --> 0:08:10.280 to those substances in those conditions. Well, these conditions of 0:08:10.280 --> 0:08:15.840 temperature and pressure would tend to tear apart molecules of methane, methane, 0:08:15.880 --> 0:08:20.520 is ch four carbon, and hydrogen. And when those molecules 0:08:20.520 --> 0:08:24.040 get torn apart, we are left with free carbon. Free 0:08:24.080 --> 0:08:28.040 carbon tends to link together with other free carbon to 0:08:28.160 --> 0:08:32.160 form long chains of carbon what happens to long chains 0:08:32.200 --> 0:08:36.080 of pure carbon under high pressure that gets pressed into 0:08:36.240 --> 0:08:40.040 a diamond. These diamonds would tend to then drop down 0:08:40.120 --> 0:08:44.080 to lower in the mantle where high temperatures vaporize them, 0:08:44.240 --> 0:08:47.040 and then they float back up into the upper mantle, 0:08:47.120 --> 0:08:50.800 and then the cycle repeats, so you're left with diamond rain. 0:08:51.480 --> 0:08:54.680 Sounds like the name of a great alternate universe collaborative 0:08:54.760 --> 0:08:58.000 sci fi movie musical between Prince and David Bowie. Wish 0:08:58.000 --> 0:09:00.400 I could have seen it, but it does to be 0:09:00.600 --> 0:09:04.400 very likely a physical reality on Uranus and Neptune as well. 0:09:05.160 --> 0:09:08.160 So you're saying that all we have to do is 0:09:08.720 --> 0:09:13.040 jet out to Uranus, dip down into the atmosphere of Uranus, 0:09:13.240 --> 0:09:16.520 scoop up some diamonds, then get back to Earth and 0:09:16.559 --> 0:09:17.559 we're set for life. 0:09:17.880 --> 0:09:20.000 I've always said when I look up at the stars 0:09:20.040 --> 0:09:25.160 at night, what I see is profit. Okay, but one 0:09:25.160 --> 0:09:28.760 more digression before we get to the moons. Since part one, 0:09:28.840 --> 0:09:31.480 we actually got a really great bit of listener mail 0:09:31.679 --> 0:09:34.600 from Joe, not me, but a different Joe who listens 0:09:34.640 --> 0:09:38.160 to the show, who brought to our attention some really 0:09:38.200 --> 0:09:41.760 awesome photos of Uranus recently captured by the James web 0:09:41.800 --> 0:09:46.000 Space Telescope. Joe writes, quote, I've long awaited with tremulous 0:09:46.040 --> 0:09:50.240 anticipation the resumption of your ural journey to the heliopause, 0:09:50.559 --> 0:09:53.520 and was thrilled to see the recumbent sky king Uranus 0:09:53.600 --> 0:09:57.240 on my podcast feed. Your choice was timely, indeed, as 0:09:57.280 --> 0:10:00.560 the James Webb Space Telescope just last month least some 0:10:00.720 --> 0:10:05.480 spectacular visuals of Uranus. These images boast greater clarity than 0:10:05.480 --> 0:10:08.920 the Hubble's effort, especially of the planet's rings. I love 0:10:09.040 --> 0:10:11.200 living under a sky that will never run out of 0:10:11.200 --> 0:10:13.960 extraordinary things to look at and talk about, and I 0:10:14.000 --> 0:10:18.520 appreciate when you cast your gaze upward from time to time. Joe, Well, 0:10:18.520 --> 0:10:20.720 thank you, Joe. Because I had not seen these, I 0:10:20.760 --> 0:10:24.320 looked them up and this is fantastic. So I saw 0:10:24.360 --> 0:10:28.080 these within the context of a NASA press release from 0:10:28.160 --> 0:10:31.079 April sixth, twenty twenty three that Joe shared with us 0:10:31.640 --> 0:10:34.640 Rob I pasted these two photos here in the outline. 