WEBVTT - How do planets get rings? 0:00:08.480 --> 0:00:10.520 Pee Katie, help me out with some research for an 0:00:10.600 --> 0:00:13.560 upcoming episode. Alright, as long as you don't put me 0:00:13.560 --> 0:00:16.600 in that collider of yours. Not this time, but you know, 0:00:16.680 --> 0:00:19.759 in general, no promises, so just make sure you always 0:00:19.800 --> 0:00:22.880 read the waiver very carefully. All right, I'll wear a helmet. 0:00:23.000 --> 0:00:26.920 So what are we researching? Well, I'm trying to understand rings, 0:00:27.280 --> 0:00:30.720 all right, and how can I help? Well, you got 0:00:30.760 --> 0:00:34.519 engaged and married recently, didn't you. Yeah, during the pandemic. 0:00:34.680 --> 0:00:37.880 I had a zoom wedding. It was It was really fun. 0:00:38.080 --> 0:00:40.080 And did you get a real ring or a digital 0:00:40.159 --> 0:00:44.120 zoom ring? I got a real ring, not just an 0:00:44.240 --> 0:00:46.640 n f T pointing tour ring. Yes, I have a 0:00:46.720 --> 0:00:49.080 real ring. And tell us a little bit about it. 0:00:49.120 --> 0:00:52.240 Is it made out of icy particles or mostly dust 0:00:52.280 --> 0:00:55.200 and rocks. It was actually grown in a lab lab 0:00:55.240 --> 0:00:58.880 grown diamonds, which is pretty neat to me. Well, I 0:00:58.960 --> 0:01:03.400 wonder if castor and planetary rings have anything in common. Yeah, 0:01:03.520 --> 0:01:07.840 I wonder the same thing. You know. Actually, my husband 0:01:07.959 --> 0:01:10.080 later told me that he had the choice to get 0:01:10.120 --> 0:01:14.040 like a ring made out of a meteorite, So sometimes 0:01:14.160 --> 0:01:16.720 they do converge. While it'd be awesome a little bit 0:01:16.720 --> 0:01:21.960 of space on your finger. Well, we will have to 0:01:22.040 --> 0:01:25.520 invite Saturn on the podcast to ask how it got 0:01:25.560 --> 0:01:30.720 its rings and when it's fiance proposed to it. Saturn's 0:01:30.720 --> 0:01:49.120 got the best bling in the Solar system. Hi, I'm Daniel. 0:01:49.200 --> 0:01:52.240 I'm a physicist at UC Irvine and I do research 0:01:52.320 --> 0:01:56.160 at the Large Hadron Collider. I am Katie Golden. I 0:01:56.240 --> 0:02:00.320 host Creature Feature, a biology podcast, So I'm not actually 0:02:00.360 --> 0:02:03.680 a physicist, but I have used a hula hoop before, 0:02:03.800 --> 0:02:07.760 so I feel fairly confident I can talk about Saturn's 0:02:07.840 --> 0:02:10.359 rings today. Oh. I think that makes you an engineer, 0:02:10.440 --> 0:02:13.960 doesn't it. That's right, Just get me some tape and 0:02:14.160 --> 0:02:19.200 a few paper clips, and boom, I'm an engineer. Well, 0:02:19.240 --> 0:02:21.240 I actually don't wear a whole lot of rings. I 0:02:21.280 --> 0:02:24.080 just have this one wedding ring, which my wife and 0:02:24.080 --> 0:02:26.160 I picked up two days before our wedding on the 0:02:26.160 --> 0:02:29.079 streets of Berkeley for about five bucks. And I think 0:02:29.080 --> 0:02:31.480 at the time we were like, oh, this will work temporarily, 0:02:31.600 --> 0:02:34.160 and here we are twenty years later, I'm still wearing 0:02:34.160 --> 0:02:37.480 the same silver ring. No, that's so sweet. I love 0:02:37.520 --> 0:02:39.760 that story. Yeah, it's a nice memory. It helps me 0:02:39.840 --> 0:02:41.960 understand where I came from. And you know, in the 0:02:42.000 --> 0:02:44.120 same way, we can look up at the night sky 0:02:44.480 --> 0:02:47.359 and study the planets and use their rings to try 0:02:47.400 --> 0:02:49.520 to get an idea of like where they came from, 0:02:49.560 --> 0:02:51.959 what is the history of this planet? How did it 0:02:52.080 --> 0:02:54.400 get that ring? Who gave it to it? And you know, 0:02:54.600 --> 0:02:56.839 what is that wedding going to look like? So you're 0:02:56.840 --> 0:02:59.680 saying because my ring was made in a lab, that 0:02:59.760 --> 0:03:02.560 I two was made in a lab. Maybe your love 0:03:02.680 --> 0:03:04.520 was grown in the lab, you know, which doesn't make 0:03:04.560 --> 0:03:07.200 it any less