WEBVTT - Should We Mine the Asteroid Belt? (feat. Phil Plait) 0:00:01.400 --> 0:00:05.000 Hey, Welcome to Science Stuff, a production of iHeartRadio. Hoor 0:00:05.040 --> 0:00:09.639 Hey cham and today we're talking about asteroids. What exactly 0:00:09.680 --> 0:00:12.200 are they? Should we go out there and mind them 0:00:12.440 --> 0:00:14.880 or is one of them going to crash into Earth 0:00:15.080 --> 0:00:17.880 and wipe us out. We're going to be talking to 0:00:17.880 --> 0:00:20.800 one of the most famous astronomers on the planet about this, 0:00:21.079 --> 0:00:23.799 Who's going to step us through the nuances of how 0:00:24.000 --> 0:00:27.120 asteroids form, what it would be like to step on one, 0:00:27.520 --> 0:00:31.600 and what the most valuable resource in them actually is. 0:00:32.159 --> 0:00:35.839 So get your asteroids and gear as we tackle the 0:00:36.040 --> 0:00:45.960 meaty or topic of space rocks enjoying. Hey everyone. I 0:00:45.960 --> 0:00:49.040 don't know about you, but I like planet Earth and 0:00:49.440 --> 0:00:51.839 I'm not in a big hurry to leave it. But 0:00:51.880 --> 0:00:54.400 it does seem that at the rate we're going, we 0:00:54.640 --> 0:00:57.480 might run out of things here, which is why billionaires 0:00:57.520 --> 0:01:01.400 and space enthusiasts have proposed maybe goin shopping out there 0:01:01.600 --> 0:01:05.240 in the asteroid belt. I also like our planet enough 0:01:05.280 --> 0:01:07.440 that I don't want to see anything happen to it, 0:01:07.880 --> 0:01:12.080 like getting hit by an asteroid. So basically I had 0:01:12.120 --> 0:01:15.520 a lot of asteroid questions to answer them, I thought 0:01:15.520 --> 0:01:17.280 I'd reach out to one of the most well known 0:01:17.280 --> 0:01:21.760 astronomers on the planet. Doctor Phil Plait Doctor Plate, is 0:01:21.760 --> 0:01:24.800 the creator of the website Bad Astronomy, as well as 0:01:24.840 --> 0:01:29.120 the author of several books, including Death from Disguise, a 0:01:29.200 --> 0:01:31.880 fun survey of all the ways things from space can 0:01:32.360 --> 0:01:34.959 kill us, including asteroids. 0:01:37.640 --> 0:01:39.000 He also wrote Under. 0:01:38.800 --> 0:01:41.720 Alien Skies about what it would be like to visit 0:01:41.800 --> 0:01:45.440 other parts of the universe, like an asteroid. So I 0:01:45.520 --> 0:01:49.520 had three questions for doctor Plate. Number one, what exactly 0:01:49.840 --> 0:01:52.640 is an asteroid? It turns out there's a lot of 0:01:52.680 --> 0:01:56.400 people get wrong about that. Number two, is an asteroid 0:01:56.480 --> 0:01:58.680 going to hit the Earth and why it was out? 0:01:59.160 --> 0:02:03.480 And three should we mine the asteroid belt? It turns 0:02:03.520 --> 0:02:06.480 out there's more than just rocks and metals out there. 0:02:07.040 --> 0:02:11.360 We'll start with the first question, what exactly is an asteroid? 0:02:11.760 --> 0:02:17.200 Here's my conversation with doctor Phil Plate. Well, thank you 0:02:17.240 --> 0:02:18.400 doctor Plate for joining us. 0:02:18.800 --> 0:02:21.080 Oh my pleasure. It's nice to see you and hear you. 0:02:21.280 --> 0:02:23.120 I suppose hear you. Well. 0:02:23.160 --> 0:02:25.120 I think we're both not enough that everyone knows what 0:02:25.160 --> 0:02:27.120 we look like, or can know what we look like 0:02:27.240 --> 0:02:28.080 with a simple search. 0:02:28.280 --> 0:02:30.959 I'm not too hard to picture, you know, little aged, balding, 0:02:30.960 --> 0:02:31.720 bearded white guy. 0:02:31.800 --> 0:02:32.640 Yeah, you've seen me. 0:02:33.760 --> 0:02:35.919 Well, you famously read a book called Death from the 0:02:35.960 --> 0:02:39.160 Skies in which you talk about, among other things, the 0:02:39.200 --> 0:02:41.799 possibility of an asteroid hitting the Earth. 