Rosetta and Comet 67P, with Natalie Starkey - StarTalk All-Stars

On 9/30/16, the Rosetta spacecraft will purposefully join its Philae lander and crash into Comet 67P. Before then, StarTalk All-Stars host Natalie Starkey, co-host Chuck Nice and Rosetta Mission Project Scientist Matt Taylor review what we’ve learned.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Speaker 00

  This is StarTalk.

• 0:08Natalie Starkey?

  Welcome to StarTalk. I am Dr. Natalie Starkey and this is StarTalk All-Stars. Today, I am going to be your All-Star host and joining me as a co-host, I have comedian Chuck Nice.

• 0:20Chuck Nice?

  Hey Natalie. Well, Natalie.

• 0:22Natalie Starkey?

  Natalie.

• 0:23Chuck Nice?

  Natalie.

• 0:23Natalie Starkey?

  Nice to see you.

• 0:24Chuck Nice?

  Good to see you too.

• 0:25Natalie Starkey?

  Thank you for coming in.

• 0:26Chuck Nice?

  Always a pleasure.

• 0:27Natalie Starkey?

  So today, the plan is to field some fan questions about our topic today and, you know, the cosmic queries.

• 0:35Chuck Nice?

  Yes.

• 0:36Natalie Starkey?

  We're going to be looking at the topic of the Rosetta Mission.

• 0:39Chuck Nice?

  Yes.

• 0:40Natalie Starkey?

  Really exciting.

• 0:41Chuck Nice?

  It very much is an exciting mission.

• 0:42Natalie Starkey?

  Very close to my heart.

• 0:44Chuck Nice?

  I'm sure it is.

• 0:45Natalie Starkey?

  Because it's kind of what I've been doing for my research the last few years. And so, I'm excited to talk about Rosetta, very excited. And I'm also more excited to introduce our guest today, joining us via Skype, and it is Dr. Matt Taylor.

• 0:59Chuck Nice?

  Dr. Matt Taylor.

• 1:00Natalie Starkey?

  Yes, welcome Matt.

• 1:03Speaker 03

  Thank you for having me.

• 1:04Natalie Starkey?

  That's all right. Now, Matt, you are the project scientist for the European Space Agency Rosetta Mission. This is quite an exciting title. I wish I had your job, but you are really, really busy, so I don't envy you for the amount of travel and talks you're currently doing. But it's so good to have you here.

• 1:23Speaker 03

  It's my pleasure. It's my pleasure. It is a bit hectic at the moment, surely.

• 1:27Natalie Starkey?

  So, explain to us, there's a lot going on, right? So we've had, the Rosetta Mission launched, I mean, over 10 years ago now, right? And it's been traveling to this comet. It was traveling to a comet for all of this time. It had to catch up with this comet, get onto the same orbit, which is no small matter in itself.

• 1:43Chuck Nice?

  Right.

• 1:43Natalie Starkey?

  And then, in 2014, it actually caught up with the comet, went into orbit around it. First time ever we've done this.

• 1:50Chuck Nice?

  Yes.

• 1:50Natalie Starkey?

  And then, not only that, a couple of months later, landed as spacecraft on a comet, which was just the best thing ever. And, you know, first time we've ever done this. It was successful, a soft landing. There was a little bit of a bumpy ride until it came to rest, but, you know, it's done science. It did its first science sequence as planned. And since then, the little lander, little filet lander as it's called.

• 2:14Chuck Nice?

  Filet, that's correct.

• 2:14Natalie Starkey?

  Is asleep. It's gone to sleep.

• 2:16Chuck Nice?

  It's gone to sleep.

• 2:17Natalie Starkey?

  Matt, what's happened to it?

• 2:18Chuck Nice?

  Is that the scientist's way of saying that it's now on a farm with your grandmother? What do you mean when you say it's gone to sleep? What's happening? Don't you guys try to tell me something?

• 2:29Speaker 03

  The problem with it, it's like Schrodinger's lander. We can't really tell.