authentic. I'm a big fan of labs 0:03:07.200 --> 0:03:14.080 and research. It's very romantic test tube romance and welcome 0:03:14.120 --> 0:03:17.840 to the podcast. Daniel and Jorge explain the universe in 0:03:17.880 --> 0:03:21.200 which we try to grow your understanding of the nature 0:03:21.320 --> 0:03:24.400 of this universe that we find ourselves and we cast 0:03:24.400 --> 0:03:27.560 our minds out into the deepest darkness of space and 0:03:27.600 --> 0:03:30.919 try to ring out understanding of everything that's out there 0:03:30.960 --> 0:03:33.720 in the universe, and we zoom on into the tiniest 0:03:33.760 --> 0:03:37.520 little things between our toes and under our fingernails, because 0:03:37.520 --> 0:03:40.480 we want to understand the fundamental nature of the universe, 0:03:40.680 --> 0:03:43.600 the nature of space and time itself, and matter and 0:03:43.840 --> 0:03:46.960 energy and all those tiny little bits which, in their 0:03:47.000 --> 0:03:49.600 two ing and frowing, come together to make the universe 0:03:49.640 --> 0:03:52.200 that we know and love. My friend and co host 0:03:52.280 --> 0:03:54.760 Jorge can't be with us today he is on vacation, 0:03:54.840 --> 0:03:57.400 but we are very pleased to have the be Ringed, 0:03:57.520 --> 0:04:01.880 be Jeweled, be Blinged Kiti two join this today. Well, 0:04:01.880 --> 0:04:05.760 thank you for ringing me up for this episode. Yes, 0:04:05.880 --> 0:04:09.840 I'm very excited. I love science, but that doesn't mean 0:04:09.920 --> 0:04:14.960 I can't appreciate some good old fashioned cosmic jewelry. Well, 0:04:14.960 --> 0:04:16.840 one thing I love about jewelry is that it really 0:04:16.839 --> 0:04:19.640 does tell a story. You know, you talk to somebody 0:04:19.680 --> 0:04:22.520 and you see them with ear rings or with a necklace, 0:04:22.560 --> 0:04:24.840 you know that has a history. You know, maybe somebody 0:04:24.880 --> 0:04:27.240 bought for them, or they got it for some big event, 0:04:27.360 --> 0:04:29.440 or maybe they inherited it from their family, and it 0:04:29.440 --> 0:04:32.680 tells like an even deeper story about where they came 0:04:32.720 --> 0:04:35.839 from and their family history. So it's like everybody who's 0:04:35.839 --> 0:04:39.880 wearing jewelry is walking around telling little stories about themselves. Yeah, 0:04:39.880 --> 0:04:44.520 I love that. Or it bears an ancient curse? Are 0:04:44.520 --> 0:04:47.240 we going to take a deep dark turn on this podcast? 0:04:48.279 --> 0:04:51.040 I don't know. It is Saturn cursed? Is that where 0:04:51.040 --> 0:04:54.040 we're going to discover maybe Aliens visited the Solar System 0:04:54.080 --> 0:04:56.159 and had a war with the Octopi living under the 0:04:56.200 --> 0:04:59.000 oceans of Insulatus, and the rings are just the left 0:04:59.080 --> 0:05:03.640 over remnants that interstellar conflict. That's very spooky, and I 0:05:03.640 --> 0:05:06.279 would love that story for a ring that I had, 0:05:06.360 --> 0:05:09.080 that it was made by some kind of intergalactic war. 0:05:09.560 --> 0:05:12.680 I think it is one of the things about the 0:05:12.839 --> 0:05:16.520 Solar System that really adds a bit of magic to it, 0:05:16.560 --> 0:05:19.440 adds a bit of artistry to it, because of course 0:05:19.640 --> 0:05:23.120 I think all the planets are lovely, but they're all orbs, 0:05:23.240 --> 0:05:26.039 you know, they're they're all these roughly of course, not 0:05:26.160 --> 0:05:30.480 exact precise spears, but you know, roughly spherical. But then 0:05:30.560 --> 0:05:34.719 you have these rings. And it always when I see 0:05:34.839 --> 0:05:38.880 Saturn that gives me a feeling of awe about the 0:05:38.960 --> 0:05:42.920 mystery and artistry of space that I don't necessarily get 0:05:42.960 --> 0:05:46.560 with other planets, absolutely because it's so easy to grab onto, 0:05:46.640 --> 0:05:49.120 you know, it's so visible out there. And it must 0:05:49.160 --> 0:05:52.560 have been an amazing moment in sixteen ten when Galileo 0:05:52.720 --> 0:05:55.400 