0:02:41.880 --> 0:02:43.120 We'll get into that, but. 0:02:43.120 --> 0:02:46.160 I guess maybe for people who are not familiar, what 0:02:46.240 --> 0:02:48.079 is technically an asteroid? 0:02:48.320 --> 0:02:50.400 Yeah, you know, this is one of those questions where 0:02:50.400 --> 0:02:53.240 it's like this is really easy to ask and super 0:02:53.280 --> 0:02:55.880 hard to answer. When you think of an asteroid, you 0:02:55.919 --> 0:02:58.960 probably think of a you know, big rock in space 0:02:59.040 --> 0:03:02.560 that's floating around orbiting the Sun. But it gets complicated. 0:03:02.880 --> 0:03:04.079 That's not the definition of it. 0:03:04.480 --> 0:03:08.200 Well, there's no real definition. There's not really a size 0:03:08.320 --> 0:03:11.120 on these things. The biggest ones are a few hundred 0:03:11.200 --> 0:03:14.239 kilometers across or miles if you're an American, but there's 0:03:14.280 --> 0:03:17.720 no sort of lower size limit to them. You could 0:03:17.760 --> 0:03:20.520 think of something a meter across, the size of a 0:03:20.600 --> 0:03:24.640 chair as an asteroid, and that's not wrong. But if 0:03:24.639 --> 0:03:27.120 it's the size of a grain of sand, I don't 0:03:27.160 --> 0:03:30.000 know what you would call that necessarily a meteoroid, but 0:03:30.040 --> 0:03:31.919 it's still kind of an asteroid. So that's what these 0:03:31.960 --> 0:03:34.720 things are. You know. I wouldn't call something the size 0:03:34.720 --> 0:03:37.080 of a grape an asteroid, but. 0:03:37.120 --> 0:03:39.240 It kind of is kind of that's what happens. 0:03:39.280 --> 0:03:40.240 You don't have a definition. 0:03:40.600 --> 0:03:42.960 It's a like a vibe. You go in by vibes. 0:03:43.840 --> 0:03:48.000 For the definition of asteroids, Yeah, yes, there is no 0:03:48.240 --> 0:03:52.080 clear definition of what an asteroid is. I mean, it 0:03:52.160 --> 0:03:56.480 basically means space rock, but not always. If the rock 0:03:56.560 --> 0:03:59.680 is mostly made of ice, then astronomers call it a 0:04:00.680 --> 0:04:02.960 or If the rocks are small enough, they call it 0:04:03.200 --> 0:04:05.480 space dust. And if the rock is on t way 0:04:05.520 --> 0:04:09.000 to Earth, they might call it a meteority. Now, the 0:04:09.040 --> 0:04:12.600 size of asteroids vary according to what scientists call an 0:04:12.720 --> 0:04:16.640 inverse law, meaning the bigger an asteroid is. 0:04:16.720 --> 0:04:18.040 The rarer it is. 0:04:18.440 --> 0:04:23.400 For example, really really big asteroids about one thousand kilometers wide. 0:04:23.600 --> 0:04:28.720 There's one it's called series asteroids about one hundred or 0:04:28.760 --> 0:04:32.080 more kilometers wide. There are about two hundred of them. 0:04:32.480 --> 0:04:35.719 But smaller asteroids there are a lot. 0:04:37.320 --> 0:04:38.960 As they get bigger, there are a fewer of them, 0:04:38.960 --> 0:04:41.080 which is just kind of how nature operates. And it 0:04:41.080 --> 0:04:43.880 turns out bigger than about one hundred meters you know, 0:04:44.080 --> 0:04:47.960 football field sized. There are probably a billion of them 0:04:48.120 --> 0:04:51.640 orbiting between Mars and Jupiter, which is a lot. But 0:04:52.200 --> 0:04:54.160 if you say how many are bigger than a meter across. 0:04:54.320 --> 0:04:56.240 I heave't no, it's hundreds of billions, trillions. I don't 0:04:56.240 --> 0:04:56.600 even know. 0:04:58.080 --> 0:05:01.200 There are a lot of asteroids out there. But before 0:05:01.200 --> 0:05:03.480 you get the idea that space is full of rocks 0:05:03.520 --> 0:05:06.279 flying all over the place, kind of like that asteroid 0:05:06.360 --> 0:05:09.760 field and solo flu, the Millennium falcon through and the 0:05:09.760 --> 0:05:14.719 Empire strikes back, you should know two things. First, space 0:05:15.160 --> 0:05:16.560 is big. 0:05:17.960 --> 0:05:19.160 And the thing is there are so many of them, 0:05:19.160 --> 0:05:21.680 and you think, my heavens Empire strikes back. You know, 0:05:21.680 --> 0:05:23.599 if I can quote what is now an. 0:05:23.440 --> 0:05:26.520 Ancient movie, let's not get into how the artful. 