0:10:34.679 --> 0:10:37.280 One is just zoomed in on the planet from the 0:10:37.320 --> 0:10:40.880 more zoomed out second one. I would say, from my perspective, 0:10:41.320 --> 0:10:45.520 these images are gorgeous. They fill one with awe at 0:10:45.520 --> 0:10:48.679 the picture of this frosty, dark recess where the blue 0:10:48.679 --> 0:10:52.120 God lives. And this might sound a little bit weird, 0:10:52.400 --> 0:10:55.120 but I actually mean this in the best possible way. Somehow, 0:10:55.160 --> 0:10:59.920 in these images, Urinus looks more like an optical artifact 0:11:00.360 --> 0:11:03.960 than a physical object, as if the planet were like 0:11:04.120 --> 0:11:08.280 a glint or a lens flare. And to explain what 0:11:08.320 --> 0:11:10.920 I mean, so the planet is pictured on its side, 0:11:11.000 --> 0:11:13.920 because of course that's how it is. We're not seeing 0:11:13.920 --> 0:11:17.520 the rings laterally from the side, crossing over and behind 0:11:17.600 --> 0:11:20.760 the planet, like we do in most photos of Saturn. Instead, 0:11:20.800 --> 0:11:24.079 we're seeing the rings encircling the planet in an egg 0:11:24.120 --> 0:11:27.920 shape because we're looking roughly down toward the north pole, 0:11:28.800 --> 0:11:33.280 which faces sideways. And in this particular photo, though this 0:11:33.400 --> 0:11:37.000 is not exactly true color, the planet is pale blue 0:11:37.000 --> 0:11:40.360 with a white cap, and the rings sort of fade 0:11:40.520 --> 0:11:45.360 outward to inward, from a screaming fluorescent white to a 0:11:45.559 --> 0:11:49.320 dim blue gray as they sink toward the planet's atmosphere. 0:11:49.960 --> 0:11:53.120 And the sunlight seems blinding in these images because we 0:11:53.160 --> 0:11:55.880 actually see it gleaming off the edge of the planet. 0:11:55.920 --> 0:11:58.959 Which is even weirder because, as I said, the disk 0:11:59.040 --> 0:12:01.840 of Urinus facing us looks like a glint or a 0:12:01.880 --> 0:12:04.920 gleam itself, and in the more zoomed out of these 0:12:04.960 --> 0:12:07.480 two photos, we can see the blue dots of the 0:12:07.559 --> 0:12:11.360 larger moons surrounding it, also sending out these sort of 0:12:11.400 --> 0:12:15.360 shafts of reflected light in these hexagonal criss crosses out 0:12:15.360 --> 0:12:15.960 into space. 0:12:16.480 --> 0:12:19.280 Yeah, these images are gorgeous. It makes it look like. 0:12:19.480 --> 0:12:25.920 Urinus is a planet designed by Japanese illustrator Hajimi Soriyama, whose, 0:12:25.960 --> 0:12:28.560 of course I think he worked on the design for 0:12:28.600 --> 0:12:35.120 the original Sony Aibo robot, but also mostly known for 0:12:36.559 --> 0:12:40.960 robot pin up like really shiny, silvery robot pin up models. 0:12:42.160 --> 0:12:44.640 This artist is on my mind because the movie we're 0:12:44.679 --> 0:12:48.480 watching Friday in for Weird House Cinema, this artist is 0:12:48.559 --> 0:12:51.520 credited like deep down in the credits because there's a 0:12:51.600 --> 0:12:53.480 character in the movie that has some of this art 0:12:53.640 --> 0:12:58.120 up on his workstation. But this kind of but there's 0:12:58.160 --> 0:13:03.280 a certain from the female robot bodies in his art. 0:13:03.320 --> 0:13:07.079 There is this kind of like glimmering like silvery perfection 0:13:07.240 --> 0:13:10.560 to things, And that's what I kind of get from 0:13:10.600 --> 0:13:13.560 this image of Urinus. And if you're into planets, like 0:13:13.640 --> 0:13:15.240 I mean, put it on a calendar. It looks, it 0:13:15.280 --> 0:13:16.359 looks nice. 0:13:16.200 --> 0:13:18.280 It is beautiful, And I will say the blue in 0:13:18.320 --> 0:13:21.280 this photo, as I alluded to, is not exactly true 0:13:21.320 --> 0:13:24.800 color from the visible spectrum. I think it's approximate. So 0:13:25.120 --> 0:13:28.720 the image is from the webs near infrared camera, combining 0:13:28.800 --> 0:13:32.360 data from two filters. According to the press release, it 0:13:32.440 --> 0:13:35.760 was one point four and three point oh microns, and 0:13:35.800 --> 0:13:38.439 then the article explains these are coded out to blue 0:13:38.440 --> 0:13:43.320 and orange respectively. Now I mentioned the white cap that 0:13:43.360 --> 0:13:47.400 we see on Urinus in this photo. The article explains 0:13:47.440 --> 0:13:49.880 that this is known as the polar cap, and it 0:13:49.920 --> 0:13:53.520 seems to manifest when the pole of the planet goes 0:13:53.559 --> 0:13:57.400 into direct sunlight during its long polar summer, which again, 0:13:58.000 --> 0:14:00.680 as we talked about last time, lasts many years at 0:14:00.720 --> 0:14:03.480 a time, and then the cap seems to disappear in 0:14:03.520 --> 0:14:06.240 the fall when it starts to turn away from the sun. 0:14:06.840 --> 0:14:09.120 As far as I could find, we aren't sure exactly 0:14:09.160 --> 0:14:11.520 what causes this, or maybe if somebody knows, I just 0:14:11.559 --> 0:14:15.160 didn't dig that up. But so regarding the beautiful rings 0:14:15.200 --> 0:14:19.600 in the picture, Uranus has thirteen known rings, and you 0:14:19.680 --> 0:14:22.720 can see eleven of them in this photo, though some 0:14:22.760 --> 0:14:25.520 of them are so bright that they bleed together. In 0:14:25.560 --> 0:14:28.480 the image, there are nine major rings, and then there 0:14:28.480 --> 0:14:31.400 are two kind of faint dusty rings that were discovered 0:14:31.480 --> 0:14:34.280 during the approach and Voyager two in nineteen eighty six. 0:14:34.760 --> 0:14:38.360 But speaking of those rings and moons, rings and moons 0:14:38.760 --> 0:14:42.000 sometimes have an interesting origin story, So I was wondering 0:14:42.480 --> 0:14:45.840 where do experts generally think they came from in the 0:14:45.880 --> 0:14:49.240 case of Uranus. Going back to that Planetary Society article 0:14:49.320 --> 0:14:53.000 by Amy Simon, Simon writes that the medium sized moons 0:14:53.000 --> 0:14:57.440 of Uranus probably formed in place at the same time 0:14:57.760 --> 0:15:02.240 or after whatever event it was that left Uranus tilted 0:15:02.280 --> 0:15:04.440 on its side. And as we talked about last time, 0:15:04.560 --> 0:15:07.960 it seems likely that Uranus was probably knocked on its 0:15:08.000 --> 0:15:11.560 side and left colder than all the other planets because 0:15:11.600 --> 0:15:14.520 of an impact with a large object, maybe like an 0:15:14.560 --> 0:15:18.520 Earth sized planet, billions of years ago. And so what 0:15:18.560 --> 0:15:22.480 we're left with is that the moon's orbit Urinus on 0:15:22.520 --> 0:15:26.120 its equatorial plane, So like the planet itself and like 0:15:26.160 --> 0:15:30.240 its rings, the moons are tilted at a roughly ninety 0:15:30.240 --> 0:15:33.720 degree angle to the rest of the Solar System. In general, 0:15:33.800 --> 0:15:36.120 the moons of Urinus are made of ice and rock, 0:15:36.560 --> 0:15:40.200 usually slightly more ice than rock, and they show some 0:15:40.400 --> 0:15:44.440 interesting surface features, like patterns of darkening on their surfaces 0:15:44.480 --> 0:15:49.400 that are caused by some unknown material. Spectral analysis reveals 0:15:49.440 --> 0:15:52.600 the presence of frozen carbon dioxide on a lot of 0:15:52.640 --> 0:15:57.160 the moons. Meanwhile, the origin of the rings, the consensus 0:15:57.160 --> 0:16:01.840 seems to be that they are created by the shattering 0:16:01.960 --> 0:16:06.800 into dust and fragments of formerly solid moons. And as 0:16:06.840 --> 0:16:10.360 we've seen with other planets, the sudden or gradual smash 0:16:10.480 --> 0:16:13.480 up of moons can happen a number of ways, by 0:16:13.840 --> 0:16:17.840 you know, lots of little collisions with meteoroids or other objects, 0:16:17.920 --> 0:16:21.120 or by tidal breakup due to gravity, in any case, 0:16:21.200 --> 0:16:26.960 turning former larger satellites into smaller satellites and rings of 0:16:27.080 --> 0:16:27.960 little fragments. 