Ep. 672: Space Debris Removal

We’ve talked about the rising problem of space junk. Okay, we know it’s an issue. So what can be done about it? Today we’ll talk about ideas to remove space junk, making sure space is open to use for the centuries to come.


(This is an automatically generated transcript)

Fraser Cain [00:01:49] Astronomy Cast episode 672. Space debris removal. Welcome to Astronomy Cast, her weekly facts. Space journey to the cosmos, where we help you understand not only what we know, but how we know what we know. My name is Fraser Cain. I’m the 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. Hey, Pamela. How you doing? 

Pamela Gay [00:02:11] I am doing well. I just got home from a wonderful few days, Dustin Gibson, Ian lauer. They taught me how to use some of the telescopes out there and shout out to them to actually bring in the clear skies. I don’t see those very often. 

Fraser Cain [00:02:27] So you had clear skies and you were around telescopes? 

Pamela Gay [00:02:30] Yes, yes. American. I heard pigs flied. Yeah. Moon. I don’t know the best chance of that right now. 

Fraser Cain [00:02:37] Winter continues here on the west coast of Canada. My wife shared a post on Facebook where it said, this isn’t winter anymore. This is harassment. I thought I thought that was perfect. Yeah. Like, yes, I’ve got I’ve got a couple of inches of snow on the ground here in mid-March. That is deeply unusual, except for last year, which was also deeply unusual. But even that still was gone last year. So yeah, this is just this is just sick and wrong. I am I have fruit trees to grow. I’ve got things to plant. I need the weather to behave. 

Pamela Gay [00:03:18] Yeah, yeah. I’m sorry. 

Fraser Cain [00:03:23] We’ve talked about the rising problem of space junk. Okay. We know it’s an issue. So what can be done about it? Today we’ll talk about ideas to remove space junk, making sure that space is open to use for centuries to come. So we’ve gone on and on complaining, whining. Wow. Our space junk. There’s too much debris up there. Kessler syndrome will never leave trapped eternally. Define what somebody’s going to do about this. How do we start this? 

Pamela Gay [00:03:50] It basically comes down to we need a, giant space ball style vacuum cleaner to to grab all of the junk. And failing that, people are going up with various, versions of grappling on with arms, deploying magnets. And there’s even, like, if you’ve ever played flag football where you pulled the flag off of somebody and knocked them out, well, we’re looking to do more of the pin, the tail on the donkey version of that. We’re sticking flags onto bits of debris to give them extra drag. And there are so many ideas. 

Fraser Cain [00:04:31] All right. We’ll go through these ideas bit by bit. But but let’s start with what I think is the best idea, which is don’t produce space junk in the first place. 

Pamela Gay [00:04:42] Yes, exactly. 

Fraser Cain [00:04:44] So how do we minimize, I guess, what part of a spacecraft of a launch generates space junk? 

Pamela Gay [00:04:53] It all depends. But we we currently have as forms of space junk, the second and higher stages of rockets that instead of falling back to the atmosphere and self-destructing the atmosphere, have instead decided in orbits a good place to be, right? We have defunct, satellites that are just hanging out, being dead and, steerable. We have things that have fallen off all manner of mission, been dropped by astronauts. And then unfortunately, there’s also the debris that either came from missions that self-destructed on deployment or were quite purposefully split apart by various nations testing their ability to do harm, or things colliding. 

Fraser Cain [00:05:47] And I guess one of the biggest is the is the spent boosters. When you think about a rocket launching, you have the first stage launching, and then the second stage takes over and the second stage continues to fire its engines until it has put the spacecraft into essentially its final orbit. But that means that it is also in that final orbit. And so the the payload and the booster then continue on. And these boosters can be gigantic. I mean, they’re as big as school busses and they’re orbiting around the Earth. 

Pamela Gay [00:06:21] They occasionally get mistaken for miniature asteroids that we have caught in our orbit. And no, they’re just boosters. 

Fraser Cain [00:06:29] And then you’ve got and so the first stages, they either land back on a barge or burn up in the atmosphere, the fairings will crash into the ocean but be. 

Pamela Gay [00:06:41] Caught. 