looked through his telescope and saw the rings of Saturn, 0:05:55.839 --> 0:05:58.920 and how shocking to discover that planets can have these 0:05:59.000 --> 0:06:01.800 incredible dis you know, these things are like ten times 0:06:01.800 --> 0:06:04.080 the size of Saturn. We'll talk later about how Saturday 0:06:04.160 --> 0:06:06.920 might have rings that go out like two hundred times 0:06:06.960 --> 0:06:10.040 the size of its radius. It's an incredible thing. Like 0:06:10.120 --> 0:06:12.640 I have this little tiny ring on my finger. Imagine 0:06:12.680 --> 0:06:14.560 if I was wearing a ring that was like two 0:06:14.680 --> 0:06:17.640 hundred times the size of me. You know, some might 0:06:17.680 --> 0:06:20.880 say that's a little overstated. It would be a statement piece, 0:06:20.920 --> 0:06:23.440 for sure. You know. I was actually just in the 0:06:23.480 --> 0:06:28.200 Galileo Museum in Florence, And when you think of Galileo 0:06:28.320 --> 0:06:31.280 with his telescope, he's often depicted with this small, you know, 0:06:31.520 --> 0:06:33.520 telescope he can hold in his hands. But you look 0:06:33.600 --> 0:06:37.120 at the actual telescopes he used to observe Saturn and 0:06:37.160 --> 0:06:40.839 they were huge. Yeah, he wasn't the inventor of the telescope, 0:06:40.880 --> 0:06:42.680 but he was the first one to really perfect it 0:06:42.720 --> 0:06:44.880 and then to turn it up on the skies, and 0:06:44.960 --> 0:06:47.480 so he got like the biggest first scoop of all 0:06:47.600 --> 0:06:49.880 these discoveries. You know, he saw the moons of Jupiter, 0:06:49.920 --> 0:06:52.560 he saw the rings of Saturn. He's on mountains on 0:06:52.600 --> 0:06:55.480 the Moon on a moment or like really look out 0:06:55.520 --> 0:06:57.279 into the universe. And I think that one of the 0:06:57.279 --> 0:06:59.400 most interesting things for me about it is that they 0:06:59.440 --> 0:07:02.200 do reve yield the history of the Solar System. You know, 0:07:02.240 --> 0:07:04.280 we look out unto the night sky and we want 0:07:04.320 --> 0:07:07.520 to understand not just what's out there, but why it's 0:07:07.560 --> 0:07:10.480 out there and why it looks the way that it does. 0:07:10.760 --> 0:07:13.600 And so anything that's weird or strange or unusual that's 0:07:13.600 --> 0:07:16.160 not just like a ball floating in the sky, Let's 0:07:16.200 --> 0:07:19.040 just ask the question, how did that get there? How 0:07:19.080 --> 0:07:21.440 long can that live? What does that tell us about 0:07:21.480 --> 0:07:24.040 the history of the Solar System? Have those rings just 0:07:24.120 --> 0:07:26.400 been there for the last million years? Have they been 0:07:26.440 --> 0:07:28.800 there since the beginning of the Solar System? Why do 0:07:28.880 --> 0:07:31.560 Saturn have rings and not other planets? Or do they right? 0:07:31.640 --> 0:07:34.480 There's just so many immediate questions that you can ask 0:07:34.520 --> 0:07:36.880 when you see these rings, and then those questions open 0:07:36.960 --> 0:07:39.680 the door to try to understand the formation of the 0:07:39.720 --> 0:07:42.760 Solar System. The other aspect, which is super fascinating for me, 0:07:42.880 --> 0:07:46.040 is just thinking about what physics can do. You know, 0:07:46.120 --> 0:07:48.440 you throw a whole bunch of stuff out into space 0:07:48.480 --> 0:07:51.240 and it forms stars and it forms planets, But not 0:07:51.400 --> 0:07:54.600 just that right, it can also do these other incredible things. 0:07:54.720 --> 0:07:57.760 And it's all these fascinating little wrinkles, these little bits 0:07:57.800 --> 0:08:01.000 of bling that really show us what gravity is capable 0:08:01.080 --> 0:08:04.600 of and the interplay between gravity and all the other forces. So, 0:08:04.640 --> 0:08:07.320 as we'll see on today's episode, these rings will teach 0:08:07.400 --> 0:08:09.840 us a lot about the nature of the Solar System 0:08:09.960 --> 0:08:12.880 and the universe that we live in. And so on 0:08:12.960 --> 0:08:21.600 today's episode we'll be tackling exactly that question. How do 0:08:21.760 --> 0:08:24.640 planets get rings? Okay, I'm gonna stop you right there, 0:08:24.680 --> 0:08:28.160 because I think I have the answer. It is aliens, 0:08:28.520 --> 0:08:33.920 giant aliens doing ring toss with our planets, or maybe 0:08:33.920 --> 0:08:37.120 it's hula hoops from a leftover enormous alien birthday party. 