0:05:27.000 --> 0:05:29.520 Yeah, you have a space ship and it's going through 0:05:29.520 --> 0:05:31.599 an asteroid belt and they're asteroids everywhere, and it's like, no, 0:05:31.640 --> 0:05:34.240 it's not like that. In fact, when you look at 0:05:34.320 --> 0:05:37.000 how much space is between Mars and Jupiter, and it's 0:05:37.160 --> 0:05:40.600 you know, it's a several hundred million kilometers between them. 0:05:41.040 --> 0:05:43.520 And a friend of mine who studies asteroids actually told 0:05:43.520 --> 0:05:45.400 me this that if you take all of the one 0:05:45.480 --> 0:05:49.279 hundred meter sized asteroids a hundred meters, you know, that's decent, 0:05:49.800 --> 0:05:52.320 and you stand on one in the asteroid belt. If 0:05:52.320 --> 0:05:54.440 you were to spread them out evenly, you would not 0:05:54.520 --> 0:05:58.200 be able to see another asteroid with your naked eye. Whoa, 0:05:59.279 --> 0:06:01.400 they would all be so far away they'd be too 0:06:01.400 --> 0:06:03.599 faint to see. They're actually really far apart. 0:06:04.320 --> 0:06:07.240 Wow, it's pretty rare in the Solar System. It seems 0:06:07.360 --> 0:06:08.719 to run into one an asteroid. 0:06:08.880 --> 0:06:11.599 Yeah, and it just depends on what you mean, right, Yeah, 0:06:11.640 --> 0:06:14.960 there's zillions of them, so they're not rare, but they're 0:06:15.000 --> 0:06:17.559 so few and far between because of the just vast 0:06:17.600 --> 0:06:21.280 amount of space out there that you could go and 0:06:21.400 --> 0:06:24.200 travel to Jupiter and back thousands of times and never 0:06:24.240 --> 0:06:25.640 get even close enough to one to see. 0:06:26.720 --> 0:06:29.840 So there are hundreds of millions of asteroids out there, 0:06:30.080 --> 0:06:33.559 but space is so big you would rarely run into one, 0:06:33.880 --> 0:06:36.600 even in the area of the Solar System called the 0:06:36.640 --> 0:06:39.880 asteroid Belt. And the other thing is that even though 0:06:39.920 --> 0:06:43.400 there are huge asteroids out there and hundreds of millions 0:06:43.480 --> 0:06:47.559 of little asteroids, they actually don't add up too very much. 0:06:49.080 --> 0:06:51.480 Do you have a sense of how much asteroid mass 0:06:51.600 --> 0:06:52.159 is out there? 0:06:52.440 --> 0:06:55.600 The weird thing is if you add them all up together, 0:06:56.000 --> 0:06:58.120 you don't get a very big object. Even though there 0:06:58.120 --> 0:07:01.240 could be a trillion little ones. The biggest ones really 0:07:01.480 --> 0:07:04.000 eat up most of the space, and so you wind 0:07:04.120 --> 0:07:06.440 up getting something that's actually quite small. It's just a 0:07:06.480 --> 0:07:10.440 couple of thousand kilometers across what's smaller maybe than Earth's moon, 0:07:10.560 --> 0:07:13.000 or maybe the size of Earth's moon, something like that. 0:07:13.200 --> 0:07:15.000 Although there are lots of them, they don't add up 0:07:15.000 --> 0:07:15.560 too much. 0:07:15.880 --> 0:07:18.400 Interesting, and you're talking about all the asteroids in the 0:07:18.480 --> 0:07:19.800 asteroid belt. 0:07:19.920 --> 0:07:23.080 Yeah, and I could include the entire Solar System, although 0:07:23.320 --> 0:07:25.560 it gets more complicated if you go out past Neptune. 0:07:25.560 --> 0:07:27.760 There are these bodies out there that we call the 0:07:27.800 --> 0:07:31.320 Kuiper Belt and the ort Cloud, which is comets. There 0:07:31.320 --> 0:07:34.520 are objects that orbit the Sun beyond Neptune, and those 0:07:34.520 --> 0:07:36.880 get pretty big. I mean, you're talking about Pluto. There 0:07:36.880 --> 0:07:39.960 are probably a handful of objects roughly the size of Pluto, 0:07:40.320 --> 0:07:43.360 and so these are actually decent size. Those would add up, oh, 0:07:43.400 --> 0:07:45.640 I don't know, twice the volume, ten times the volume 0:07:45.640 --> 0:07:48.320 of the Moon. So you're still not talking about a planet. 