Ep. 674: Asteroid Early Warning Systems

The asteroid apocalypse is one of those existential crises that keep astronomers up at night. But the DART mission showed us that we can push an asteroid off its trajectory if we have enough warning. Today we’ll talk about how humanity is building early warning systems to give us time to respond to a dangerous asteroid.


(This is an automatically generated transcript)

Fraser Cain [00:01:19] Astronomy cast. Episode 674. Asteroid early warning systems. Welcome to Astronomy Cast, a weekly fact based journey through the cosmos. We help you understand not only what we know, but how we know what we know. I’m Fraser Cain, publisher of Universe Today. With me, as always, is Doctor Pamela Gay, a senior scientist for the Planetary Science Institute and the director of Cosmic Quest. How are you doing? 

Pamela Gay [00:01:42] I am doing well. It is attempting to be spring. Here we have daffodils and mud, and apparently there’s going to be baby owls to judge by what I heard last night. It is spring. 

Fraser Cain [00:01:56] Yeah. Same here. The crocuses are finally up. The tulips and daffodils are trying, so I think I can pretty safely say that spring has finally arrived, despite being about three weeks of late. So interesting anniversary for me. Oh, tomorrow when we’re recording, this is the 24th anniversary of when I founded Universe Today. So I’ve been doing this job as on March 23rd. I have been doing this job for 24 years, which is kind of amazing. The. 

Pamela Gay [00:02:31] Universe today can rent a car. 

Fraser Cain [00:02:35] And then 25. 

Pamela Gay [00:02:37] I thought it was 24. It’s close. It can almost rent a car if it calls. 

Fraser Cain [00:02:40] For in the car. Yeah. Yeah. So so that then then that’s it. That’s like. Like then I guess it could be a Canadian senator at 35. And then I think after that, you know, it’s looking forward to retirement I guess. So, yeah. Yeah. 24 years of being a space journalist. And I’m having as much fun now as I ever did. So. So thanks for. 

Pamela Gay [00:03:03] Listening, for amazing, for. 

Fraser Cain [00:03:04] Following. 

Pamela Gay [00:03:05] All. 

Fraser Cain [00:03:05] These years. Oh, the asteroid apocalypse is one of those existential crises that keep astronomers up at night. But the Dart mission showed us that we can push an asteroid off its trajectory. If we have enough warning. Today, we’ll talk about how humanity is building early warning systems to give us time to respond to dangerous asteroid. So, like, did you didn’t didn’t you feel like humanity crossed some really important milestone when we saw the results of the Dart mission? 

Pamela Gay [00:03:39] Yes, yes. And I love that we’re starting to get these animations of what Hubble saw. And we we. Dusted an asteroid. 

Fraser Cain [00:03:53] Right. Take that space for the dinosaurs. 

Pamela Gay [00:03:57] Exactly. Exactly. It’s hilarious. 

Fraser Cain [00:04:00] Yeah. Yeah, it was. Really was. And it was like. Wow, man. Like, I it’s hard to put into words the feeling because, you know, a lot of times when you talk about these existential risks that face humanity, you go through this laundry list of nuclear war and climate change and population and all of this, and then you get into super volcanoes. Your favorite, I know, and then asteroid impacts. And I feel now like we’re almost ready to go. Whoa whoa whoa. We probably can get asteroid impacts under control. Give it enough warning time because. 

Pamela Gay [00:04:40] And that’s the. 

Fraser Cain [00:04:41] Key. And that’s the key. So now that we’ve demonstrated that we can push an asteroid, into a different trajectory, what are the plans, I guess? Well, how do we find asteroids today? 

Pamela Gay [00:04:55] So there are a number of different surveys, scattered around the planet that are each, in their own way, looking for the things that flicker, flare and move in the night. And one of the rather terrifying statistics is all of those asteroids that could do a good job destroying a town or a city. We probably only know of a few tens of percent of those objects. 

Fraser Cain [00:05:24] So we know the big ones look like the kilometer sized ones, the world enders, those we know of and have mapped. 

Pamela Gay [00:05:33] But it’s not a 100% level, though. 

Fraser Cain [00:05:37] But pretty close. 

Pamela Gay [00:05:40] We think. And and this is where where it gets frustrating because you can have objects that are in highly elliptical orbits and are extremely dark. And if they’re just on the wrong orbit synchronized with our world, we may not have found them yet. If they’re extremely dark and oriented in a bad way, we may not have seen them yet. And this is one of the major justifications for the, what was originally the Large Synoptic Survey Telescope. It’s now Vera Rubin Observatory and the large survey through space and time. And that particular observatory is going to spend ten years observing every part of the sky visible from the southern hemisphere. Right. More than 800 times. And the goal is they should be able to get to at least 60% of the city killers and hopefully 100% of the planet destroyers, the dino killers. 