0:08:37.440 --> 0:08:40.160 We're basically their garbage bin. But it's an interesting question 0:08:40.280 --> 0:08:43.160 not just why are there rings, but how do planets 0:08:43.200 --> 0:08:45.800 get rings? Where do they come from? Why do some 0:08:45.840 --> 0:08:48.480 planets have rings and others don't. Why do some planets 0:08:48.480 --> 0:08:51.160 have more moons and fewer rings. What is the connection 0:08:51.200 --> 0:08:55.600 between rings and moons? Can moons have rings? Can rings 0:08:55.640 --> 0:08:58.880 exist on planets in other Solar systems? Is our Solar 0:08:58.880 --> 0:09:02.840 System weird for having this incredible planet with these huge rings, 0:09:03.320 --> 0:09:06.320 or are we weird for not having rings around every 0:09:06.400 --> 0:09:08.719 single planet? These are the kinds of questions we can 0:09:08.720 --> 0:09:11.400 now ask about our solar system because we have looked 0:09:11.400 --> 0:09:14.960 out through our telescopes into even other solar systems around 0:09:15.040 --> 0:09:17.560 other stars to try to get an answer to the 0:09:17.640 --> 0:09:21.360 question of is our solar system strange or is our 0:09:21.360 --> 0:09:25.680 solar system totally vanilla and typical. I find that an 0:09:25.679 --> 0:09:29.160 interesting way to describe if our solar system is similar 0:09:29.160 --> 0:09:33.079 to other solar systems, which is boring and vanilla. Well, 0:09:33.120 --> 0:09:35.839 it's a deep question, right, like are we typical? Are 0:09:35.880 --> 0:09:38.920 we boring? If alien scientists are studying the whole galaxy, 0:09:38.960 --> 0:09:41.480 would they find us an interesting case study or would 0:09:41.480 --> 0:09:43.920 they be like, oh, yeah, another one, just like all 0:09:43.960 --> 0:09:47.800 the other sixty five million systems that I've already studied. Right, 0:09:47.880 --> 0:09:50.199 we'd like to think that we are special in some sense. 0:09:50.240 --> 0:09:52.040 We'd like to imagine that we are at the center 0:09:52.080 --> 0:09:54.240 of the universe. We are unusual, we are sparkling, we 0:09:54.240 --> 0:09:56.640 are exceptional. On the other hand, I'd like to believe 0:09:56.679 --> 0:09:59.120 that we are vanilla, that we are boring, because that 0:09:59.160 --> 0:10:01.600 means it's probably more of us, right, That means it's 0:10:01.600 --> 0:10:04.240 probably life everywhere. One of my favorite things about this 0:10:04.320 --> 0:10:06.800 kind of question, is our solar system typical or not? 0:10:07.000 --> 0:10:09.960 Is that the answer is fascinating either way. Either we're 0:10:09.960 --> 0:10:12.440 incredibly unusual and then we get to ask why, or 0:10:12.480 --> 0:10:15.480 we're not, in which case we got lots of neighbors. Yeah, 0:10:15.679 --> 0:10:19.240 so you would favor us being basic solar system with 0:10:19.320 --> 0:10:22.480 our ugg boots and our Saturn's rings. That is kind 0:10:22.480 --> 0:10:25.880 of an interesting personality quick personality tests, like would you 0:10:25.960 --> 0:10:30.480 prefer our solar system to be unique and special in 0:10:30.640 --> 0:10:33.600 us to be the only planet with life or would 0:10:33.600 --> 0:10:37.079 you prefer us to be run of the mill lots 0:10:37.080 --> 0:10:39.840 of solar systems like ours out there and not feel 0:10:39.880 --> 0:10:42.960 so alone. I agree with you. I hope we're basic 0:10:43.120 --> 0:10:46.800 so that we've got some friends out there. Exactly, We 0:10:46.800 --> 0:10:49.560 can't answer that question directly today because our telescopes are 0:10:49.559 --> 0:10:53.080 not powerful enough to look through the atmospheres of exo planets. 