0:07:48.360 --> 0:07:52.520 I don't think. You know, it's certainly not Jupiter or 0:07:52.560 --> 0:07:54.160 that sort of thing. You've got a lot of these things, 0:07:54.200 --> 0:07:55.119 but they're small. 0:07:55.360 --> 0:07:57.840 Oh, that's fascinating. It doesn't seem like a lot. Yeah, 0:07:57.880 --> 0:08:02.679 it's amazing, Okay, The last cool thing about asteroids before 0:08:02.680 --> 0:08:04.680 we get to the questions of whether we should mind 0:08:04.720 --> 0:08:06.320 them or whether one of them is going to hit 0:08:06.360 --> 0:08:09.360 the Earth and kill us all, is that asteroids are 0:08:09.400 --> 0:08:12.520 not as solid as some people would think. According to 0:08:12.600 --> 0:08:15.120 doctor Plate, they can be kind of crumply. 0:08:16.640 --> 0:08:19.440 Some of them are. And this gets weird. Oh, this 0:08:19.480 --> 0:08:22.240 gets so weird. This is a relatively new concept. Are 0:08:22.280 --> 0:08:26.160 there rubbel piles? So instead of being a solid object 0:08:26.200 --> 0:08:28.720 like a rock in your backyard, a chunk of rock, 0:08:29.640 --> 0:08:34.079 there are actually thousands or millions or billions of smaller rocks, 0:08:34.640 --> 0:08:37.080 tiny ones up to maybe the size of boulders, that 0:08:37.160 --> 0:08:39.760 are all held together by their very weak gravity. What 0:08:40.360 --> 0:08:42.680 and so it's like having a bag of rocks, but 0:08:42.760 --> 0:08:45.520 you remove the bag and what you're lift with is 0:08:45.559 --> 0:08:47.920 just the gravity holding them together. And a lot of 0:08:47.960 --> 0:08:51.400 the smaller ones, and we think the majority of smaller 0:08:51.480 --> 0:08:53.920 asteroids are these rubble piles. So that's what they look like. 0:08:53.960 --> 0:08:56.160 When you see pictures of them, you're like, yeah, that's 0:08:56.240 --> 0:08:58.880 actually not a solid surface, that is just a bunch 0:08:58.960 --> 0:08:59.400 of rocks. 0:09:00.760 --> 0:09:02.360 Well, what was happened? If you went there and he 0:09:02.440 --> 0:09:04.599 stood on this, would you think. 0:09:04.480 --> 0:09:07.559 Well, that's a good question. The thing is, these rocks, 0:09:07.640 --> 0:09:11.160 as we found, are very friable, which means they are 0:09:11.240 --> 0:09:13.800 incredibly fragile, and if you were to hold one in 0:09:13.840 --> 0:09:17.040 your hand, you could just crush it. There's very little 0:09:17.080 --> 0:09:20.240 structural strength to these things, and we found that out 0:09:20.320 --> 0:09:22.840 when a spacecraft, and I want to say it was 0:09:22.920 --> 0:09:25.760 Osiris Rex, went up to the asteroid and hit it 0:09:25.800 --> 0:09:28.880 at a very slow speed to collect material. It had 0:09:29.400 --> 0:09:32.080 a sample collector, and the idea was that it would 0:09:32.080 --> 0:09:34.480 go up to the asteroid and it would blow rocks 0:09:34.480 --> 0:09:37.440 off and stuff and collect them into this collector. It 0:09:37.559 --> 0:09:42.160 hit the asteroid and actually kept going. It penetrated down 0:09:42.640 --> 0:09:45.800 about a half a meter into the asteroid itself, which 0:09:46.120 --> 0:09:48.800 was a surprise, and they had to like break and 0:09:48.920 --> 0:09:50.880 reverse thrust and get it back out of there. They 0:09:50.880 --> 0:09:52.640 thought it might penetrate a little bit, but I think 0:09:52.640 --> 0:09:54.880 they were surprised by how much. So, Yeah, if you 0:09:54.960 --> 0:09:57.000 were to visit one of these things in a spaceship 0:09:57.480 --> 0:09:59.760 and say I'm going to jump from my ship and 0:10:00.120 --> 0:10:03.040 land on this asteroid feet first, you might just sink 0:10:03.440 --> 0:10:08.280 right into it, which would be embarrassing and potentially life threatening, 0:10:09.480 --> 0:10:11.199 So don't do it. 0:10:11.280 --> 0:10:13.280 So what you say, at least a lot of the 0:10:13.480 --> 0:10:16.400 what we think of as large ash asteroids out there 0:10:16.440 --> 0:10:18.679 are actually just kind of like crumbly cookies. 