Ep. 693 – Mission Roll Call Part 2: Looking Outward from Earth

Last week, we brought you up to speed on the spacecraft which are helping to study Earth from above. Many of our missions are in Earth orbit but looking outward to study the Universe. Today, we’ll talk about the missions close to home, helping us understand our place in the cosmos.


(This is an automatically generated transcript)

Fraser Cain [00:01:49] Astronomy Cast Episode 693 Mission Roll Call. Part two Looking outward from Earth. Welcome to Astronomy Cast for weekly facts based journey through the cosmos, where we help you understand not only what we know, but how we know what we know. I’m Fraser Cain and 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, Pam. How you doing? 

Pamela Gay [00:02:12] I am alive, I want to say anything. Anyone ever told you about how easy it is to get a gall bladder removed? May have been their personal experience, but may not be your personal experience. Yeah, I am here to say it was much worse than they anticipated, but I am here, and this is. This is my first time in my studio since the eating of the gallbladder occurred. 

Fraser Cain [00:02:38] Well, I’m sorry you had to go through that, but then you hear that was a straight up, full on Canadian story. It really was. And I am glad that you’re recovering because we didn’t do a show last week. And, and now we are, which is, you know, back and back on schedule and, so here’s to a quick recovery and maybe you find out you never really needed that gallbladder. 

Pamela Gay [00:03:03] Yeah. This is this is what I’m hoping. 

Fraser Cain [00:03:06] Yeah, exactly. All right, well, last week we brought you up to speed on the spacecraft, which are helping to study Earth from above. But many of our missions in are in Earth orbit. But looking outward to study the universe today. We’ll talk about the missions close to home, helping us understand our place in the cosmos. We were about one third of the way through last week’s episode, and I realized that we had made a horrible, horrible mistake. 

Pamela Gay [00:03:32] It’s true, it’s true. We thought we’d discuss everything vaguely orbiting the Earth in 30 minutes. And we ran. 

Fraser Cain [00:03:40] Yeah, yeah. And, you know, pretty quickly into it, I was like, wait a minute, we are doomed. This is not going to work. So we had to break this up. And so I think sort of the logical place was to look at the spacecraft that are looking downward and then compare and contrast this to the ones that are looking outward. So I mean, but also I think this lets us cast a bit of a wide net. So where do we sort of make our definition of this year. 

Pamela Gay [00:04:05] So I’m thinking that we stick to the things that are orbiting Earth or are in a earth-sun Lagrange point, looking at scientific things that aren’t Earth science. 

Fraser Cain [00:04:22] Okay, that sounds great. So then let’s stay close with, I guess, orbiting Earth directly. And, and I think I want to start with what would be a sort of a surprising type of object, which is a space station. 

Pamela Gay [00:04:39] Yes, yes. The the International Space Station seems to have, like, finally risen to the challenge of being a science platform in the past ten years. Like they started building this sucker in the 90s, and for years and years and years, it existed as basically a very stinky place for people to go live for long periods of time and do peacekeeping activities, including talking to Girl Scouts and Boy Scouts. And it’s good to inspire the youth. But. I wanted more science and now we are getting more science there. There are high energy detectors on board that are doing a lot of really cool research. 

Fraser Cain [00:05:24] So what are the instruments on board? Space station. 

Pamela Gay [00:05:27] So my my favorite of the instruments on board the International Space Station is nicer. This is the neutron star interior composition explorer. And it’s essentially trying to, from Earth orbit, detect the kinds of particle reactions that are capable of telling us what is inside distant objects. And that idea is sort of like magic. When you’re a small child and realize that you can measure the temperature inside your oven with, with something that you just pointed the oven. You expect there to be some sort of touching involved to get a composition. And and it turns out that using X-ray photon detectors and other ways of looking at our high energy universe, we know that these high energy particles can only be generated in certain kinds of physical conditions. And that tells us what is inside these stars. And it’s just basically a rock that’s hanging out on the ISS. And that’s the other cool thing about a lot of these detectors is they’re just in racks, just hanging out on the International Space Station fine with all the vibrations and everything else going on. 