0:10:53.080 --> 0:10:55.200 But we can look in our own backyard and try 0:10:55.240 --> 0:10:58.200 to understand how our solar system formed and if there's 0:10:58.200 --> 0:11:00.960 anything in it that we cannot explained. And it's an 0:11:01.000 --> 0:11:04.640 incredible piece of science to look around you and understand 0:11:04.679 --> 0:11:07.520 how we came together to build a model for the 0:11:07.559 --> 0:11:10.960 processes that could have formed such incredible structures, and to 0:11:11.000 --> 0:11:13.200 think about how long they might have taken. You know, 0:11:13.240 --> 0:11:15.839 we've done something similar here on Earth by looking under 0:11:15.840 --> 0:11:18.720 our feet and asking questions like do we understand how 0:11:18.800 --> 0:11:21.720 the Earth formed? And how the mountains have formed? And 0:11:21.760 --> 0:11:24.200 all the ridges that we see in the layers of rock, 0:11:24.360 --> 0:11:26.560 and those things are clues, the clues that led us 0:11:26.559 --> 0:11:30.800 to understand something really shocking, that the Earth is billions 0:11:30.800 --> 0:11:33.560 of years old, not thousands of years old. Right. We 0:11:33.640 --> 0:11:37.240 have the evidence all around us to reveal the story 0:11:37.480 --> 0:11:39.920 of the formation of the Solar System, but not just 0:11:40.040 --> 0:11:42.960 here on Earth, out there in space, and one of 0:11:42.960 --> 0:11:45.360 the funnest bits is to look at the rings around 0:11:45.360 --> 0:11:48.120 those planets. So that's what we're focusing on today. And 0:11:48.160 --> 0:11:51.319 I was curious whether people understood rings, whether rings were 0:11:51.320 --> 0:11:54.040 still a big source of mystery, or people thought they 0:11:54.040 --> 0:11:57.040 pretty much understood where they came from. So I went 0:11:57.040 --> 0:12:00.199 out there to our cadre of Internet volunteers, who are 0:12:00.240 --> 0:12:03.040 my random questions without a chance to prepare, which gives 0:12:03.080 --> 0:12:05.240 us a sense for what people know, what they think about, 0:12:05.240 --> 0:12:07.440 and what they want to hear about. If you'd like 0:12:07.520 --> 0:12:10.520 to participate for future episodes. Please don't be shy, just 0:12:10.640 --> 0:12:14.120 write to me two questions at Daniel and Jorge dot com. 0:12:14.160 --> 0:12:16.400 Before you hear these answers, think to yourself, do you 0:12:16.520 --> 0:12:20.000 have a good idea of where rings come from on planets? 0:12:20.440 --> 0:12:23.240 Here's what our listeners had to say, UM, and I'm 0:12:23.240 --> 0:12:26.559 pretty sure that I learned about this that UM like 0:12:26.640 --> 0:12:33.480 it's asteroids colliding near the planet itself and the remnants 0:12:33.559 --> 0:12:37.520 of those asteroids going into orbit and creating a sort 0:12:37.520 --> 0:12:41.160 of disc. I think the two classical ways are by 0:12:41.200 --> 0:12:44.520 planets capturing space debris um that's just floating through the 0:12:44.520 --> 0:12:48.320 Solar System, or by recapturing debris caused by an impact. 0:12:48.720 --> 0:12:52.480 But I've also heard of a moon orbiting Saturn. I 0:12:52.480 --> 0:12:55.320 believe that has a geyser and when the guys are 0:12:55.480 --> 0:12:59.400 spits out water um it forms into ice crystals, and 0:12:59.440 --> 0:13:02.880 then that joins the rings of Saturn. So maybe that's 0:13:02.880 --> 0:13:09.559 another option. Well, the rings are kind of like small satellites, 0:13:09.600 --> 0:13:12.040 I would say, like small moons, Like we have the 0:13:12.080 --> 0:13:15.960 most most really tiny moons that get around the planet. 