Fraser Cain [00:06:41] Or be caught. Yeah. But that it’s that second stage. Yeah. And you know, even potentially a third stage on say the Saturn five. They’re still out there in many cases as you say they are, they are orbiting the sun and are confused. The people are confused and think it’s an asteroid. So what can we do to minimize boosters, dead satellites in the end, with some preplanning, how can we help these objects take care of themselves? 

Pamela Gay [00:07:12] Well, they’re there’s basically three different strategies for getting rid of the boosters. The simplest would be having them retain or have in a different system, just enough thrust that they can send themselves back down through the atmosphere. Alternatively, if they’re only going to low-Earth orbit, you can have them have drag systems that cause their orbits to decay significantly faster. 

Fraser Cain [00:07:42] And we’ve seen some tests recently with this technology. 

Pamela Gay [00:07:45] They’re super cool and they’re super bright. So on one hand, it’s really cool to look up and know that bright streak of tether up there that I can see with my off the shelf telescope is is a satellite doing something cool the same time though it it is a bit problematic, but launches at least aren’t as common as communication satellite constellations. 

Fraser Cain [00:08:08] And there was a recent test, of a European Space Agency mission. They deployed this little ten centimeter cube drag sail on to the mission, and then it flew up, performed its functions, and then it deployed this drag seal that kind of looks like a solar sail. Yeah. And then what would have taken five years for it to the orbit? It only took one year because it had a much larger drag coefficient with the Earth’s atmosphere, and it cleaned itself up. So imagine them putting these modules on every single spacecraft that’s designed to work in low-Earth orbit. But as you say, it’s got to be low-Earth orbit. You got to be interacting with. 

Pamela Gay [00:08:49] With the atmosphere. 

Fraser Cain [00:08:50] With the atmosphere, or it’s not going to function. 

Pamela Gay [00:08:53] And I really think that using lightweight materials to create large amounts of drag is the easiest way to go. Unfortunately, it’s not an entirely predictable process, which means that you have to do a lot of effort. First of all, knowing the orbit for these itty bitty little tiny things and then seeing how they change. And as we approach solar Max, our atmosphere is going to be changing in size on the regular as we’re struck by energetic particles from the sun. So there there is going to be a new level of chaos in this upcoming solar max that we haven’t seen before, as we have more and more low-Earth orbit communication satellites, more and more CubeSats, right. And a misbehaving atmosphere. 

Fraser Cain [00:09:47] So then let’s imagine a. Nation, where someone has launched a booster or a satellite that doesn’t have any method of returning itself back down to Earth. Could we rescue it? Could we send up something to deorbit it later? 

Pamela Gay [00:10:11] Yes, and there’s been some initial tests of this technology already that that I think is super cool. This this is where we had back in 2020, the alpha demo. And I would love to know who managed to come up with this. It stands for end of life Services by Astro scale. And during their demonstration, they carry it up with a second satellite that they ran their tests on, and they let go of it and they initially just caught it. They let it drifting, caught it, and they were practicing over and over. Just how hard is it to catch a satellite in these different scenarios, like a. 

Fraser Cain [00:10:54] Cat playing with a mouse? 

Pamela Gay [00:10:56] Exactly. 

Fraser Cain [00:10:57] Are you catching it? Yeah. That’s cool. 

Pamela Gay [00:11:00] And as your skill is very much planning a one for one kind of system where you launch up one of their satellites, it magnetically grapples on to something, and then it and the something it grabbed both come down out of orbit. So so that that’s one way of doing it. I personally am intrigued by some of the new plans that are coming out of a UK funding challenge where they’re saying, okay, we want things with arms that will grab things, and I can imagine a future where you have robotic arms, grabbing things and hurling them towards the atmosphere. I don’t know quite how the angular momentum will work on something like that, but it amuses me. 

Fraser Cain [00:11:45] But at least grabbing them with arms, latching on and then firing the thruster and then carrying it and its payload into the atmosphere. 

Pamela Gay [00:11:55] And and the other big set of examples we had came from Northrop Grumman, where back in February 2020, they docked on to an Intelsat that was above geostationary orbit. This was a parked and left for dead mission, and they successfully grabbed it and brought it back down to geostationary orbit, where it could continue doing its job. Another test they did was in April 2021. This was their mission extension Vehicle two, and they docked with another Intelsat, this time NGO, which is an extremely crowded area of orbit. 