Fraser Cain [00:06:47] How do we classify those? 

Pamela Gay [00:06:48] Like it’s all about size, it’s all about energy. 

Fraser Cain [00:06:52] So what is it? What is it? You know, like when we think about the Chelyabinsk, how big was Chelyabinsk? It was like 15m across. Yeah. And so when we’re up in the air. So bigger than that. 

Pamela Gay [00:07:02] Yeah. When we’re looking at, order of ten meters to tens of meters, if it blows up in the atmosphere or hits the ground, it’s going to create shockwaves, it’s going to create damage, but it’s not going to destroy anything other than what it directly hits. So like, if that size asteroid hit a skyscraper, it would be a really bad day. But hitting a farmer’s field, it’s just going to be something that is on the news for the entire planet for a week or so. Now, once you start getting up to hundreds of meters, it starts to be what is the orbit? What is the trajectory that it’s going to hit us with? And you start to worry about things like tidal waves. You start to worry about things like if it blows up in the atmosphere, it’s going to put a whole lot of energy into the atmosphere, and it could crater a town. And then once you get up to the kilometer size, that is like civilization will not have a good day, right? 

Fraser Cain [00:08:09] That is a global catastrophe. So, so really anything bigger than about 50m across, we want to know their locations and trajectory, future trajectories as far into the future as we can. And yes. And because anything above that size, you’re as you say, you’re taking out a city bigger than that, you’re taking out a continent, or you’re causing damage to a continent. And then even bigger than that and you are causing any, you know, there’s an impact that is hitting the entire planet to some degree. What you may not get hit by the actual impact or the tsunami. You may very well have your crops fail because the skies are filled with smoke for. Yeah, five years. 

Pamela Gay [00:08:58] Right. And and this this is where do you know where you’re going to be in 2029, when a certain fascinatingly named object happens to pass near the planet? 

Fraser Cain [00:09:10] Home here? 

Pamela Gay [00:09:12] Yes. 

Fraser Cain [00:09:12] It’s watching the sky when it goes by. 

Pamela Gay [00:09:17] So, sadly, where we are, we won’t be able to see it. When a Paphos goes by in 2029. It’s it’s actually going to pass between us and your typical weather or communications satellite up in geosynchronous orbit and Australia, new Zealand have a really good view. So I’m thinking I may use this as an excuse to go down under if I can figure out the finances. 

Fraser Cain [00:09:46] Right. Give a few talks, watch an asteroid fly past the Earth that way. That would be kind of epic, wouldn’t it be like standing on a stage, giving a talk, and then everybody stopping and watching this bright star fly across the sky and then. Yeah. Yeah, that would be amazing. Yeah. So. So you were starting to talk about various automated telescopes. I mean, there, I mean, there are networks of telescopes operating right now, today that are tracking as many of these asteroids and comets as they can. 

Pamela Gay [00:10:19] Yeah. So so, for instance, if you’ve heard of any of a vast number of comet Atlas, right, comets, those are all getting found by the Atlas survey, which is run by the University of Arizona. There’s Neowise, which is using the Wise telescope for a new purpose. And it’s. Out there looking for cold things moving through the sky. I all these different objects. The Catalina Sky survey, it’s another University of Arizona project. Arizona is basically working very hard to keep us safe, but they have very large a crater. They know the consequences. That’s a joke, people. So we have Catalina Sky survey. We we have all these different telescopes that are out there in a variety of different sizes. The Zwicky Transient Facility is working out in California, and they are imaging regions of the sky that basically as much as they can, giving priority to the parts of the sky that are most likely to have asteroids and comets. So things near the disk of the galaxy are given priority, and they’re looking for anything new that isn’t already categorized. And they are putting out alerts when new things are found. And coordinating through the Minor Planet Center out in Boston, which is organized by the International Astronomical Union. And they’re working to, as quickly as they can, refine the the orbits that we have for these objects, because we keep periodically finding things that when we get their initial orbit, we start by, okay, we see it moving like this, fit a circle to that, assume lots of error, and then figure out over time what is within range of all that error. And as we get more and more observations that change in velocity across the sky that we see corresponds to our own motion and the asteroid’s motion, and it gets to the point that only one orbit can fit the motion that we’re seeing of that asteroid. And the Earth’s orbit is well understood. And in the interim, though, between going from the approximating it with a circle to accurately well known orbit, occasionally we find things that look like they’re going to hit the planet and things are given a great deal of observational priority, I guess is the. 