0:16:28.320 --> 0:16:32.080 Yeah, it's fascinating. How from our human perspective we look 0:16:32.160 --> 0:16:34.560 up at our moon, we consider the moons of other worlds, 0:16:34.600 --> 0:16:37.040 and there's a certain certain stability to them, you know. 0:16:38.040 --> 0:16:43.400 But if you look at any planets, moons or moon, 0:16:44.840 --> 0:16:49.320 generally you're looking at a more violent relationship over the 0:16:49.840 --> 0:16:55.720 vast history of a given planet. There's nothing peaceful about it. 0:17:03.240 --> 0:17:06.879 All right, Well, let's begin, at least begin to dip 0:17:06.960 --> 0:17:10.480 into the moons of Uranus. Like I said, we originally 0:17:10.480 --> 0:17:11.919 set out to do them all. Maybe we won't do 0:17:11.960 --> 0:17:14.639 them all. Maybe we'll get part way through the journey 0:17:14.680 --> 0:17:18.360 and we'll come back on Tuesday. Who knows, maybe we'll 0:17:18.400 --> 0:17:20.600 just we'll just get into we'll finish them up, and 0:17:20.600 --> 0:17:23.920 then we'll go right into Neptune. There are no rules. 0:17:23.960 --> 0:17:26.760 We can do what we want. So let's start with 0:17:26.760 --> 0:17:30.320 the inner moons of Uranus. Thirteen total known. All right, 0:17:30.359 --> 0:17:33.600 We're going to start with a pair of moons, Cordelia 0:17:33.680 --> 0:17:38.000 and Ophelia. These are named for the youngest daughter of 0:17:38.080 --> 0:17:43.600 King Lear and of course Hamlet's tragic beloved, respectively. The 0:17:43.640 --> 0:17:47.560 main significance of these moons is that both Cordelia and 0:17:47.600 --> 0:17:52.159 Ophelia are shepherd moons, as their gravity keeps Uranus's epsilon 0:17:52.320 --> 0:17:53.720 ring from dispersing. 0:17:53.960 --> 0:17:56.439 Now I thought this was interesting, so I was looking 0:17:56.520 --> 0:18:00.480 up how exactly it is that shepherd moons work. What 0:18:00.520 --> 0:18:04.560 does the shepherd moon do? These little small moons, how 0:18:04.600 --> 0:18:08.440 do they keep a ring? Essentially, they keep a ring 0:18:08.600 --> 0:18:12.240 in tight formation around the planet and clear these gaps 0:18:12.280 --> 0:18:15.800 between the rings. And it seems that essentially it works 0:18:15.840 --> 0:18:18.880 like this. So you've got a small moon and it's 0:18:19.000 --> 0:18:21.960 orbiting the planet, And imagine at first it's orbiting the 0:18:21.960 --> 0:18:26.880 planet along with a bunch of other small particles sort 0:18:26.880 --> 0:18:31.200 of within the lane of that small moon's orbit. Particles 0:18:31.280 --> 0:18:35.640 that are ahead of the small moon will be attracted 0:18:35.880 --> 0:18:39.920 by gravity to it, meaning if they're orbiting ahead of it, 0:18:39.960 --> 0:18:42.960 they will naturally want to slow down in their orbit, 0:18:43.040 --> 0:18:47.280 right because they're getting pulled toward this moon. But slowing 0:18:47.320 --> 0:18:50.560 down in their orbit actually causes them to lose energy 0:18:51.000 --> 0:18:54.360 and fall down closer to the planet that they're orbiting. 