Fraser Cain [00:12:39] And it’s a big space. 

Pamela Gay [00:12:41] It’s a big space. But they proved that they could successfully navigate within this region and extend the life of satellites. And if you can extend the life of satellites by either refueling them or adding something onto them that has that additional fuel, you can extend their life and you don’t need to launch more, in fact. Yeah, and the best way to avoid junk. 

Fraser Cain [00:13:08] It’s like buying an older car and maintaining it. And that means that you don’t need to buy a new car, which removes one additional car from the road. So it makes a ton of sense if they can rescue these older satellites that that have just merely run out of propellant, but they’re still functional, or they’ve lost their guidance system or whatever you can attach, you can bolt on this, this, I don’t know, parasite satellite. Right. That then performs those additional functions like, you know, it has propellant on board. It has guidance systems. It has a better communications array whatever that can then fix whatever is the problem of that satellite. It’s a it’s an elegant solution. Yeah. You would imagine instead of spending $500 million to build an entirely new communications satellite, you just send up a $20 million. Propellant. Take that with arms that that latches on and then performs that function. I love the idea. 

Pamela Gay [00:14:13] And imagine a future where instead of moving the entire propellant tank, which would have to be pretty big, you park in some middling orbit 14,000 miles up or something, and you have a giant refueling tank that can itself be refueled from Earth, and then a small army of little robots that can grab on to things. And, and potentially we figured out how to refuel aircraft by simply making sure that they had the right nozzles to grab on to each other. Now, if we can figure out how to build spacecraft compatible with refueling satellites, we will have a future where there’s just this. Flock is the best word I can think of, of little boosters that simply do all the Hohmann transfers in the world to get from one orbit to another and refuel these things. And that’s the future. I want an army of small grappling robots that refuel things. 

Fraser Cain [00:15:23] Yeah, I mean, the non reusability of spacecraft today is still kind of crazy. And yeah you know Musk would always make this analogy be like imagine if your airplane every time you flew your airplane you destroyed it and bought a new airplane. It would make trips to Europe very expensive. Well, to push that analogy further, imagine if inside that airplane was your car and you would drive the car out of the airplane while the airplane was lit on fire, and then you would drive your car until it ran out of gas, the one tank of gas, and then you would walk away from the car, which is madness. So yeah, you could if you could maintain, restore the satellite, and then if you could then design them to, to make this process very easy, pull out the main bus, swap out the reaction wheels. You can just imagine this scissor armed. 

Pamela Gay [00:16:15] Yeah. 

Fraser Cain [00:16:16] Spacecraft with all kinds of parts on board, sidling up next to the to the satellite having problems and sort hot swapping out parts. 

Pamela Gay [00:16:26] Yes. 

Fraser Cain [00:16:27] I love that future. 

Pamela Gay [00:16:28] Yeah, this this is the future I want now. All the things that we’ve talked about so far though, they only apply for things that are big, essentially. Right. And the scary stuff in orbit is that millimeter, two centimeter level stuff. 

Fraser Cain [00:16:47] All right. So let’s get scary. Let’s talk about the little stuff. 

Pamela Gay [00:16:51] So as as we thought initially occurred with the Mars 22 capsule on the International Space Station, you can get stuff that is millimeter size moving fast enough that it can puncture spacecraft. And this is disturbing, because once you get down to millimeter, you can’t if it’s moving in low-Earth orbit, see it at all. It’s it’s you just you can’t discover it. 

Fraser Cain [00:17:21] Yeah. Ground tracking stations are tracking tens of thousands, close to 100,000 objects that are one centimeter or bigger. And when you think about, say, a bell curve, there’s this whole region of stuff that is smaller than one centimeter that is still very dangerous. A thing that is half a centimeter across hitting a spacecraft is a very bad day. 

Pamela Gay [00:17:46] Yeah. And and this is where you have to figure out how do we go out and catch stuff with a craft that. If you match speeds wrong. If you do it wrong, you’re going to end up sending your space cleaning mission tumbling, spinning. Perforate it. 

Fraser Cain [00:18:11] Right. 

Pamela Gay [00:18:11] And becomes. 

Fraser Cain [00:18:12] Part of the problem. I mean. 