Fraser Cain [00:13:03] Best way to put it. Yeah. And they actually there’s one right now and I forget the designation of it, but it was found on Valentine’s Day. 

Pamela Gay [00:13:12] It’s coming Valentine’s Day. 

Fraser Cain [00:13:15] Or it’s coming Valentine’s Day. That’s right. Yeah yeah yeah yeah in 2046. 

Pamela Gay [00:13:20] So let me pull up the information anyway. 

Fraser Cain [00:13:23] But this happens all the time that that astronomers find some object. They run their initial calculations and they go, oh, right. There’s the the future orbits of the asteroid. One of them crosses the Earth or is within a certain error bar of crossing the Earth, and then they go, oh. And then they call all their friends and say, could you double check my observations and, and keep tracking this asteroid so that we can all agree that this thing isn’t going to be a danger? This is what happened to a face like, you know, you are all familiar with the prophecy because it was going to be making this close flyby in 2029. And then I think a few years later, it’s going to come back around and had a chance. 

Pamela Gay [00:14:04] And Charlie Maris. 

Fraser Cain [00:14:06] And now that chance has been dropped to zero, that enough observations have been made that we know for sure that this asteroid is not a threat to us in the foreseeable future. But why? 

Pamela Gay [00:14:18] It’s, it’s it’s amazing what we’re capable of finding. So. So the current culprit in rising to the potentially dangerous asteroid list is 2023, D.W.. And on Valentine’s Day 2046, there is still in a one. And I am not finding the most accurate to the moment numbers. But, as of last week, it was 1 in 607 chance right. Smacking us, which in the grand scheme of things is is enough that we pay attention. It’s 2046 that we have to worry, and we now know we can nudge these things by smacking them with heavy objects. 

Fraser Cain [00:15:04] Yeah. Which is. 

Pamela Gay [00:15:05] Satisfying. 

Fraser Cain [00:15:06] To 100%. Yeah. Take that asteroid. And so like when you hear people talk about this, like, if the astronomers found a dangerous asteroid, would they alert the public? And the answer is absolutely. 

Pamela Gay [00:15:23] Yeah. 

Fraser Cain [00:15:24] And the way they would alert the public is we found an asteroid that has a 1 in 1000 chance of getting close to the Earth. Could everybody please do following observations? Everyone does. And they go, oh, now we found that it has a 1 in 100 chance of impacting the earth. Now, we found that it has a 1 in 10 chance of impacting the Earth. Now we found it has a 50% chance of impacting the Earth. 

Pamela Gay [00:15:45] And so we are launching things out and. 

Fraser Cain [00:15:47] We’re starting to watch things in its direction. And so we will all see this. Story unfold in mostly real time as astronomers become more and more certain of what the future holds for this asteroid. And and and look, you know, across sites like everything like, did we find life on Mars? Did we find life on exoplanets? Like they are all. You get a hint, then you get confirmation, then you get another paper. Then someone claims it’s not true and just goes on and on and on. It all unfolds in real time, right in front of you. It is impossible to for astronomers to keep their mouths shut, so don’t worry about it. 

Pamela Gay [00:16:30] Yes. So. So there is the we can’t keep our mouths shut problem. Except somehow with gamma Ray burst 2017, they most clearly kept their mouths shut. That still shocks me. There are a lot of graduate students whose lives were threatened, I suspect. 

Fraser Cain [00:16:45] Yes, thousands of coauthors on the paper. And yet they somehow kept it out of the press. Yeah, I was that was pretty impressive. 

Pamela Gay [00:16:52] It was spectacular. But we’re with things like asteroids. The issue is you also have all the asteroid hunters out there who are largely amateur astronomers. These are people of means who have bought their own telescopes that range from your standard 16 inch up to a meter class telescope, and they’re out there night after night, taking gorgeous images and looking for the things that move, reporting what they find to the Minor Planet Center because they’re hoping to get the discovery credit. So if if it’s not just the amateur astronomers out there with our automated surveys, but also hundreds to thousands of people scattered across the entire planet, where we see things getting discovered by Hungarian astronomers, Japanese astronomers. It’s it’s people all over the world. 

Fraser Cain [00:17:51] Now, we had a really great test of the existing asteroid early defense system, actually multiple tests. So so you’ve been following these these stories? 

Pamela Gay [00:18:02] Yeah. So so a few weeks ago, there was what may be my favorite tweet to come out of the, ESA, operations Twitter feed. And it basically amounted to. So, if you go outside at this time, you’re going to see a fireball go through the sky. Don’t worry about it. It’s settled in. Much fancier words will be a screen capture of the tweet up on our website. And this was a matter of a amateur astronomer discovered it, reported it, it got confirmed. And then this fireball streaked over the United Kingdom and France. And because of all of the dash cam videos and people reporting what they saw and their phone videos, they were able to narrow down to a few square blocks, basically where this sucker hit, and it was a school kid that found the first notable fragment. And these were not small fragments. They weren’t deadly fragments. They were cool sized fragments. And it was just awesome. 