0:13:16.440 --> 0:13:21.959 Each planet has its own way of doing the rings. Well, 0:13:22.000 --> 0:13:24.360 I wanted to say that planets can get rings if 0:13:24.400 --> 0:13:27.640 they collide with big rocky bodies, but I don't know 0:13:27.679 --> 0:13:31.160 how that would work with like gas giants and how 0:13:31.200 --> 0:13:33.560 they got their rings. So I'm going to guess that 0:13:33.640 --> 0:13:37.280 it's just stuff that is left over um from when 0:13:37.280 --> 0:13:39.920 the planet was formed, and it was just stuff that 0:13:39.960 --> 0:13:41.720 was so far away when it was being formed that 0:13:41.720 --> 0:13:43.599 it didn't become part of the planet, but it was 0:13:43.600 --> 0:13:45.720 still close enough to be influenced by the gravity of it. 0:13:45.840 --> 0:13:50.880 I'm almost certain it's got to do with the acreation 0:13:51.960 --> 0:13:57.680 process of when a planets formed and the attraction of 0:13:57.760 --> 0:14:02.840 the stuff towards the planet. Apart from that, I'm not 0:14:02.880 --> 0:14:07.080 really sure actually, because I think planets form when like 0:14:07.120 --> 0:14:11.200 a heavy metal gets caught in orbit around the star, 0:14:11.440 --> 0:14:14.160 so I think something similar happens around the planet. Debris 0:14:14.559 --> 0:14:18.800 and maybe rocks or particles of ice or something um 0:14:19.040 --> 0:14:22.720 gather around a planet in much the same way that 0:14:22.760 --> 0:14:28.360 planets gather around stars. Does all seem like really intelligent answers, 0:14:28.480 --> 0:14:31.400 but I still kind of like my giant alien ring 0:14:31.480 --> 0:14:35.280 toss theory. We'll put it on the list as the 0:14:35.400 --> 0:14:37.520 dark horse theory that might storm out at the end 0:14:37.560 --> 0:14:39.960 if we can't explain it with any of the other theories. 0:14:40.200 --> 0:14:43.000 So it seems like there are so many options for 0:14:43.120 --> 0:14:46.120 what these rings could be made of. How on Earth 0:14:46.160 --> 0:14:48.520 are we, or I should say, how in our Solar 0:14:48.560 --> 0:14:50.680 system are we going to be able to figure out 0:14:50.800 --> 0:14:53.440 what exactly they're made of? If there are so many 0:14:53.560 --> 0:14:56.600 different theories, so many different options for what they could 0:14:56.640 --> 0:14:58.840 be made of. Yeah, it's a great question. I listen 0:14:58.880 --> 0:15:01.120 to these answers and seems to me like they form 0:15:01.200 --> 0:15:05.080 in roughly two categories. There are some folks that say 0:15:05.120 --> 0:15:08.040 that it's basically debris from other stuff that broke up, 0:15:08.160 --> 0:15:11.360 like maybe you had comments or moons that smashed new 0:15:11.360 --> 0:15:14.160 each other and basically just made a big mess, you know. 0:15:14.480 --> 0:15:16.320 But then you have to wonder, like why don't those 0:15:16.360 --> 0:15:19.240 things gather together to make a new moon or to 0:15:19.280 --> 0:15:22.040 make a new comment or something. And the other category 0:15:22.240 --> 0:15:24.560 is like, maybe it's just left over from when the 0:15:24.600 --> 0:15:27.360 planet was formed, the same stuff that formed the planet, 0:15:27.360 --> 0:15:29.240 but some of it didn't get into the planet. So 0:15:29.280 --> 0:15:31.960 it seems like those are two different categories of ideas, 0:15:32.040 --> 0:15:34.520 And you ask a great question, how could we possibly 0:15:34.640 --> 0:15:37.520 ever figure this out? How could we know what the 0:15:37.640 --> 0:15:40.600 history is of the Solar System? And the answer is that. 0:15:40.640 --> 0:15:42.600 Of course, we can't just like watch a video of 0:15:42.640 --> 0:15:45.000 its formation, though we'd love to, but we can just 0:15:45.040 --> 0:15:47.560 look around us for clues. We can try to build 0:15:47.600 --> 0:15:50.640 up models for how rings might form, and then compare 0:15:50.720 --> 0:15:53.520 the details of those models to what we see. So 0:15:53.600 --> 0:15:55.600 the short answer is we need more money and more 0:15:55.680 --> 0:15:58.960 data to measure these rings, to look closely at them, 0:15:59.080 --> 0:16:01.200 to see what they are made out of, how much 0:16:01.280 --> 0:16:04.560 mass they have, what their distribution is. The more detail 0:16:04.600 --> 0:16:06.480 we can get about what they look like and what 0:16:06.560 --> 0:16:08.840 they're made out of, the better we can compare them 0:16:08.880 --> 0:16:12.200 to predictions from our theories about how they were formed. 