Pamela Gay [00:18:13] Yeah. 

Fraser Cain [00:18:14] Like, let’s just talk about the energies involved here, right? These spacecraft are going, ten ish. I forget what’s what’s orbital velocity, like 28,000km an hour. Yeah. So. So let’s say you’re off by 1000km an hour, will you? Clatters a spacecraft with a piece of debris. At 1000km an hour, it will potentially destroy it and cause a whole new cloud of debris. So you can’t get this wrong. 

Pamela Gay [00:18:48] And this is where folks are starting to look at ideas like using magnets, which will hopefully make the speeds make sense, doing matching orbits to try and grab things. It all started actually in the mid 80s, when NASA had the idea to basically grab things with like the idea of running around with a giant tarp, except it was a spacecraft and catching things inside of it. It’s just it’s gotten more and more complex, and one of the difficulties is we have things going in a whole range of different directions. Right? Planet. 

Fraser Cain [00:19:33] Yeah. Like, let’s stop on this end because I think this is the heart of of what everyone in their mind is at least thinking about solutions to this problem right now. But like, let’s I just want to I want to just really hammer home the scale of this issue. You’ve got close to 100,000 objects. Yeah, each of which is traveling around the Earth at 28,000km/h. If you approach this object not exactly the same speed. Yeah. You are either going to shred the piece of debris or your spacecraft adding to the problem. And so if if you said to a mission planner, I want to recover this one meter chunk of metal from space, they’d be like, no problem. All we need to do is design a $50 million spacecraft with robotic arms, put it on top of a $100 million Falcon nine launch. So you’re looking at $150 million mission. It will fly out to this one meter piece of debris, grapple it with its little arms, and then hug it close and the two will reenter the Earth’s atmosphere together. All right. So that all. 

Pamela Gay [00:20:43] The investment of money. 

Fraser Cain [00:20:44] Well, that throwing out, I mean, you cleaned space, you spent $150 million and you removed one little chunk of metal. And the problem is, is that if you want to remove a different chunk of metal, you need a different $150 million mission to go get that piece of metal. Yeah. And just add those numbers up like, like there is no easy way to just collect all this stuff. Yeah, with one spacecraft, because each one requires a change in velocity, and you need to add propellant to your spacecraft to go after each one of them. It’s a it’s a thorny problem, that we like it away from us. Yeah. So what’s the solution then? What’s. What are the ideas? To remove the debris in a way that doesn’t require, a multi hundred million dollar project for each piece of debris. 

Pamela Gay [00:21:38] Right. So, so for the smaller stuff, folks are still working on the idea of coming very close to matching the orbital speed and just. 

Fraser Cain [00:21:47] Scoop. 

Pamela Gay [00:21:48] And scoop. So you can imagine a set of, of processing orbits that go from a little bit closer to the Earth to a little bit further out, so that as you’re going through any given orbit, your speed is just slightly different from the stuff in that orbit, right? Allowing you to catch it. But you have to be close, and you can only catch things that are in a very close orbit. So you could have a mission that it’s a little bit in and it’s a little bit out is moving over time, and it just keeps grabbing a little bit more and a little bit more. 

Fraser Cain [00:22:23] Right. And it uses a little bit of propellant each time to slightly change its orbit to grab the next piece. And so you could you could mathematically work out this latter of of orbits. Yeah. And hopefully instead of you spending $200 million to collect one piece of debris, you could spend $200 million to collect a hundred pieces of debris. 

Pamela Gay [00:22:44] And this is like flying around with a spider web, essentially, where you just keep catching things and trying to catch it in something that is exceedingly flexible. Just like a spider web, when a fly hits, it brings that fly to zero velocity very quickly. Right. Well, in this case, it has to bring it to a matched velocity very quickly. So trying to build something that can have all the needed maneuverability and all the needed flexibility, these are the things folks are thinking about. And and then for the middle sized staffing, just tag them like a game of pin the tail on the donkey. 

Fraser Cain [00:23:21] But it really sounds like I mean, I like that idea tag. Take them like maybe even from afar. Like you could. Yeah, you could fire some kind of, backpack at them that contains their drags here. Right, right. And then or tether. There’s something that that you could, you could. 