• 2:33Chuck Nice?

  Ah, I got you.

• 2:37Speaker 03

  Up to the comet and kick it to see if it's still alive. We just, it's highly unlikely to be able to function anymore at the moment due to power limitations, due to the fact that it's moving away from the sun.

• 2:49Chuck Nice?

  Right.

• 2:50Speaker 03

  But, yeah, as Natalie said, we carried out the first science sequence, we carried out the main part of the science. It was, it did what it was supposed to do, which was to go into hibernation. And it's just because it did this extra little leap across the comet that it was put into a situation or a location where it took a bit longer to come out of hibernation than originally planned.

• 3:14Natalie Starkey?

  I think you guys are just being cheeky though, because you were like, we want to land on a comet, but hey, wait a minute, we're gonna land three times, not once, you know? We're gonna just do it all in one go.

• 3:24Speaker 03

  Funny enough, the original, one of the original lander proposals, I think this is by Helmut Rosenbauer, the kind of main father of the lander mission itself, was to have a comet hopper that was jumping around that would go to one place and then go somewhere else. And it was as if that ethos was somehow impregnated into the lander that it wasn't happy enough to be in one place, it wanted to go somewhere else.

• 3:44Natalie Starkey?

  It knew, it was like, I like that proposal, let's do that, I'm gonna do it anyway. But it's kind of crazy because, you know, comets have like so little gravity, these things are relatively small compared to, you know, one of the planets. So it's just really lucky that it didn't, on one of these bounces.

• 4:00Chuck Nice?

  Just bounce completely off and just go, right? It would, because that could have been a scenario where it bounced off and it would have been lost forever at that point, right?

• 4:08Natalie Starkey?

  Exactly. There'd be no way of getting, it had no power itself, the lander, so it couldn't have got itself back.

• 4:13Chuck Nice?

  It couldn't have gone back.

• 4:14Natalie Starkey?

  Yeah, so that, that would have been a bad.

• 4:16Speaker 03

  It clipped one of the kind of clips or whatever you want to call some of the features on the surface of the comet, and I think without that. It had lost a little bit more momentum and without that little clip that it made, it may have had a little bit too much momentum on one of the bounces and ended up going over the edge and that was it, it would have been lost. So luck was there.

• 4:35Natalie Starkey?

  We were lucky, we got it, we got some science which I'd love to discuss if we've got time today, but you know, it's still there, but it woke up right, the lander did wake up again in, was it July last year or something?

• 4:46Speaker 03

  Yeah, it was June-July time period, but we never got a full accurate signal lock with it, there was some issues, we never really got in talking terms with it properly.

• 4:56Natalie Starkey?

  Right.

• 4:57Speaker 03

  But it's really, it's important to know, I have to know that this isn't the only part of the mission, this gets forgotten, that the Rosetta mission is more than the sixty hours of data taken that we had with Philae, that we were, and the majority of the science is being done by the orbiter and remains being done by the orbiter.

• 5:14Natalie Starkey?

  Says the physicist, I have to point out, because all the physics experiments are on the orbiter.

• 5:19Chuck Nice?

  Okay.

• 5:19Natalie Starkey?

  I'm a geologist, so I'm like, right, I want to be on the comet.

• 5:21Chuck Nice?

  You want to be on the comet and pulling up samples and getting something back and

• 5:25Natalie Starkey?

  He is exactly right, the orbiter is still functioning and.

• 5:28Chuck Nice?

  All right, so Matt, with respect to the orbiter, what kind of data are you looking to receive and as it orbits this comet on its journey, is it just primarily looking at the comet or is it surveying the, you know, what's around the comet and where the comet is going? Are both of those things happening or one of those things or what?