Fraser Cain [00:06:51] Yeah, yeah. And the fact that there’s, like, this gadget on the International Space Station that is watching neutron stars and helping map the surfaces of them is just mind bending to me. Yet there it is. And that’s just one example. So I guess, do we want to go through this by. Were you thinking wavelength? Orbit. How did you want to break this down? 

Pamela Gay [00:07:15] Well, so I think it’s interesting to point out that certain orbits attract certain kinds of spacecraft, ie. So for instance, we have in low-Earth orbit the International Space Station. And when we’re figuring out what to put on the International Space Station, we want things that aren’t going to be susceptible to vibrations because astronauts move, things can undock. And so we see things like nicer. We see things like the Alpha magnetic spectrometer that is doing other particle physics experiments. We see things that that are not sensitive to resolution. And X-rays are one of those things that we’re not going to get high resolution with anytime soon. And the reason we can stick these things in low-Earth orbit is because we’re not that worried about noise from the earthshine. So we see Chandra going into an orbit that comes in close, goes out far away. It comes in close, goes out far away. We have HST, Fermi. Even Tess isn’t in all of that high in orbit. And and so these different spacecraft are out there making observations. Nearby, so we don’t have a lot of latency waiting for information. Go back and forth, and there is this vague hope of being able to do things like grab HST and bring it back and stick it in the Smithsonian. That would be great. 

Fraser Cain [00:08:56] So I just did a rough estimate, and there’s about 35 space telescopes in orbit that. 

Pamela Gay [00:09:06] Where did they all come from? When did they all come from? Like I’m looking at my notes and I do not have I have like a dozen here. But I have to admit I’m biased towards the key ones. 

Fraser Cain [00:09:19] Like. Yeah, well that’s fine. I mean, I mean, the point being, there’s just there’s so many, and so that’s why I was sort of thinking we can talk about some sort of like some key wavelengths that are really making a difference because like, there’s maybe like there’s like five just gamma ray telescopes. Right. 

Pamela Gay [00:09:40] And we only really ever talk about, like, three of them. 

Fraser Cain [00:09:45] Yeah. 

Pamela Gay [00:09:45] Yeah, yeah. Swift Compton Compton still gets remembered. And XMM-Newton I believe does gamma rays as well. 

Fraser Cain [00:09:53] Yeah, but we’re not work. Oh, I think it’s only x ray. But we’re not talking about stuff that’s not. Active anymore, right? Because if you want to talk to me. 

Pamela Gay [00:10:03] I know, I know. 

Fraser Cain [00:10:05] That Compton went down 23 years ago. So if you want to talk about something, it still does not act like if you are not active, then it’s more like 100 space telescopes. 

Pamela Gay [00:10:14] Yeah, let’s not do that. 

Fraser Cain [00:10:16] Like I don’t how many episodes you want to do, but we, you know, we can. I tried to break it up. I don’t think I broke it up enough. 

Pamela Gay [00:10:25] Yeah, but. Yeah. No, that that that’s true. So so let’s let’s. 

Fraser Cain [00:10:29] So pick a wavelength. 

Pamela Gay [00:10:31] All right. Optical. Okay, let’s just start there. 

Fraser Cain [00:10:36] Right. Okay. Obviously we got Hubble, then. 

Pamela Gay [00:10:39] We have Hubble, and then we have Gaia, which is is, I think, my favorite telescope out there. 

Fraser Cain [00:10:46] Same. 

Pamela Gay [00:10:48] So, so Gaia is hanging out. It’s one of the suite of telescopes that’s orbiting at L2, which is this gravitational sweet spot balanced with the Earth in the sun where things are out, basically out of the way of all of the light pollution of the Earth. Hanging out, orbiting at the same rate around the sun that we are, but with less interference. It’s always good to have less interference. Yeah. Gaia has this amazing optical train. We did an entire episode on Gaia. Go! Go back. Watch it. They have the capacity to capture light from an object and essentially switch it from instrument to instrument to instrument as the system rotates, to measure positions, to measure colors, to measure spectra. And this allows them to get at the three dimensional motion of objects. And and it’s just breathtaking what it’s capable of doing. 