0:10:19.200 --> 0:10:23.360 Crumbly cookies, that's pretty good. It is true that a 0:10:23.360 --> 0:10:24.920 lot of the ones that get in near Earth that 0:10:24.960 --> 0:10:28.600 we have visited are like this. Some comets are like this. 0:10:29.000 --> 0:10:32.040 I think this is not at all how I was 0:10:32.120 --> 0:10:33.640 raised learning about asteroids. 0:10:33.720 --> 0:10:34.000 Yeah. 0:10:34.160 --> 0:10:37.440 Yeah, I feel like we've concluded that Star Wars has 0:10:37.760 --> 0:10:44.280 misled us for years unbelievably. Yes, so it's hard to 0:10:44.360 --> 0:10:47.800 run into an asteroid a large asteroid, and a lot 0:10:47.840 --> 0:10:50.280 of them are not sort of big solid rocks, the 0:10:50.480 --> 0:10:52.000 sort of crumbly cookies. 0:10:52.040 --> 0:10:54.800 Basically, the force is not worth it. 0:10:56.480 --> 0:10:59.679 Okay, so those are the basics of asteroids. Now I'll 0:10:59.679 --> 0:11:04.040 get to the big questions. Should we mind the asteroid belt? 0:11:04.720 --> 0:11:08.480 And is an asteroid gonna hit the Earth? It turns 0:11:08.480 --> 0:11:11.320 out that the answer to both of these questions, according 0:11:11.360 --> 0:11:17.080 to doctor Plate, is yes. When we come back, we're 0:11:17.080 --> 0:11:21.040 gonna venture out even further to examine how asteroids can 0:11:21.120 --> 0:11:24.040 kill us and how they can also save us. 0:11:24.559 --> 0:11:26.200 To stay with us, we'll. 0:11:25.960 --> 0:11:46.240 Be right back. Hey, we'll come back. We're talking about asteroids. 0:11:46.520 --> 0:11:49.040 Whether we should mind them and if one of them 0:11:49.120 --> 0:11:51.120 is going to hit the Earth and wipe us out. 0:11:52.600 --> 0:11:55.560 So far, we've talked about what an asteroid actually is 0:11:56.080 --> 0:11:58.960 and how many are out there now. Most of what 0:11:59.000 --> 0:12:02.480 we call asteroids, meaning rocks floating in space, come from 0:12:02.520 --> 0:12:05.720 the asteroid belt, which is the big ring between the 0:12:05.840 --> 0:12:08.880 orbits of Mars and Jupiter. So if you were to 0:12:08.920 --> 0:12:11.840 fly from Earth towards the edge of the Solar System, 0:12:12.000 --> 0:12:15.040 you'd hit the orbit of Mars, then the asteroid belt, 0:12:15.320 --> 0:12:19.640 then the orbit of Jupiter, Saturn, Urinus, and Neptune. And 0:12:19.800 --> 0:12:23.920 the reason the asteroid belt is there is pretty cool. Basically, 0:12:24.120 --> 0:12:25.920 you can blame Jupiter. 0:12:27.920 --> 0:12:31.880 So the early Solar System was the Sun, the young Sun, 0:12:31.960 --> 0:12:35.120 surrounded by this disk of material that's gas and dust 0:12:35.200 --> 0:12:38.440 and rock and stuff like that. These things started to accumulate. 0:12:38.679 --> 0:12:40.880 Grains would bump into each other and turn into pebbles. 0:12:40.880 --> 0:12:43.800 Pebbles bump into each other, turn into boulders, and eventually 0:12:43.840 --> 0:12:46.040 you would grow to get something like a planet. That's 0:12:46.040 --> 0:12:50.040 how our planets formed. But between Mars and Jupiter, Jupiter's 0:12:50.080 --> 0:12:52.679 gravity is very strong, and so any sort of object 0:12:52.720 --> 0:12:54.880 that would try to get big enough to form a planet. 0:12:55.240 --> 0:12:57.760 Jupiter's gravity would kind of swing it around, make it 0:12:57.800 --> 0:13:00.960 move faster, slam into other stuff in the asteroid belt, 0:13:01.000 --> 0:13:01.559 shatter it. 0:13:02.400 --> 0:13:06.080 So basically, the asteroid belt is the graveyard of the 0:13:06.160 --> 0:13:10.680 chaos caused by the huge gravity of Jupiter. Any planets 0:13:10.679 --> 0:13:13.199 that try to form there would get dragged by Jupiter 0:13:13.400 --> 0:13:15.679 and slammed into other rocks. 