• 5:52Speaker 03

  It's doing both, Rosetta itself, the key aspect was that unlike any other mission we'd done before to a comet, we were going to stay with the comet. So as Natalie said before, we rendezvous and we got in the same orbit as the comet and we've been doing that for over two years now. So we got in step with the comet and we've seen how the comet has evolved in time. As it gets closer to the sun, it was becoming more and more active, throwing more material off. We've been monitoring the comet and we've been observing the comet, both the nucleus and the outer atmosphere and how that actually, in addition, how that interacts with the outer atmosphere of the sun as well. So the whole, you know, the whole nine yards, that's what we've been looking at. We've really been looking, the The whole thing about the Rosetta mission is to study this comet as in depth as possible.

• 6:37Speaker 03

  And with the lander, we get the ground truth of these measurements. But with the orbiter, we get the global view and we match those together. That was the key aspect to this. We do the majority of the science with the orbiter. But the the lander was there, Phil, he was there to get on the ground and give us the ground truth. To really dig in and and and let scientists like Natalie, who like to, you know, dig and scrape in and sniff and taste things.

• 6:58Natalie Starkey?

  It's good.

• 6:59Speaker 03

  So she's always rolling around and playing in the mud.

• 7:03Natalie Starkey?

  But Matt, what I wanted to just mention is the end of the mission. Because it's going to be a really sad time for all of us. I imagine more so for the guys that are really heavily involved on the mission side. But the end is coming. It's this year.

• 7:17Chuck Nice?

  The end is near.

• 7:17Natalie Starkey?

  The end is very near.

• 7:19Chuck Nice?

  My goodness.

• 7:19Natalie Starkey?

  And there are some really crazy plans of how this mission is going to end. And it involves essentially crashing this orbiter that's doing all this amazing science, all these very expensive instruments on board, crashing this thing into the comet.

• 7:35Chuck Nice?

  OK, now, that sounds, Matt, very much like when I was a kid, I would build a giant Lego castle and then kick it down.

• 7:45Chuck Nice?

  Why, why, why is that the end of the mission? What is going on with you guys?

• 7:50Speaker 03

  I'm like, you know, I've always wanted to break stuff, really expensive things. No, the the problem we have is the comet is moving away through Keplerian motion. It's moving away from the sun. Now, the spacecraft is orbiting around or or is in the same orbit. That's moving away from the sun as well, losing the capability of generating power. So we'll get to a situation where we would have to put it into hibernation. We had to do that before because it moved so far away from the sun anyway. And because of the orbit the spacecraft is now in with the comet, it would freeze. We're also running out of fuel. We'll have no fuel left soon. And the best thing to do was to end the mission in around September, October time.

• 8:33Speaker 03

  Actually, the reason for that is we get to a time where the solar energy is reducing, but also we go into a conjunction with the sun. So the signal that we're getting from the spacecraft. is very minimal at that time period. So we kind of thought the end of September would be a good time to close the mission off. Now, we could have just switched the mission off or do something more extravagant. And the more extravagant thing has been to control, ha- ha- carry out a controlled impact with a comet.

• 8:58Natalie Starkey?

  A controlled impact, sorry, not a crash.

• 9:00Chuck Nice?

  Yes, exactly. You know, that's what I tried to tell my insurance company about my last controlled impact with another car.

• 9:10Natalie Starkey?

  Um, I love this idea because it means on the way down, um, the instruments are still going to be on and they're going to get tons of information as they go down because this will be the closest we've ever been with the orbiter, obviously, having not crashed it into the comet yet. They've done some amazing maths to work out, sorry, math. All right, I'm in the States now, I forget math. Um, yeah, we've done some, some very clever math to work out how to orbit around this thing because it's not, kind of, it's haven't really got enough gravity for an orbiter to just orbit.

• 9:38Chuck Nice?

  It's not going to be in a gravitational tractor pull.

• 9:41Natalie Starkey?

  A little bit, but it's been in powered flight a lot of the time. So it's like, we don't want to get too close, but this comet is also active. So it's got material streaming off the surface. So you don't want to get orbited too close and be hit by dust.

• 9:53Chuck Nice?

  Right, particles coming off of it.

• 9:54Natalie Starkey?