Fraser Cain [00:11:51] Yeah. I mean, it’s mapped 1.8 billion stars, has found tens of thousands of interesting exotic objects. It’s found planets. It’s just helped in, in astronomy, in in so many ways. 

Pamela Gay [00:12:08] And it has shown us the structure of our galaxy in details we didn’t have. 

Fraser Cain [00:12:15] Yeah. In fact, there’s like a new, article that came a new paper that came out just last week saying that they were able to measure the capillary and cliff for the Milky Way using Gaia data and calculate the mass of the Milky Way in one of the most accurate measurements ever done. Thanks to Guy. He just like you, measure how fast stars are orbiting around the center of the Milky Way and use that to map out the total mass of the Milky Way. Yeah. Yeah. I mean, it’s sort of a running meme on my channel that that I will mention guy, in every single episode. I will mention Gaia and Vera Rubin in every single episode, pretty much. 

Pamela Gay [00:12:54] I like that, I like that. I especially like the fact that it’s unclear if you’re mentioning the human or the telescope, and they’re both worth mentioning on a regular basis. 

Fraser Cain [00:13:05] Yeah. Or the nature or the concept of an integrated nature system. Gaia. Anyway, we so you talk about visible, but another, like, really powerful telescope that’s invisible. Are the planet hunters or another group? 

Pamela Gay [00:13:21] Yeah. 

Fraser Cain [00:13:21] That’s right. You’ve got good Tess and Cheops. 

Pamela Gay [00:13:24] Yes. Yeah. And and I am so glad that Tess outlived what it was expected to do. Tess, we’ve talked about this before. There’s going to be a lot of telling you. There is an entire episode about what I’m going to highlight. That’s going to happen in this episode. So Tess was originally designed to go up in concert with Jay Aust, and it would spot transits in the process of occurring, with the plan being that he would then go and observe those transits, get a spectra, and it was going to basically be the side kick that is hustlin up the important new planets for Jay Aust to observe. And for several years, Tess was up there without hustling up planets with not a lot of other things to observe them because we just didn’t have anything else was sufficient resolution in the correct wavelengths. And finally, in its extended mission, it is able to start doing what it was designed to do. And it’s it’s a sweet little spacecraft that is finding smaller planets than we’ve been able to find before. 

Fraser Cain [00:14:42] Yeah. I mean, it went and just found whatever 700 ish confirmed planet this point with. More than 1000 candidates on top of that. So, you know, I definitely wasn’t twiddling my thumbs waiting for t. I got to work right away. Yeah, and finding planets where you want to go next? 

Pamela Gay [00:15:02] I we might as well mention infrared since we’ve heard aj t. So infrared is a wavelength that was done fairly well by HST early in its lifespan. Sadly, HST ran out of coolant, so it wasn’t able to go as far into the longer wavelengths. It still has more capacity to do infrared than anything on the surface of our planet has. So we are grateful for what it’s been able to do. Going up and filling in longer is the they’re considering turning it back on Spitzer Space Telescope, which is in a trailing orbit. Right. So it’s orbit is around the sun, and it’s moving further and further away, which will mean it eventually is moving closer and closer and closer. So it’s just a slightly different orbit. But then, of course, we have that, that new bad boy, which is again hanging out at the Lagrange point. It and Gaia are out there with many friends. 

Fraser Cain [00:16:07] Yeah. New friend Euclid, which is also an infrared telescope. 

Pamela Gay [00:16:11] Exactly. I have not seen enough science papers for Euclid to make it into my brain yet. So I’m going to ask you to summarize. Euclid. 