Fraser Cain [00:19:14] Now, have you ever seen a fireball? Yes. With your own eyes. 

Pamela Gay [00:19:18] Yes. But it’s they’ve never been, like, the kind that people go out and find things. There was one time I was driving down the highway in California, which is not when you want to see a fireball, by the way, folks and things streaked through, and I had this moment of, I, I want to watch it and not the road, but I had to watch the road. And that made me sad. Yeah. And then I’ve seen bullets during meteor showers. Yeah, I had I have you. 

Fraser Cain [00:19:46] I’ve seen one bolide during a meteor shower similar to you, you know, bright enough that that, you know, you probably could have read a book to the light of it, but not like turned night today, the way some of those can. So and I’ve seen one and like I’ve spent you know, here I am now in my early 50s. I’ve been out many nights and that’s all I’ve seen. And so like this network exists today that, that astronomers around the world, as well as all of these robotic telescopes, are scanning the sky constantly looking for anything they are as soon as they make an observation, they are providing info into this common database and people are doing confirmation views. They are reporting them to each other. They are then announcing to the public when and where one of these objects is going to strike the atmosphere to the level. And this is the part that just blows my mind that you can stay on top of these alerts and go, hey honey, do you want to go see a fireball exploding? The atmosphere that it should be fun. Yeah, let’s do it. Until you hop in your car, drive six hours, walk outside closed door, pull out your cup of coffee, look to the sky, check your watch, and then boom, the sky explodes. And that is never been possible in human history. And yet we are moving to this world where we’re watching. Asteroids or meteors explode in the atmosphere is the kind of thing you can do on a lark, because you’ve you’ve got this level of of information. It’s it’s crazy and yet entirely feasible at this point. This is all great, but we have some blind spots, and NASA and the European Space Agency are looking to fix these. 

Pamela Gay [00:21:42] So most of the surveys that I’ve mentioned so far, Catalina, the Zwicky Transient Facility. These these are northern hemisphere facilities, or at least a lot of our facilities are Northern Hemisphere and Hawaii, which is northern hemisphere, but can get a lot of the southern hemisphere. What we don’t have is anything of the. Meter class and larger. Southern hemisphere dedicated to doing that night after night after night that we need. And this is where the the very room and observatory and it’s survey of space and time. While asteroids are moving through space and time, and with its capacity to catch things moving and changing in brightness, it should be able to catch asteroids of sizes that we haven’t been able to regularly catch before. This is a many meter telescope that’s going to be sensitive down to 24th magnitude and fainter, depending on what filter you’re using. 

Fraser Cain [00:22:59] And it’s going to find, I’ve heard like 90% of the dangerous asteroids that are out there just within a couple of years. It will just that it that’s that’s within its area. It’ll kneel down. 

Pamela Gay [00:23:11] And and there’s folks thinking that if they can extend it just a couple of years, they’ll be able to get all of the down to wrecking a small town asteroids, at that 90% level. And and so here’s to hoping that it does ten years and then does another couple years and and it’s this. Triple threat of massive merger with huge light collecting area being designed to image fairly large areas of the sky with massive specially made cameras, they’re having to develop teraflop computers to deal with this, the. 

Fraser Cain [00:23:56] Most powerful digital camera that’s ever been made. 

Pamela Gay [00:24:00] And then looking at everything with a cadence of every few nights for the entire visible sky from its location that is going to allow us to do things we just haven’t done before. The thing that I am most looking forward to, and I suspect that there are others who are even more eager than I am, is if there are other large planets out in the Kuiper Belt, it’s going to find them in short order. Yeah. Michael Brown has has basically said if he can’t find my my potential planet. It’s not getting fat, right? And and all of space. It’s going to get our whole solar. Yeah, it’s kind of awesome, you know? 

Fraser Cain [00:24:48] Now, we don’t have time for me to observe that you have been talking about a telescope that doesn’t exist yet, because we have to move on to some other telescopes that don’t exist yet, but I think are important for us to talk about. 

Pamela Gay [00:25:02] It doesn’t have to be like. It’s not going to potentially blow up online. 

Fraser Cain [00:25:06] Your rules make no sense to me. But NASA is working on the Neo surveyor. The European Space Agency is working on its version, and hopefully within a couple of years, we should have space based telescopes that deal with one of the big blind spots of these ground based observatories, which is seeing stuff that’s close to the sun. 