  This is like our best chance to get close, get some really detailed images of the surface. I think, you know, one pixel, is that going to be a meter or better than that? Um, do we hope?

• 10:03Speaker 03

  I think once we get to within 10 kilometers, we, we get, we go sub meter, 50 centimeters, 10 centimeters. Uh, we're going to get very high resolution images once we get down to that level.

• 10:14Chuck Nice?

  Really?

• 10:14Natalie Starkey?

  Yeah.

• 10:15Chuck Nice?

  And, and so as you take this, uh, as you capture these images uh, and you're still in orbit around the comet as it's doing its controlled impact. Uh, are you going to be surveying all parts of the comet, like kind of going around it and taking pictures? Like, uh, you know, like a radio camera, like, is that, is, will that be the, is that the case?

• 10:41Speaker 03

  That that final, what we're calling the last words of Rosetta, is actually still being discussed, I wouldn't say discussed, it's being calculated, because although this comet is very low density and has a weak gravitational attraction, it still has gravity. So the orbiter actually is now in a bound orbit. We're about, I think it's a twenty-six by twenty-kilometer orbit. We will go closer and closer and closer, we'll get below ten kilometers. And once we get to below ten kilometers, things get very complicated because of this duck-like structure. And so we have a very weird gravitational potential once we get down to that. So we'll have to put it in a special orbit and really be careful at how we control the spacecraft

• 11:24Speaker 03

  around that time. And we will feel perturbations of that gravity. And we will be continuing to try and do as many measurements as possible once we get close by. Now, those final words, as we, you know, we're talking about the last day of Rosetta, what we do there is still being discussed, still being fine tuned. We believe it will be some kind of a resting maneuver from a close pericenter orbit. So we'll have like a, maybe an elliptic orbit that goes within about one kilometer, maybe the surface, maybe even lower, depending again on what we're doing in September. And then we'll inject towards the comet and just set ourselves up to be able to take data as close as possible. Now, the priority will be the

• 12:06Speaker 03

  imager, but also the mass spectrometer to sniff everything as close as possible. We'll have other instruments operating, but when we start getting to low power during that period, we really have to say, right, these are the priority instruments, getting those images, getting the high-resolution images, and also the high-resolution spectra from this mass spectrometer that's sniffing the gas.

• 12:26Chuck Nice?

  And that excites me. That does excite me. I love mass spectrometers. And is there, is there any anticipation as to what the comet will smell like? Because I'm hoping jasmine.

• 12:36Speaker 03

  It is far from nice. We already know how horrible this thing smells. Yeah.

• 12:44Speaker 03

  There's alcohol on it. It's like a kind of a Friday night in a bar area in any city in the US or Britain or wherever.

• 12:51Chuck Nice?

  Are you telling me this comet will smell like a drunken fart?

• 12:56Natalie Starkey?

  Yeah, pretty much. Yeah. It's probably not a good place to be.

• 13:04Chuck Nice?

  It smells like Jersey.

• 13:07Chuck Nice?

  I can say that. I lived there.

• 13:09Natalie Starkey?

  We should probably move on to some of these fan questions because we've been nattering on about this.

• 13:13Chuck Nice?

  No, that was a ton of fun and honestly that.

• 13:15Natalie Starkey?

  I want to get some questions.

• 13:17Chuck Nice?

  Yeah, we should get some questions without a doubt, but I'm so happy that we had that conversation. Because now I know that basically we spent a billion dollars to find out that a comet smells like a fart. Frankly, that was worth my tax dollars.

• 13:32Natalie Starkey?

  Good, please.

• 13:34Chuck Nice?

  All right, guys, let us go to our cosmic queries where we have taken questions from all over the internet and every different incarnation where StarTalk exists. And I am going to start off with Greg Fisher from Facebook. And Greg says this, "Are we planning any other missions to any other comets? Is there any specific interest in landing on one of the asteroids in between Mars and Jupiter or in the Oort Cloud?"

• 14:07Natalie Starkey?