0:13:16.000 --> 0:13:18.400 And as we mentioned before, there are a lot. 0:13:18.240 --> 0:13:21.920 Of rocks in the asteroid belt, and sometimes those rocks 0:13:21.920 --> 0:13:24.880 can bump into each other and get nudge to fall 0:13:25.040 --> 0:13:28.600 in our direction, which raises the possibility that one of 0:13:28.640 --> 0:13:32.120 them could hit us. It wouldn't be the first time. 0:13:32.679 --> 0:13:37.040 Sixty five million years ago, an asteroid called the Chicchulub impactor, 0:13:37.280 --> 0:13:40.520 which was about fourteen kilometers wide, hit the Earth and 0:13:40.640 --> 0:13:43.840 caused so much mayhem that it killed fifty percent of 0:13:43.880 --> 0:13:47.120 all species on Earth, including the dinosaurs. 0:13:48.440 --> 0:13:49.400 Could it happen again? 0:13:50.080 --> 0:13:54.720 That was the next question I asked, Doctor Blade, Doctor Plade, 0:13:54.760 --> 0:13:56.600 is an asteroid going to hit the Earth? What's the 0:13:56.720 --> 0:13:59.319 likelihood of that happening? One hundred percent? 0:14:00.000 --> 0:14:02.640 One hitting us right now as we're talking? What there 0:14:02.640 --> 0:14:05.040 are thousands of hitting us right now? Well, I said, 0:14:05.040 --> 0:14:07.240 there's no lower limit to the size of an asteroid. Right, 0:14:07.280 --> 0:14:09.800 So if you consider something like a grain of sand 0:14:10.000 --> 0:14:13.720 an asteroid, there are fifty to one hundred tons of 0:14:13.800 --> 0:14:17.520 material that hits Earth every day. What so, zillions of 0:14:17.520 --> 0:14:19.240 these things are hitting Earth all the time, and you 0:14:19.240 --> 0:14:22.200 see them burning up as meteors shooting stars. If you 0:14:22.240 --> 0:14:24.840 call those asteroids, then we're getting hit all the time. 0:14:25.040 --> 0:14:30.040 If you say, oh, let's say something that's a meter across, 0:14:30.120 --> 0:14:32.320 then we get hit by something that size once a month, 0:14:32.680 --> 0:14:36.600 as we're speaking. One fell over Europe a few days ago, 0:14:36.760 --> 0:14:39.320 and a couple of nights ago, one came over Ohio 0:14:39.360 --> 0:14:41.680 and Pennsylvania was seen by thousands of people. 0:14:41.760 --> 0:14:43.880 You heard about that, Yeah, I saw the needs. 0:14:44.000 --> 0:14:46.240 Yeah, it was really bright. Yeah, I've seen the videos. 0:14:46.280 --> 0:14:49.480 It's pretty cool. We get hit by those on timescales 0:14:49.480 --> 0:14:51.680 of a month or so, and the bigger they are, 0:14:51.720 --> 0:14:52.680 the more rare they are. 0:14:53.560 --> 0:14:55.680 What picker Plate is saying is that just like the 0:14:55.720 --> 0:14:59.080 sizes of asteroids out in space, follow an inverse law, 0:14:59.480 --> 0:15:02.040 so that the asteroids that happened to hit the Earth, 0:15:02.680 --> 0:15:05.520 small asteroids hit Earth all the time, but as they 0:15:05.520 --> 0:15:09.520 get bigger, they get rarer and rarer. One of the 0:15:09.560 --> 0:15:12.000 biggest ones to hit US in recent years with the 0:15:12.160 --> 0:15:16.080 Cheliabinsk meteor event, which you can find video of if 0:15:16.120 --> 0:15:17.600 you search for it online. 0:15:18.120 --> 0:15:31.920 Actually, so when you talk about something like the chel 0:15:31.960 --> 0:15:36.360 Yabinsk impact, which was in Russia in twenty thirteen, that 0:15:36.560 --> 0:15:38.800 was nineteen meters across, so you're talking to something the 0:15:38.880 --> 0:15:41.400 size of a house, big house. Those are much more rare. 0:15:41.440 --> 0:15:45.160 Those you're talking about every few decades or century. If 0:15:45.160 --> 0:15:47.880 one is fifty meters across and gets closer than that, 0:15:48.120 --> 0:15:50.760 it's not great. You don't want that, but it's not 0:15:50.920 --> 0:15:54.480 classified as potentially hazardous. It's still if it hits Earth, 0:15:54.520 --> 0:15:56.360 it'll blow up like a nuclear weapon. I mean, you're 0:15:56.360 --> 0:15:59.960 still talking about a megaton or more explosion. That's bad, 0:16:00.680 --> 0:16:02.440 but it's not a global catastrophe. 