Fraser Cain [00:16:19] Sure. Yeah. Well, the I mean, Euclid mission has two wavelengths on board. It has a visible wavelength and an infrared wavelength. And so its job is to do two things. It’s going to use spectroscopy to measure the chemical characteristics of the galaxies, and then it’s going to use the visible instruments so they can measure the size and shape of the galaxies and look for gravitational lensing. So really it’s it’s sort of in the same realm as the Nancy Grace Roman Telescope, which is coming up. And so its job is to help astronomers build the most accurate three dimensional map of the universe that’s ever been done, and by doing so, help illuminate dark matter and dark energy. So. 

Pamela Gay [00:17:01] I don’t think it’s designed specifically to eliminate dark matter. Illuminate. 

Fraser Cain [00:17:07] Illuminate was the word that I asked. 

Pamela Gay [00:17:09] Misspeak. 

Fraser Cain [00:17:10] Illuminate I would say maybe misheard. 

Pamela Gay [00:17:15] It’s your Canadian accent. 

Fraser Cain [00:17:16] My hilarious Canadian accent. But but I actually was like, you know, we don’t have a lot of time, but there was sort of like a bit of a panic with Euclid because it couldn’t find its guide stars. Oh, and so they were having some navigational issues with the telescope. And then just this week they were able to refind all of it. They had to do a bunch of software patches. It found old sky stars, and now it’s able to start doing its observations. But, the first pictures they sent home in sort of first light from Euclid. And it’s beautiful. I mean, it’s a great telescope. So, all right, let’s move to another wavelength. Yeah, I love the we like there’s Hubble, obviously. And then we moved on. There’s James Webb. You know, it’s doing great. Moving on. This is how much time we have. All right, let’s pick another wavelength. 

Pamela Gay [00:18:00] So so let’s let’s go to high energy. And the reason I just said high energies, because I’m thinking of Swift, which is a fabulous little telescope that refused to be confined to just one wavelength of light. 

Fraser Cain [00:18:15] So what a swift do. 

Pamela Gay [00:18:16] So so Swift is is designed. Per its name to swiftly get on target with new gamma ray bursts and figure out exactly where they are in the sky by going from the wide angle gamma ray detector to a smaller, x ray field of view and ultimately get people on Earth a go. Look here with your telescope and hopefully let’s identify the optical after glows of everything that goes burst in the night. This was not an acronym. It was just named Swift. 

Fraser Cain [00:18:53] Right? Because it moves quickly. 

Pamela Gay [00:18:56] It’s it’s straightforward. 

Fraser Cain [00:18:58] And so like also included in high energy, we should definitely look at x rays. 

Pamela Gay [00:19:03] So here we have, the Chandra X-ray Observatory. And Chandra is, is sort of like the old standby that’s just out there doing its job rigorously doing its job. Still doing its job. Yeah. 

Fraser Cain [00:19:19] 24 years later. Yeah. Still doing its job. 

Pamela Gay [00:19:22] Yeah. And and there are, like, no concrete plans to replace it with something. It’s it’s just out there and it’s what we’ve got and is what we’re going to have. And so you better like it. And luckily we seem to like it. It’s still doing remarkable science. Just last week, they were starting to, put together new combinations, that allow us to see how supernova evolve over time by combining the visible light that we’re used to looking at with the different wavelengths of x ray that show us where shockwaves are interacting with, material around where the supernova exploded. This is this is the kind of stuff it does. It identifies high energy interactions ranging from gas super heating in the cause, a galaxy clusters to dense stars doing their pulsar thing. They’re neutron star thing to these shockwaves. Super gas. It’s it’s just out there chugging along, continuing to do its thing. 

Fraser Cain [00:20:32] And like at almost the exact same time that NASA launched Chandra, the Europeans launch the XMM-Newton telescope, which is another X-ray telescope, and it is also just continuing to go along. And it’s it’s so funny because so many of the stories that we cover, you get like astronomers using Chandra and Newton, XMM-Newton and have discovered blah, blah, blah, like they use both of those telescopes to make these observations. And so often you’ll see credit to both instruments. And they’re just like a partnership that just goes on and on and on. It is it’s I wonder if it’s something about it’s weird, but I wonder if it’s something about the wavelength or something that that the x ray telescopes are long lasting because there are other ones as well as new star. 