  Oh, this is a great question.

• 14:09Chuck Nice?

  That is a very good question, Greg.

• 14:10Natalie Starkey?

  Good question. Thank you. This is, oh, I love this subject. There's so much to talk about, but I'll try and I'll keep it fairly short. So we're not planning any missions to comets at the moment, unfortunately. But we are planning some missions to some asteroids. Now, these are not in the asteroid belt between Mars and Jupiter because it's quite a long way to go.

• 14:28Chuck Nice?

  Right.

• 14:29Natalie Starkey?

  What we do is we wait for these asteroids to be knocked out of the asteroid belt and join us in the inner solar system. So these become near Earth asteroids.

• 14:37Chuck Nice?

  So now let me just, I'm not, and pranking on your question, Greg, but. How do we know when an asteroid is going to get knocked out of the asteroid belt?

• 14:47Natalie Starkey?

  We don't know when, but we, I don't think we can tell when anyway, but I'm probably not the right person to ask, but we know when they have been knocked out and we know, we can trace their orbits, so we can, we can observe them in space. And we have a whole list of near earth asteroids, and we have a list of those that are on potentially earth crossing orbits. These are the ones that we need to worry about, and we, we keep an eye on them. And we check, you know, that we need to just really define the orbit really carefully and work out. And gradually these fall off the list because most of them end up not, you know, as we work out a little bit more where they're going, they're not going to hit us. But there's a few that we want to go and visit with space missions because they're kind of easy to get to because they're already on a better orbit, we don't have to go as far. There's the NASA Asaurus Rex mission, which is launching this year, it should be launching this year,

• 15:32Natalie Starkey?

  and it's going to approach an asteroid called Benu in 2018, I believe. And it's going to be collecting samples to bring back to Earth, which is pretty much, probably just the second time that's happened. The Japanese had a mission called Hayabusa that did this a couple of years ago. I've worked on some of those samples, tiny little dust samples from this asteroid. But there's also the Hayabusa 2 mission, which is another Japanese one, it's already been launched, and that is going to another asteroid, near earth asteroid, and collecting some, hopefully collecting samples again. So we have a couple that we're going to. In terms of getting to the Oort Cloud, collecting samples, that's not going to happen. It's just so, so far away. Again, we need to wait for one of these comets to be knocked into the inner solar system for us to, to go to it, like we did with Rosetta and 67P.

• 16:18Natalie Starkey?

  It came to us, so it makes it a lot easier. The Oort Cloud is just an immense distance away that it would be. Yeah, we'll, we'll never get there, I don't think. Not in our lifetimes.

• 16:26Chuck Nice?

  All right. Oh, well Greg, that's a, that is a great, great question. Because this is a cool question.

• 16:33Natalie Starkey?

  Do you know what Chuck, we actually need to take a break.

• 16:35Chuck Nice?

  Okay, well then I'm not going to, I'm not going to read this then.

• 16:37Natalie Starkey?

  Can we come back? Can you save it till after the break?

• 16:39Chuck Nice?

  No, that's it. We've ruined the show.

• 16:41Natalie Starkey?

  We're ruined now.

• 16:45Natalie Starkey?

  All right, okay, so we are going to take a short break, but we'll be right back with StarTalk All Stars.

• 16:52Natalie Starkey?

  Welcome back to StarTalk All Stars. I am Natalie Starkey and I still have here with me Chuck Nice, who's gonna be asking me some more cosmic queries. And I've got Matt Taylor on hand from the European Space Agency to help answer some of the questions if I can't answer them.

• 17:09Chuck Nice?

  Absolutely. So let's, uh, let's jump right back into our cosmic queries and, uh, let's, uh, let's go to Josephina Aquero.

• 17:19Chuck Nice?

  Yes, Aquero in Waltham, Massachusetts.

• 17:22Natalie Starkey?

  Okay.

• 17:22Chuck Nice?

  And, uh, Josephina wants to know this. She says, "First of all, I'm a huge fan of Rosetta Mission and StarTalk."