0:16:02.680 --> 0:16:05.600 Okay, but at around one hundred and footy meters that 0:16:05.640 --> 0:16:07.880 could be a global catastrophe, Yeah. 0:16:07.840 --> 0:16:09.880 I think regional. So you're talking about if one hit 0:16:09.920 --> 0:16:12.120 in the middle of the US, it would be catastrophic 0:16:12.160 --> 0:16:15.280 for US, but not necessarily for you know, India or 0:16:15.280 --> 0:16:18.840 something like that, although it's not great and certainly economically 0:16:18.920 --> 0:16:21.479 you know, if you hit a country that is economically 0:16:21.520 --> 0:16:22.880 critical to the rest of the world. 0:16:23.200 --> 0:16:23.840 That's bad. 0:16:23.920 --> 0:16:26.320 I mean, we saw what happened when like a terrorist 0:16:26.360 --> 0:16:28.720 attack can cripple the economy of a country and bring 0:16:28.720 --> 0:16:31.280 about a global recession. So you don't want these things 0:16:31.360 --> 0:16:35.480 hitting over New York City, Moscow, you know, anything like that. 0:16:35.480 --> 0:16:36.720 That would be very, very bad. 0:16:37.440 --> 0:16:39.640 So's if a one hundred footy meter asteroids hit is 0:16:39.880 --> 0:16:41.920 it would be about how many nuclear weapons? 0:16:42.080 --> 0:16:47.800 Oh golly, so something like two hundred megatons, so multiple 0:16:47.880 --> 0:16:52.560 times the largest nuclear weapon ever dropped. But it's not radioactive, 0:16:52.600 --> 0:16:56.680 so at least you know, yay, no fallout. Hooray. 0:16:57.000 --> 0:17:00.800 It's still bad, Okay, quick recap here. 0:17:00.960 --> 0:17:04.480 Earth is hit by asteroids all the time, but most 0:17:04.480 --> 0:17:07.280 of the time they're small and they end up burning 0:17:07.359 --> 0:17:09.920 up when they hit all that air in the atmosphere. 0:17:10.240 --> 0:17:13.440 That's what a shooting star is. When the asteroids start 0:17:13.480 --> 0:17:16.400 getting about fifty to one hundred and forty meters wide, 0:17:16.640 --> 0:17:19.440 that's when they can do a lot of damage. 0:17:19.560 --> 0:17:20.520 They could wipe by. 0:17:20.400 --> 0:17:23.520 The city and maybe cause a global crisis, but it 0:17:23.560 --> 0:17:27.520 wouldn't end the human race. And luckily that size of 0:17:27.560 --> 0:17:32.200 asteroid only hits Earth statistically every one hundred years or so. 0:17:32.280 --> 0:17:34.800 Now you might be wondering, what about the big ones, 0:17:35.040 --> 0:17:37.280 you know, like the one that took out the dinosaurs, 0:17:37.280 --> 0:17:39.640 that are like several kilometers wide. 0:17:40.000 --> 0:17:41.960 Those would be really bad. 0:17:42.520 --> 0:17:46.240 But actually scientists are not too worried about those because 0:17:46.400 --> 0:17:49.960 remember the inverse law of asteroids says, there aren't that 0:17:50.040 --> 0:17:51.359 many of them out there. 0:17:53.760 --> 0:17:56.320 We know there are no large asteroids big enough to 0:17:56.359 --> 0:18:00.600 be catastrophic globally, like an extinction level event. There's none 0:18:01.040 --> 0:18:03.400 that can get near us for at least the next century. 