0:18:54.440 --> 0:18:56.720 So these like dust and particles and things in the 0:18:56.800 --> 0:19:03.679 ring actually end up sorting into lower orbit rings. And 0:19:03.720 --> 0:19:07.639 then meanwhile, things that are orbiting along the same lane 0:19:07.760 --> 0:19:10.800 as this moon that are behind it in its orbit 0:19:10.920 --> 0:19:14.560 are attracted to it and thus sped up. And as 0:19:14.600 --> 0:19:18.280 they get sped up during to chase after this moon 0:19:18.359 --> 0:19:21.720 by the force of gravity, that acceleration actually causes them 0:19:21.760 --> 0:19:24.920 to have greater energy and to ascend in their orbit 0:19:25.240 --> 0:19:28.840 and end up going into outer rings beyond that little moon. 0:19:29.720 --> 0:19:32.320 So again we have the Shepherd moons here. They were 0:19:32.359 --> 0:19:36.199 discovered by Voyager two in nineteen eighty six. Like the 0:19:36.200 --> 0:19:38.440 rest of Uranus's inner moons. They appear to be roughly 0:19:38.440 --> 0:19:42.600 equal split of water, ice and rock. They're small. Of 0:19:42.680 --> 0:19:46.560 note to Cordelia is the closest to the planet, and 0:19:46.880 --> 0:19:49.879 I guess we should also point out or come back 0:19:49.920 --> 0:19:53.719 to the fact that, yes, these are both Shakespearean references. 0:19:53.880 --> 0:19:56.600 There are going to be a lot of shakespeare references 0:19:56.680 --> 0:19:59.880 as we go through the moons of Uranus and these 0:20:00.160 --> 0:20:00.800 just the first two. 0:20:01.040 --> 0:20:03.640 It seems that a lot of the names of these satellites, 0:20:03.720 --> 0:20:06.040 for some reason were chosen either from the works of 0:20:06.080 --> 0:20:09.760 Shakespeare or from the works of Alexander Pope. 0:20:10.280 --> 0:20:15.000 Yeah, predominantly Shakespearean, but definitely there's some key Alexander Pope 0:20:15.040 --> 0:20:17.359 references as well. So as as we go through it, 0:20:17.400 --> 0:20:19.399 we're we'll probably talk a little bit about some of 0:20:19.440 --> 0:20:21.160 the namesakes here. 0:20:21.400 --> 0:20:23.639 Well, this was something I was wondering. I don't know 0:20:23.720 --> 0:20:26.919 about the origin exactly, like what people had in mind 0:20:26.960 --> 0:20:30.280 when they were naming these, but so I think, like, 0:20:30.440 --> 0:20:34.840 is there some significance to the innermost minor moon here 0:20:35.280 --> 0:20:40.159 being called Cordelia, Because Cordelia is a very poignant character. 0:20:40.440 --> 0:20:43.800 Cordelia is the youngest daughter of King Lear in the 0:20:43.840 --> 0:20:45.760 play King Lear. If you don't know the play or 0:20:45.800 --> 0:20:48.679 need refreshing the very beginning of it. The first scene 0:20:48.920 --> 0:20:52.280 is King Lear is this old king? He comes out. 0:20:52.320 --> 0:20:55.119 He decides that he will divide up his kingdom between 0:20:55.160 --> 0:20:59.960 his three daughters, Goneril, Reagan, and Cordelia, and he's gonna 0:21:00.040 --> 0:21:03.639 give the largest portion to the daughter that loves him most. 0:21:03.840 --> 0:21:08.240 So Goneril and Reagan give these speeches where they overwhelm 0:21:08.320 --> 0:21:11.919 their father with absurd insincere flattery about how much they 0:21:11.960 --> 0:21:15.320 love him. And then when it's Cordelia's time to speak, 0:21:15.400 --> 0:21:19.879 she finds that she cannot put into words. She cannot 0:21:19.960 --> 0:21:23.720 express her love for her father to herself. She says 0:21:23.760 --> 0:21:26.480 that she knows her love is richer than her tongue. 