• 17:31Natalie Starkey?

  Aren't we all?

• 17:32Chuck Nice?

  There you go.

• 17:32Natalie Starkey?

  Let me go.

• 17:33Chuck Nice?

  That just means you're smart, Josephina. That's all that means. "I'm a chemist by trade and I was wondering what the implications would be of a Rosetta finding

• 17:47Chuck Nice?

  that A) only left-handed amino acids were found on Comet 67P, or B) only right-handed amino acids, or C) a racemic mixture, i.e. equal amounts of both."

• 18:06Natalie Starkey?

  Hey.

• 18:06Chuck Nice?

  Now, before you and Matt go totally geek boner crazy

• 18:13Chuck Nice?

  on this question, you're gonna have to tell us what all of that means.

• 18:18Natalie Starkey?

  What it all means.

• 18:19Chuck Nice?

  Because I have no idea what Josephina is talking about, but it's an opportunity for me to learn something.

• 18:24Natalie Starkey?

  Okay, so we'll kick off with the fact that we wanna look for organic material in space. And I think this is kinda what the question's getting at. Are we looking for organic material in this comet? Well, yes, we are. There's quite a few instruments on the orbiter Lander that are looking for these features and trying to detect carbon molecules. Now, in terms of looking for anything more advanced than that, if we're talking DNA, I don't think there's anything that can look for that. But if we come back a step before we get to DNA, we've got amino acids which form from carbon molecules. And these are what we would refer to as the basic building blocks for life.

• 19:00Chuck Nice?

  Okay.

• 19:00Natalie Starkey?

  So we kinda need these to get life started, we think. Um, and our bodies contain loads of amino acids. And we found amino acids in space before. We found them in asteroids, meteorites that land on the surface as pieces of asteroids. We found lots and lots of amino acids. So we know that the building blocks are out there. Now with Rosetta... We're not looking for these specifically, but there are a couple of instruments that are trying to detect carbon compounds. Now, I'm going to pass over to Matt because he can now tell us a little bit about what some of those instruments have found. Because it's quite recent research that's just come out.

• 19:33Chuck Nice?

  Oh, we're getting breaking news here.

• 19:34Natalie Starkey?

  Yep, it is, definitely. So, yeah, Matt, there's a couple of instruments on the lander that have found some interesting stuff related to the organic material.

• 19:42Speaker 03

  Yeah, both Tolemy, so Open University instrument, and also Cossack from Germany were focusing on this specifically now. From my knowledge and now, remember, I'm a plasma physicist, so this is on the edge of my comfort zone, as it were. I know that we did find a lot of organic material. We could see that organic material. This is carbon-based material. The comet is really, really dark. It's very, very black. It reflects less than five percent of the sunlight that is input to it. So that really tells you that we have this very carbon-rich material on the surface. And as I was saying before, you know, this ground-level taste of the comet was what we needed from the fillet. And that's what it got, even with the bouncing across the surface of the comet.

• 20:27Speaker 03

  And we had samples, well, I'm trying to remember, actually, I think Cossack, if up is the top of the lander and down is the bottom of the lander. I think Cossack was pointing down and Tolemy was pointing up.

• 20:40Natalie Starkey?

  Exactly, yeah.

• 20:40Speaker 03

  And so they kind of got this fractional sample of the atmosphere in the near surface. So Cossack actually got the dust that was kicked up from the surface and really got some nice nitrogen and carbon-rich compounds. I think there were four compounds that have never been seen before. And these are associated, I think, again, on the edge of my memory, with ribose, which is a sugar, which then is, you know, again, a building block of or can be connected to amino acids and DNA. So that was seen on the bottom with Cossack, and on the top it was more of the coma material, more of the gaseous material that we were seeing in the atmosphere. And so we were able to see that and distinguish the different components from the lander.

• 21:23Natalie Starkey?

  Yeah.