Pamela Gay [00:21:22] Yeah. 

Fraser Cain [00:21:23] There’s, I mean, obviously we talked about nicer and then there’s like a new Japanese one just launched. 

Pamela Gay [00:21:32] And the thing about the x ray satellites is you clearly don’t need any coolant and is is long as the gyroscopes keep working. And I guess there’s just something magical about the the systems that they use. The Chandra servos are like, I shall keep pointing this telescope for ever. Don’t fight it. Enjoy it. 

Fraser Cain [00:21:58] All right. One thing that we don’t see a lot of is radio waves. 

Pamela Gay [00:22:05] That’s because there’s absolutely no reason to put a radio telescope in space, unless you’re partnering it with the ones on the ground. 

Fraser Cain [00:22:15] Okay. So, like, if we wanted to extend the size of the event Horizon telescope, then it would make sense to put. Yeah, more radio telescopes in space. 

Pamela Gay [00:22:25] That that is other than radio pollution that we have caused for ourselves, that’s really about the only reason to do it. We don’t have a lot of problems with radio waves getting blocked by the atmosphere. Radio waves are huge, and so you don’t end up with the atmosphere blurring out your images the same way you do with optical images and radio telescopes. You want to make them really big because those radio waves are big, and so you’re just better off sticking them on the planet until we figure out how to go fill a crater somewhere with a radio telescope. 

Fraser Cain [00:23:09] Yeah. So I did an interview with a with an astronomer who worked with the. The specter, which is a Russian radio telescope, and they were able to do sort of a prototype version of building a Event Horizon telescope, but from the Earth to the orbit of the Specter Telescope. And that was and that was like a really cool sort of proof of, of the technology. And so now we’re just waiting for somebody to finally launch a proper radio telescope. Like if you built a radio telescope in space and had that connect up with the Event Horizon Telescope, you could, for example, see the proton ring around a black hole, which is at the next level, which would be great. 

Pamela Gay [00:23:53] It would be great. We just haven’t been able to convince anyone that it is worth the the cost yet. 

Fraser Cain [00:24:00] So yeah, no we didn’t. We haven’t mentioned ultraviolet yet. 

Pamela Gay [00:24:06] We haven’t. 

Fraser Cain [00:24:08] Yeah. And that’s one of those instruments that you kind of want to go to space, right. 

Pamela Gay [00:24:13] Yeah. So there’s a little bit of ultraviolet capacity to the HST. The HST was really built as a generalist capable of of going from the infrared to the not extreme ultraviolet. And this is where I’m going to show my ignorance. I can’t think of a currently functional ultraviolet explorer. That’s just like knocking the papers out of the park on a regular basis. 

Fraser Cain [00:24:43] I mean, knocking papers so, so swift. No. Yeah. Swift has some. 

Pamela Gay [00:24:48] Yeah. Ultraviolet capability that it uses for pointing. 

Fraser Cain [00:24:53] Yeah yeah yeah. But like a straight up ultraviolet telescope. No, I mean the last big one was fuze was five and. 

Pamela Gay [00:25:03] Yeah. And they made that thing work longer than was rational. It was one that had cursed servos. So like between it and Chandra you have average they were using the Earth’s magnetic field essentially to try and keep that sucker pointed. But is there anything else there? 

Fraser Cain [00:25:23] No, I mean, there’s like I mean, there’s like a collection of, of small spacecraft similar to Swift that use some ultraviolet capability for part of their job. But, there’s nothing but no, there’s no big flagship ultraviolet telescope right now. 

Pamela Gay [00:25:40] That is. 

Fraser Cain [00:25:41] Beyond will be on Hubble. I mean, there’s like Hubble. Don’t forget about Hubble. 