0:21:26.880 --> 0:21:28.840 And then when it's her time to speak, she says, 0:21:28.920 --> 0:21:32.000 unhappy that I am. I cannot heave my heart into 0:21:32.040 --> 0:21:35.439 my mouth. I love your majesty according to my bond, 0:21:35.920 --> 0:21:39.280 no more nor less, and I think he gives her 0:21:39.280 --> 0:21:42.159 a chance to amend her statement. She doesn't, really, and 0:21:42.200 --> 0:21:46.159 the so Leir gets furious at this decides to disinherit her. 0:21:46.240 --> 0:21:49.879 He gives nothing to Cordelia, splits his kingdom between the 0:21:49.920 --> 0:21:53.600 other two daughters, Goneril and Reagan who secretly think he 0:21:53.720 --> 0:21:55.720 is a fool, and they will go on to betray 0:21:55.800 --> 0:21:58.640 him once they come to power, And of course it's 0:21:58.640 --> 0:22:01.199 a tragedy, so things just get worse and worries. Basically 0:22:01.280 --> 0:22:04.240 everybody ends up dead. But you know, it's a very 0:22:04.280 --> 0:22:07.240 meaningful character and something I think, I don't know that 0:22:07.400 --> 0:22:09.760 that moment in the first scene is something that always 0:22:09.800 --> 0:22:12.440 got me, something I can really relate to, like the 0:22:12.480 --> 0:22:18.720 feeling of worrying that you don't express positive feelings because 0:22:18.760 --> 0:22:22.320 you're afraid that you can't phrase them in the sincerest way, 0:22:22.400 --> 0:22:24.080 like you don't know how to put them to words. 0:22:24.080 --> 0:22:26.680 So then you worry that like you're perceived as not 0:22:26.720 --> 0:22:28.800 wanting to say a positive thing at all. I don't 0:22:28.800 --> 0:22:30.040 know if that makes sense. 0:22:30.760 --> 0:22:32.760 No, no, no, no, I mean certainly with the example 0:22:34.119 --> 0:22:36.679 here from the play, absolutely. 0:22:36.480 --> 0:22:39.679 But she's the daughter that truly loved him. She just 0:22:40.000 --> 0:22:43.959 you know, didn't want to give a big, insincere speech. Anyway, 0:22:44.000 --> 0:22:46.040 It's a very meaningful character. So I'm wondering, is there 0:22:46.119 --> 0:22:48.480 some similarly at play here in the selection of the 0:22:48.560 --> 0:22:50.520 name for this moon? Maybe not so, Like it's a 0:22:50.640 --> 0:22:54.480 very small satellite, it's the closest to the planet of these. 0:22:54.680 --> 0:22:57.800 It is one of the shepherd moons that sort of 0:22:58.200 --> 0:23:01.720 guide guides the epsilon and keeps it tight in formation. 0:23:02.720 --> 0:23:05.440 By the end, I mean, she does show great discipline 0:23:05.480 --> 0:23:08.560 because she comes back with an army to try to 0:23:08.560 --> 0:23:13.200 to fight on her father's side against her cruel, duplicitous sisters. 0:23:13.560 --> 0:23:15.720 I don't know, maybe not, I don't know if it fits, 0:23:15.760 --> 0:23:16.840 but I was wondering. 0:23:17.680 --> 0:23:21.560 No, I think it's natural to try and read some 0:23:21.600 --> 0:23:24.880 sort of sense into the naming. Though. Of course, as 0:23:24.920 --> 0:23:27.720 we'll discuss it, it's different people at different times coming 0:23:27.840 --> 0:23:30.520 up with these names. You know, some are maybe probably 0:23:30.520 --> 0:23:33.760 a little more up on the works of William Shakespeare 0:23:33.760 --> 0:23:37.359 than others. Sometimes there seems like something they could be getting, 0:23:37.400 --> 0:23:40.320 at other times not. And also some of these kind 0:23:40.359 --> 0:23:44.639 of slip by on a technicality, so they're kind of 0:23:44.680 --> 0:23:47.040 all over the place. All right, let's let's go into 0:23:47.080 --> 0:23:50.600 the next one. There's a Bianca named after Kate's sister 0:23:50.840 --> 0:23:54.800 in the Taming of the Shrew. This one does nothing 0:23:54.840 --> 0:23:57.280 really else that I think is significant about it, and 0:23:57.320 --> 0:24:00.280 it was also discovered by voyager two. All right, after that, 0:24:00.320 --> 0:24:03.200 we have Cresida. This is the title character from Troylus 0:24:03.240 --> 0:24:07.560 and Cressida. Again, nothing other else. It's really significant about 0:24:07.560 --> 0:24:10.879 this moon. It was also discovered by Voyger two. I 0:24:10.880 --> 0:24:12.679