Pamela Gay [00:23:39] Increase their drag. 

Fraser Cain [00:23:40] Right. And this has been this has been proposed again. But I like I’ve got I’ve got to say when you think of the scale of the problem. It is like going into a war zone and collecting all the bullets in flight. 

Pamela Gay [00:23:55] Yeah. 

Fraser Cain [00:23:55] And end. Could it be done? Yes. Theoretically, you could chase down all of the bullets that are being fired. You know, we need Magneto. 

Pamela Gay [00:24:05] We really need these. 

Fraser Cain [00:24:06] But nobody is going to take on that expense that everybody is just going to turn back and go, nope. This stuff. So. So lasers to the rescue, right? 

Pamela Gay [00:24:17] That is one thing that folks have talked about is using lasers and light pressure to move things around. That, again, is another high energy thing. 

Fraser Cain [00:24:29] So how would this work? 

Pamela Gay [00:24:30] So the idea is we don’t think about it, but all the lights that are currently shining on me in the studio are exerting a force on my body as the photons collide with the surface of my skin. Now, if you thought something with a powerful enough laser that that energy is either going to get transformed into melting something, you can usually write in chocolate with a strong green laser. This is something I enjoy doing. That’s cool. Or if it’s a highly reflective surface, that laser light will hit the surface, transfer all of the momentum from the photons and cause that surface to move. And so this is like slowly moving something with a water gun, except those water drops from the gun have a whole lot more mass than those photons, but they’re moving slower. So I mean, it’s it’s a strong enough laser on a reflective enough surface. You can move things. It’s again, high energy, but it’s also highly focused. 

Fraser Cain [00:25:36] So right. 

Pamela Gay [00:25:37] One more idea to add to the arsenal. 

Fraser Cain [00:25:39] And that’s I mean that’s to bounce things off. But the other idea is to oblate. And I like that idea as because it’s a lot more effective. 

Pamela Gay [00:25:49] Yes. I was just going to say the idea of a blading is, is you basically are removing layers of the material until it is no more. 

Fraser Cain [00:25:57] Well, but also it acts like a propellant. So you fire a high enough power laser at a piece of debris as it’s flying near by you, you vaporize a little chunk of material off the surface of the object that turns into a tiny little propellant stream that gives the debris a kick in the opposite direction. And so now it’s as if the piece of debris has fired its own little rocket to slow itself down in the direction. 

Pamela Gay [00:26:24] You can drive. Tiniest ion drive. 

Fraser Cain [00:26:26] Right. Exactly. The tiny, tiny drive. And what’s great is that the laser can just sit there and then just fire at different targets as they go by, one after the other, without having to change its orbit. So you just wait. 

Pamela Gay [00:26:39] I love that there’s so many different ideas on how to do this that when you said oblate, I went to the okay, let’s destroy millimeter targets, right? And you went to the let’s create a tiny hole on something to get it to move. 

Fraser Cain [00:26:52] Yeah. 

Pamela Gay [00:26:53] The ideas are almost as numerous as the space junk, and we just need someone to break down and start paying to do it. 

Fraser Cain [00:27:01] So there have been a couple of papers that we’ve reported on at Universe Today about these ablative lasers. Most of the ideas are coming out of China. And so like a laser capable of reaching out tens of kilometers, perhaps even hundreds of kilometers in space with enough power to vaporize a little piece of titanium. 

Pamela Gay [00:27:27] Well, the terrifying. 

Fraser Cain [00:27:28] Is kind of terrifying. Yeah, yeah. Would you be all right having that in orbit overhead? 

Pamela Gay [00:27:33] I feel like that breaks the outer space treaty somewhere. 

Fraser Cain [00:27:36] Like. I mean, it’s on nuclear power. 

Pamela Gay [00:27:38] Trying something from a kilometer away. That’s like a good, safe orbital separation, but closer than a kilometer that. Is uncomfortable. 