Pamela Gay [00:25:44] I know, I know, but like, Hubble has limited capacity, just like Swift has limited capacity. I mean, luckily, ultraviolet rays are tiny, so you don’t need as big a mirror to get high resolution. But still, I can pout. 

Fraser Cain [00:26:03] Right. And then I guess, like the the last thing is other kinds of detections, like we talked about the Alpha magnetic spectrometer on the International Space Station. You know, there really isn’t a lot of particle experiments in space, right, yet. 

Pamela Gay [00:26:23] And, and, and this is where we do put things like that on the International Space Station right now, because that’s easy to swap out. We can do experiments that that literally you carry it up on a capsule, we swap out the panel, you bring something back that makes it easier to experiment with the technologies that we’re developing, particle detectors in general. I mean, if you look at the ones we have on Earth, we do things like build them in gold mines. They’re huge. And because you generally need something much larger, we don’t put stuff like that in space right now. So nicer is nicer is a nice compromise. 

Fraser Cain [00:27:09] Right. And then you’ve got I mean, there are no gravitational wave observatories in space yet. Yet, yet. 

Pamela Gay [00:27:16] I am annoyed with this. 

Fraser Cain [00:27:18] Right? There are plans. There are plans. Yeah. And there are no neutrino space telescopes, which maybe makes sense. 

Pamela Gay [00:27:26] Yeah. So yeah, that gets back to the you need a giant volume of liquid. And who wants to launch that into space? And who wants to figure out that moment of inertia to keep it stable. 

Fraser Cain [00:27:39] And space gives, you know, benefits for a neutrino telescope. It really doesn’t. You could put your your neutrino telescope behind half a layer of lead and you’d still detect neutrinos. 

Pamela Gay [00:27:50] Yeah. 

Fraser Cain [00:27:51] Yeah. So they. 

Pamela Gay [00:27:52] Might put them in gold mines. 

Fraser Cain [00:27:54] And coal mines. Yeah. Giant put them in Antarctica under enormous glaciers of ice. Yeah. Very cool. Well, I think we we were quickly able to get through a lot of the stuff. And I think, I guess, you know, when I did that rough count, you know, I would guess 30 ish probably, space telescopes currently operating today in various orbits related to the Earth shows you just how much astronomy has been done from just from Earth alone. 

Pamela Gay [00:28:28] And we completely ignored the things that are focused on looking at the sun, like SDO. So. 

Fraser Cain [00:28:35] Yeah yeah yeah. 

Pamela Gay [00:28:37] Yeah. 

Fraser Cain [00:28:38] So so so next I guess next week we will talk about more, missions that are across the solar system. Thanks, Pamela. 

Pamela Gay [00:28:47] Thank you, Fraser, and thank you to all the folks out there who are getting this show completely ad free because they are our patrons. This week I would like to thank, folks in in the we pay to have our names mispronounced tier. And. 

Fraser Cain [00:29:05] I’m gonna say that because it should say that. 

Pamela Gay [00:29:06] It should say that. 

Fraser Cain [00:29:07] Yeah, I really should. 

Pamela Gay [00:29:09] So so this week I would like to thank Jordan Young, Stephen White and Jeanette Wenk, borrow Andre Level, Andrew Lester, Brian Kegel, David Pogue, Boogie natt, Gerald Schweitzer, David buzz parsec, zero. Chell, Greg. Davis, Laura Kelson, Robert. Plasma, les. Howard, Joe. Holstein, Adam. Annis. Brown, Gordon. Davis, Alexis, Richard. Drum, Astro Sets, Felix. Goot, Kim, Baron. Wanderer and 101 William Andrews Gold, Roland Farmer, dam, Jeff Collins, Simon Parton, and Kellyanne and David Parker. Thank you all so very much. 

Fraser Cain [00:29:47] Thanks, everyone. We’ll see you next week. 

Pamela Gay [00:29:49] 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.