0:18:03.480 --> 0:18:05.240 It just gets hard to predict farther in the future 0:18:05.240 --> 0:18:07.880 because we don't know their orbits perfectly. But you know, 0:18:08.160 --> 0:18:10.680 something that's a global like like out of a movie 0:18:10.800 --> 0:18:12.960 armagedd and deep impact, something like that. If you remember 0:18:12.960 --> 0:18:17.040 those movies from thirty years ago, Now those are extraordinarily rare. 0:18:17.080 --> 0:18:20.280 Those are like every you know, tens of millions of years, 0:18:20.320 --> 0:18:22.640 like dinosaur killer impacts. Those are extremely rare. 0:18:23.840 --> 0:18:26.960 And in fact, there is an office at NASA called 0:18:27.119 --> 0:18:30.760 the Center for Near Earth Object Studies where the main 0:18:30.840 --> 0:18:33.480 job of the scientists there is to keep track of 0:18:33.480 --> 0:18:36.080 all the big asteroids in the Solar System and make 0:18:36.119 --> 0:18:38.960 sure we're not in a collision course with them. And 0:18:39.000 --> 0:18:40.600 according to their calculations. 0:18:40.760 --> 0:18:43.200 We're good for now. 0:18:43.720 --> 0:18:48.280 Now, does that mean we're totally safe? Not quite. Remember, 0:18:48.600 --> 0:18:51.440 those smaller asteroids in the fifty to a few hundred 0:18:51.520 --> 0:18:54.600 meters wide range can still come out of nowhere and 0:18:54.640 --> 0:18:57.320 do a lot of damage. But there is good news. 0:18:57.440 --> 0:19:01.720 According to doctor Plate, the good. 0:19:01.560 --> 0:19:03.440 News is we can do something about them. The first 0:19:03.440 --> 0:19:04.800 thing we have to do is find them, and we 0:19:04.880 --> 0:19:08.880 are building observatories now. The Vera Ruben Observatory takes huge 0:19:08.920 --> 0:19:11.280 images of the sky and looks for things that change 0:19:11.320 --> 0:19:13.280 from night to night. So an asteroid is, you know, 0:19:13.400 --> 0:19:14.840 in one spot, and the next night it's in the 0:19:14.880 --> 0:19:17.400 next spot. Reuben will see it. And in its first 0:19:17.520 --> 0:19:20.800 night it observed two thousand asteroids and so it's going 0:19:20.840 --> 0:19:22.480 to do this every night. So it's going to map 0:19:22.520 --> 0:19:25.439 out zillions of these things, and that's good because you 0:19:25.440 --> 0:19:27.439 want to know if one's coming toward us, or if 0:19:27.480 --> 0:19:29.360 it's orbit it's going to intersect ours in twenty years 0:19:29.440 --> 0:19:31.440 or something like that. Next thing you have to do 0:19:31.720 --> 0:19:33.560 is push it out of the way. You know, you 0:19:33.600 --> 0:19:37.280 don't necessarily want a nuke it because that's illegal and 0:19:37.359 --> 0:19:40.920 that may not do the trick. Well, is it illegal, Yeah, 0:19:40.960 --> 0:19:43.679 it's actually, the Outer Space Treaty, which was signed by 0:19:43.680 --> 0:19:46.480 a lot of nations in the sixties, makes it illegal 0:19:46.520 --> 0:19:50.159 to test nuclear weapons or detonate them in space, but 0:19:50.440 --> 0:19:52.359 in general, like blowing up a nuke and space is 0:19:52.359 --> 0:19:54.920 illegal and it's a bad idea. But on the other hand, 0:19:55.040 --> 0:19:58.520 NASA has just tested a few years ago in twenty two, 0:19:58.640 --> 0:20:03.040 twenty twenty two, to spacecraft into an asteroid. Ditamos was 0:20:03.080 --> 0:20:05.439 the name of the asteroid, a few hundred meters across. 0:20:05.440 --> 0:20:08.480 It has a moon called Dimorphos, which is one hundred 0:20:08.520 --> 0:20:12.639 and seventy meters across, and they slammed this dishwasher size 0:20:12.680 --> 0:20:16.040 spacecraft into it called DART, which was the Double Asteroid 0:20:16.119 --> 0:20:19.920 Redirection Test DART. DART. It hit the Moon at high 0:20:19.960 --> 0:20:23.720 speed and the idea was the impact would change the 0:20:23.880 --> 0:20:26.040 orbit of the Moon. And then this thing hit it 0:20:26.200 --> 0:20:28.800 and the period of that object changed by half an hour, 0:20:29.280 --> 0:20:32.760 which means we significantly changed the orbit of that asteroid. 0:20:32.800 --> 0:20:35.560 And that's good because that means that if you have 0:20:35.720 --> 0:20:38.920 enough time, like ten years lead time, you can build 0:20:38.960 --> 0:20:41.639 a rocket, send a probe to it, slam it, and 0:20:41.680 --> 0:20:43.760