Pamela Gay [00:25:30] Yeah. And this is one of the most terrifying things, actually, because the things that are going to be most dangerous are going to have orbits where they are moving around the sun with us. So, so if we’re going around and around the sun and something has a slightly elliptical orbit and it catches up with us, or something is in front of us and we plow into it, the velocity difference is going to be a bad day, but it’s not as catastrophic. Now, if instead we’re going around the sun and something else is like, I should cut very, very close to the sun and essentially approach our orbit at a right angle. Yeah, it’s going to, first of all, not get readily noticed because we don’t point telescopes near the sun, because the telescopes don’t behave well in those conditions. 

Fraser Cain [00:26:25] They catch on fire. 

Pamela Gay [00:26:27] They catch other things. 

Fraser Cain [00:26:28] Yeah. Exactly. Yeah, yeah. 

Pamela Gay [00:26:31] And and then the difference in velocities is just going to make the transfer of energy from that asteroid to our Earth a little bit worse than we might like. By which I mean, it’s it’s really bad. It’s really those are the ones that are going to get us if anything gets us. 

Fraser Cain [00:26:48] And so we’ve got two missions that are going to be launched in the next couple of years. One, as I mentioned, Neo surveyor, I forget the name of the European Space Agency’s one. Two going to work in tandem, fly to various Lagrange points and observe in infrared these objects in that in asteroids are the perfect target to detect in infrared that they can then do follow up observations. And so when you think about that future, we will have Vera Rubin. We will have multiple space telescopes searching for asteroids. We will pretty confidently know the location and future trajectory of effectively, every dangerous asteroid that is out there in the solar system, which is like if you have a big list of existential risks, you can literally just scratch this one off. 

Pamela Gay [00:27:41] We just need to make it like 15 more years. Just 15 more years. Yeah. 

Fraser Cain [00:27:45] And so, like, if the robots will let us get there. If if you know climate change laws make it, then yeah, we’ll be able to to knock that existential risk off of the list. 

Pamela Gay [00:27:58] And it’s going to be machine learning algorithms that are finding them and figuring out the orbits for us. And that’s just kind of awesome. We are going to be protected by the machines. 

Fraser Cain [00:28:10] Perfect. Thanks, machines. And thanks, Pamela. 

Pamela Gay [00:28:12] Thank you Fraser, and thank you. Everyone out there who is is part of making our show possible. We sadly don’t have time to thank all of you by name, but this week we are going to continue our journey through AI. We have different tiers on Patreon and there are tiers where you get your name read. So this week I would like to thank Scott Cohen, Kimberly Reich, Daniel loosely, Marco Ursa, Matthew Horstman, DFM, Jeff Wilson, Gregory Singleton, Felipe. Walker, Tim. Gerrish, Matthias. Hayden, Claudia mastroianni, Justin Proctor, Tim Mac n conception. Flacco. Jesus. Trina. Cooper, Janelle. AKA Veronica cure. Benjamin. Mueller, Omar. Dal. Riviera. Jay. Alexander. Sun. Iran. Zagreb, Kenneth. Ryan, Don. Manders, Michelle. Cullen, Dean. McDaniel, Paul. De Disney, Scott. Briggs. Ninja, Nick. Share some Michael Regan, Peter Matt. Rucker, Jim McGann. Frodo. Tannenbaum, father. Prax. Brant near Knop, Philip. Grand underscore, Bruce. Amazing, Michael. Steven. Rusnak, Dwight. Ilke and Semansky. And to our patrons, we offer you shows with no ads, so check it out if you want to escape the ads and help us support all the people behind the scenes that keep our website up, that edit our audio and video. And it’s not just Frasier and I. We just show up and report. It’s other people who make this happen and you let us pay them. 

Fraser Cain [00:29:58] Thank you. Thanks, everyone. I’ll see you next week. 
Pamela Gay [00:30:01] Bye bye. Astronomy cast is a joint product of Universe Today and the Planetary Science Institute. Astronomy cast is released under a Creative Commons Attribution license. So love it, share it, and remix it, but please credit it to our hosts, Fraser Cain and Doctor Pamela Gay. You can get more information on today’s show topic on our website. Astronomy. Cars.com. This episode was brought to you. Thanks to our generous patrons on Patreon. If you want to help keep the show going, please consider joining our community at Patreon.com Slash Astronomy Cast. Not only do you help us pay our producers a fair wage, you will also get special access to content right in your inbox and invites to online events. We are so grateful to all of you who have joined our Patreon community already. Anyways, keep looking up. This has been Astronomy Cast.