• 21:23Speaker 03

  And the orbit, we have Rosina that's got this fantastic array of instruments that do mass spectrometry and can Sample material there, they've been looking at um uh more what we've we've had record or or uh instances of seeing uh different uh well, we were talking about it before, the methane etcetera. And we hope to get some uh more information on that soon. That's all I'm.

• 21:46Natalie Starkey?

  Oh, we have an insight here.

• 21:49Chuck Nice?

  Right.

• 21:50Natalie Starkey?

  This is exciting.

• 21:50Chuck Nice?

  This is cool.

• 21:51Natalie Starkey?

  But it's great.

• 21:53Speaker 03

  Related to this.

• 21:54Natalie Starkey?

  Okay, well, it's great because all the different instruments have done slightly different things. Um and actually, they don't all necessarily agree, which is quite interesting, so.

• 22:01Chuck Nice?

  Now, what what do you mean by that? Because that sounds uh that that sounds very contradictory.

• 22:05Natalie Starkey?

  Yeah.

• 22:05Chuck Nice?

  And it sounds worrisome. Uh what do you mean that they don't all particularly agree?

• 22:09Natalie Starkey?

  Well, basically, because they're measuring different things. As Matt was saying, the COSAC instrument is measuring the composition of basically the rock of of the comet.

• 22:17Chuck Nice?

  Right.

• 22:17Natalie Starkey?

  Because it's right at the surface.

• 22:18Chuck Nice?

  Right.

• 22:18Natalie Starkey?

  Whereas the Ptolemy, so it it saw nitrogen compounds and things. And then Ptolemy was measuring the gases around that, so it didn't actually measure any nitrogen. We don't really know why. Maybe the nitrogen wasn't kicked up high enough so that Ptolemy didn't get it into its its mass spectrometer. Um but it measured lots of carbon dioxide, so we know there's a lot of carbon there.

• 22:36Chuck Nice?

  Right.

• 22:36Natalie Starkey?

  They agree on some things, but then you've got Rosina, which is way outside of the comet, looking at the coma and everything outside of that. And that's, you know, obviously got different results, but I'm sure they'll be complementary. It's just you're looking at different parts. It's a.

• 22:47Chuck Nice?

  So it's not that they don't agree, it's that they're measuring different things.

• 22:51Natalie Starkey?

  Different things, yeah.

• 22:52Chuck Nice?

  And those things don't always just perfectly mesh.

• 22:55Natalie Starkey?

  No, we have to put all of these little bits of data together and build up our picture of the comet because it's an active system. You know, we've got to understand what it's doing as it goes towards the sun, how it's getting heated up and how that's affecting the different molecules on on it.

• 23:08Chuck Nice?

  Okay.

• 23:08Natalie Starkey?

  So, yeah.

• 23:09Chuck Nice?

  But the one thing that we can say, Matt, is that it's not broken. So it's not like it's measuring different things because it's not working.

• 23:16Speaker 03

  No, I I one thing that I would call is when I.

• 23:19Chuck Nice?

  What I want to know is, are you wasting my money?

• 23:23Speaker 03

  These are highly intricate instruments, but one has to recall, and I remember talking to a colleague of mine, who was an undergraduate with me when I was in Liverpool University, and he remembers mass spectrometers being as big as a room. And I think Natalie, you know, I remember talking to you at OU with these big machines.

• 23:42Natalie Starkey?

  Yeah.

• 23:42Speaker 03

  Now, you can't fly something that big in space, so you have to miniaturize the instrument. And I'm not saying the instrument, well, it has less capability. It's still a fantastic instrument, but you've miniaturized it. So it has a limited capability compared to something on Earth. So there's a limitation in what you can do. So you have to make assumptions on the observations that you're making. So the spectra have, you know, when you're looking at a mass spectrum, there are bumps and wiggles and lines everywhere that could be various different compounds that this thing's sniffing. And you have to make assumptions based on your understanding in general of what they are. So it's really, you're doing the best you can with an instrument that's been packed in from a room-sized instrument to something as big as, or smaller than a shoebox.