0:16:12.400 --> 0:16:16.800 I mean, it sounds like a worthy use of funding. However, 0:16:16.960 --> 0:16:19.600 might I suggest an n f T of a farting 0:16:19.640 --> 0:16:22.720 panda instead? I'll put that on the proposed list and 0:16:22.760 --> 0:16:26.280 see where it goes. So when we're talking about rings, 0:16:26.320 --> 0:16:29.000 like what is it? Because you know my wedding ring 0:16:29.120 --> 0:16:34.359 is this solid band that sits around my finger. Hula 0:16:34.440 --> 0:16:38.520 hoop is this very thin tourists that you kind of 0:16:39.280 --> 0:16:43.040 use the motion of your hips to keep moving around 0:16:43.280 --> 0:16:46.800 with its momentum? So what are the rings that are 0:16:46.960 --> 0:16:50.600 around Saturn? Are they spinning around like a hula hoop 0:16:50.720 --> 0:16:52.800 or they just kind of sitting on it, like my 0:16:52.920 --> 0:16:55.360 wedding ring. It's a great question, and when it comes 0:16:55.360 --> 0:16:58.120 to astronomy, you always have to start with the definition, 0:16:58.240 --> 0:17:02.120 which immediately puts you in to a swamp, because nothing 0:17:02.200 --> 0:17:05.719 falls nicely into clean categories out there in space. You know, 0:17:05.760 --> 0:17:08.200 what's a planet, what's a minor planet, what's a centaur. 0:17:08.480 --> 0:17:11.760 A lot of these definitions come from history because we 0:17:11.760 --> 0:17:14.080 didn't really understand what was going on, and we just 0:17:14.080 --> 0:17:16.080 sort of named things randomly, and then we were sort 0:17:16.080 --> 0:17:19.200 of stuck with different categories and so often they could 0:17:19.200 --> 0:17:21.080 be a bit of a mess. Well, we're lucky in 0:17:21.160 --> 0:17:25.399 biology because species is super simple and never has that 0:17:25.520 --> 0:17:29.600 problem exactly. Nature doesn't confine itself to our categories. Was 0:17:29.720 --> 0:17:31.840 out there in the universe is not things that fall 0:17:31.880 --> 0:17:36.080 into crisply defined different boxes. It's a whole spectrum of stuff, right, 0:17:36.160 --> 0:17:38.719 And so we just got to put these arbitrary definitions 0:17:38.720 --> 0:17:40.600 out there so that we can talk to each other 0:17:40.680 --> 0:17:42.800 about it. So one of the most common definitions of 0:17:42.840 --> 0:17:46.320 a ring is a disc or ring composed of solid 0:17:46.400 --> 0:17:51.080 materials such as dust or moonlits. Moonlits. That sounds really cute, 0:17:51.320 --> 0:17:54.240 what's a moonlit moon is like a little moon, you know, 0:17:54.320 --> 0:17:59.560 like a little Moonito, the old baby moon, exactly a 0:17:59.560 --> 0:18:02.320 little my in your moon. Immediately understand, these rings are 0:18:02.359 --> 0:18:05.440 not actually a solid object. It's not like a hulu, right, 0:18:05.560 --> 0:18:08.760 or the rings around Saturn are not huge circles. They're 0:18:08.800 --> 0:18:12.119 actually a bunch of tiny little particles, a bunch of 0:18:12.200 --> 0:18:14.639 chunks that are moving in the same orbit. And so 0:18:14.720 --> 0:18:17.400 from far away it looks like a ring. Of course, 0:18:17.440 --> 0:18:19.919 it looks like a single hula hoop, for example, or 0:18:19.920 --> 0:18:22.080 a wedding ring. But if you zoomed in closely, you 0:18:22.160 --> 0:18:24.640 see it's actually a bunch of individual pieces that are 0:18:24.720 --> 0:18:27.679 not touching each other. So cartoons have lied to me. 0:18:27.800 --> 0:18:31.800 I cannot drive a race car or a skateboard around 0:18:32.000 --> 0:18:34.600 the rings of Saturn. That's right. You can't do Mario 0:18:34.720 --> 0:18:37.040 Kart on the rings of Saturn and you would fall 0:18:37.160 --> 0:18:40.560 right through. It's very disappointing. Cartoons play it real fast 0:18:40.600 --> 0:18:44.919 and loose with physics I'm discovering. And so basically a 0:18:45.040 --> 0:18:47.679 ring is just like a disc of material in a 0:18:47.680 --> 0:18:49.800 single orbit, moving all around. And that makes it a 0:18:49.800 --> 0:18:52.960 little bit unusual because orbits are usually for one object 0:18:53.160 --> 0:18:55.040 you know, like the Moon orbits the Earth and there's 0:18:55.040 --> 0:18:57.600 nothing else in the Moon's orbit. It's not like there's 0:18:57.600 --> 0:19:00.560 something else on the other side, or the Earth disorbiting 0:19:00.600 --> 0:19:03.680 the Sun and there's nothing else in Earth's orbit, right, 0:19:03.720 --> 0:19:06.800 it clears its own path. So it's a bunch of 0:19:07.119 --> 0:19:11.879 individual things sharing a single orbit, kind of like a 0:19:11.960 --> 0:19:15.720 lazy river at a water park exactly so to like 0:19:15.760 --> 0:19:18.200 a lazy river. And once you define it that way, 0:19:18.240 --> 0:19:20.840 you can ask questions like, well, what counts as a ring? 0:19:21.000 --> 0:19:23.280 You know, does it have to be natural? For example, 0:19:23.440 --> 0:19:26.479 like Earth has a bunch of stuff out there in space, 0:19:26.560 --> 0:19:29.440 things we have launched out there, a bunch of satellites 0:19:29.600 --> 0:19:32.520 in the same orbit, you know, zooming all around. Does 0:19:32.560 --> 0:19:35.080 that count as a ring? Have we built our own 0:19:35.200 --> 0:19:37.920 ring system around the Earth because all of the junk 0:19:38.000 --> 0:19:40.399 that we put out there in space. Nobody talks about 0:19:40.440 --> 0:19:43.399 Earth's rings, but technically, you know, it seems like that 0:19:43.480 --> 0:19:47.159 might qualify. There's no like minimum mass requirement for the 0:19:47.280 --> 0:19:49.520 rings as far as I can tell, so we're one 0:19:49.560 --> 0:19:53.480 step closer to Halo am I right, high fibes everyone 0:19:53.560 --> 0:19:57.760 who plays computer games. Another requirement for rings usually is 0:19:57.760 --> 0:19:59.960 that they are pretty flat right, if you have just 0:20:00.119 --> 0:20:03.000 like a swarm of spherical swarm of objects, then your 0:20:03.000 --> 0:20:05.640 planet is just surrounded by junk. A ring is typically 0:20:05.680 --> 0:20:07.920 something which is flattened, right, it's more like a disc. 0:20:08.280 --> 0:20:11.359 And this already shows off what's going on with gravity. 0:20:11.640 --> 0:20:14.720 You know, gravity has pulled the planet together and it's spinning, 0:20:14.760 --> 0:20:17.399 and it's also pulled the ring together. And the reason 0:20:17.440 --> 0:20:20.000 that rings form in disks is the same reason that 0:20:20.040 --> 0:20:22.919 the Solar system is a disc. Right. That most of 0:20:22.920 --> 0:20:25.320 the stuff is spinning in the same direction, along the 0:20:25.359 --> 0:20:29.159 same plane, and that's because of conservation of angular momentum. 0:20:29.520 --> 0:20:33.719 Stuff that spinning keeps spinning, and if gravity pulls it together, 0:20:33.760 --> 0:20:36.480 it keeps spinning. It's harder for gravity to pull together 0:20:36.760 --> 0:20:40.439 towards the spin axis than along the spin axis the 0:20:40.480 --> 0:20:44.000 same way. For example, that like Earth resists falling into 0:20:44.040 --> 0:20:47.520 the Sun because of its speed because of its angular momentum, right, 0:20:47.560 --> 0:20:50.640 But the Earth didn't resist falling into the Sun's plane. 0:20:50.920 --> 0:20:53.639 So gravity is free to compress things down into a 0:20:53.680 --> 0:20:56.880 flat disc. But angular momentum keeps things spinning and keep 0:20:56.920 --> 0:20:59.560 things from falling in That's what gives rings these sort 0:20:59.600 --> 0:21:02.640 of flat structure. So that's another typical thing we expect 0:21:02.720 --> 0:21:06.080 of rings that they're not spherical distributions of stuff. They're 0:21:06.080 --> 0:21:08.800 like these flat disks. Because that's sort of like if 0:21:08.840 --> 0:21:11.960 you pile a bunch of peas on a plate and 0:21:11.960 --> 0:21:14.119 then spin the plate, all the p's are going to 0:21:14.280 --> 0:21:17.080 scatter outwards and get everywhere, but in sort of a 0:21:17.119 --> 0:21:20.919 flat circle. I've never done that experiment, but yes, in 0:21:20.960 --> 0:21:24.400 my mind that that's exactly what you don't do that. 0:21:24.720 --> 0:21:27.760