Fraser Cain [00:27:48] Yeah. And so you can like obviously it doesn’t you know, any nation who proposes this idea is going to get a lot of pushback from the other nations, because you could just turn this thing around and start shooting it at others and functioning satellites and take them and make them non-operational. You could turn it off the ground and find things that are pointed in space. So there’s a lot of downsides, but then you could also use it to send off your probes to Alpha Centauri. So that’s cool for Breakthrough Starshot. So I think, you know, there are challenges that that we’re going to have to face to be able to come up with this problem of all of them. I think this technology is the is the one that will be most effective, but it’s also the one that’s the most politically problematic, because anyone who launches this thing has a lot of dangerous capability in space. 

Pamela Gay [00:28:45] I’m just going to keep going with the pin, the tail on the donkey idea. Let’s let’s just do that. 

Fraser Cain [00:28:49] Don’t do that 100,000 times. 

Pamela Gay [00:28:52] Sure. It could be fun. 

Fraser Cain [00:28:54] I think it’s fun for the aerospace industry to create an endless fleet of spacecraft. Maybe. But, yeah, it is like there was an estimate that I read that we need to remove five defunct satellites a year. 

Pamela Gay [00:29:14] Yeah. 

Fraser Cain [00:29:15] To keep up with the amount of new satellites that are being launched, as well as the amount that are naturally just orbiting themselves because of atmospheric drag. And if we don’t do that, then this problem is just going to get worse and worse and worse over time. 

Pamela Gay [00:29:31] Yeah. It’s a scary time. 

Fraser Cain [00:29:33] Yeah. Yeah. And, and and I think like, we imagine this idea of, like, one day we’re going to wake up and find out that the earth is now enclosed within an impenetrable shield of. 

Pamela Gay [00:29:44] No. 

Fraser Cain [00:29:45] Shrieking debris, but it’s just wear and tear. 

Pamela Gay [00:29:48] Have you ever seen or been part of one of the truly massive, car pile ups that starts with, like, one car going high speed hits another car? Yeah. People start slamming on their brakes, which triggers more accidents, which triggers more accidents. And and sometimes of the road isn’t that busy. The one accident, it’s just those two cars end up off in the medium and everyone slows down to to lollygag because that’s what humans do. The Kessler syndrome is going to be something like that, but much slower, where first you have a defunct satellite, hits another satellite, and it creates a little bit of debris that spreads out over time. And some of that debris may be months, maybe years later, hit something else, and it’s going to add up and hopefully give us time to panic and actually invest money in things that people aren’t investing money in. But it would be cheaper to invest now than to have to do it fast tracked in the future. 

Fraser Cain [00:30:57] Yeah, yeah, yeah. I mean, there’s like all of these environmental problems that humanity faces. The best thing to do is face the problem head on today. Invest what it’s going to take to minimize the consequences downstream. 

Pamela Gay [00:31:13] Yeah. 

Fraser Cain [00:31:15] Will we do it? History says no. 

Pamela Gay [00:31:20] You’re right. 

Fraser Cain [00:31:21] And on that happy note. Thank you Pamela. 

Pamela Gay [00:31:25] Thank you, Fraser. And, thank you to all of our patrons who allowed us to create this ends on a very sad note episode. You make everything we do possible, and and I just want to say thank you this week to planetary. Shawn. Maps. Andrew Stevenson, G-Force 184. Alex Ray and the mysterious Mark James. Roger. Powell. Hayden. Karthick. Becca. Trombone. Glen McDavid. Benjamin. Davies, Cami. Thracian. Gabriel. Gelfand, Dean Steven. Kelsey, the air major, Jon Ossoff, Bart Flaherty, Sam Brookstone, his mom Nate Detweiler, the lonely sound person Brian Kelby, nulla Lee Zeeland, Arctic fox, John Drake, Corin dump truck Jordan Turner, Lee horn barn ha born. Rather. Jason. Caduceus. Robert. Handle. Kim. Baron, Paula. Esposito, Bob. Czapski, Ron. Thorson. Arthur. Lotz. Hall, DSM. Reuben. McCarthy, Daniel. Donaldson, Frank. Stewart, time Lord, IRA, Will Hamilton, Ian Abdullah, and Jeff McDonald. Thank you. I cannot thank all of you enough. 

Fraser Cain [00:32:42] But we’re sure going to try. 

Pamela Gay [00:32:43] Yeah. Thank you. We are. 

Fraser Cain [00:32:44] Thanks, everyone, and we’ll see you next week. 

Pamela Gay [00:32:46] Buh 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.