• 24:27Natalie Starkey?

  Yeah.

• 24:27Chuck Nice?

  Wow.

• 24:28Natalie Starkey?

  It is amazing. Because we need the instruments to be light.

• 24:31Chuck Nice?

  Right.

• 24:32Natalie Starkey?

  Because we've got to launch them into space.

• 24:33Chuck Nice?

  Exactly.

• 24:33Natalie Starkey?

  And we need them to be relatively simple, because we don't have a human to go up there and run it.

• 24:37Chuck Nice?

  Right, there's no maintenance for this.

• 24:39Natalie Starkey?

  Anything goes wrong, there's pretty much not anything you can do. You know, you pre-program sequences that it will run, and the computer programs, and it runs them. And if anything goes wrong, there's just nothing you can do about it. So these things have got to be simple, but it doesn't mean they're actually simple. You know, they're still doing very complicated science.

• 24:57Chuck Nice?

  Yeah, it's physicist simple.

• 24:59Natalie Starkey?

  Yeah. It is.

• 25:02Chuck Nice?

  Yeah, it's like, you know, you guys' simple is like most people's, I just died of a stroke thinking about it.

• 25:08Natalie Starkey?

  And they also have another version of the instrument on the ground. So the scientists, you know, have been waiting 10 years for this to get to the comet. They've actually been able to perform lots of calibration experiments on their version that they've got maybe in a chamber that's kind of like comic conditions, so it's in a vacuum and stuff. And they can actually run sequences on it to test how that instrument's going to work in space.

• 25:30Chuck Nice?

  Okay.

• 25:30Natalie Starkey?

  So that's important as well. There's a lot of work that goes into it.

• 25:33Chuck Nice?

  And so, Matt, when you're running these calibrations, do you then take that and make an adjustment to the data that you receive from space, and adjust it accordingly to the calibrations that you run here on Earth?

• 25:48Speaker 03

  Well, yeah, that's what you do. And actually, something that was done based on the Rosetta measurement. So the Rosetta, for this was for Rosina, they made measurements with their highly advanced instrument. And they were able to actually go back to data that was taken thirty years ago from the Halley mission.

• 26:05Chuck Nice?

  Wow.

• 26:06Speaker 03

  The Geoxo mission at Halley, and readdressed some of the spectra that were taken there with the instruments there, and reanalyzed them based on the measurements we have here. So in a kind of cross spacecraft mission calibration as well. So all of this data you can go across and cross compare and improve your measurements.

• 26:25Chuck Nice?

  That is fantastic. Yeah. I mean, that's really fascinating stuff. Well, Josephina, let me just tell you, that was an incredible question that you gave us. Yeah. Because, I mean, who knew that we would get all of that out of this one question? Really fascinating stuff. And I learned some things there, too. That was really great. Wow, I feel like I'm one of the Cosby kids. Look at that, I learned something too. You don't even realize. Okay, all right, I'm gonna stop that right now.

• 26:53Speaker 03

  Just to jump in there, because Josephina had asked about chirality. That was one of the measurements we wanted to do on the lander with Kotak. And that's the only instrument that could have made this measurement. And this is to look at the hand, the, it's basically the symmetry of the molecules. You can either have left-handed, or sorry, hang on, my left-handed or right-handed. And you, and again, it's this connection with the material we see in space, and how is it connected to life on Earth? And certain things on Earth have a particular chirality, and others have a different chirality. And by looking on the comet, we'd be matching and seeing if there is a match between the two. So are the amino acids on the comet left-handed or right-handed? Or are they both? And vice versa for other things,

• 27:38Speaker 03

  sugars and DNA and this kind of thing. And trying to see if there is a connection with those that we're finding on Earth. The problem is, with the lander, we weren't able to get a sample in the ovens, which was necessary to run a specific part of the Kotak instrument, which was to examine chirality. So without that, now that the lander is most likely not going to function anymore, we had not been able to carry out that measurement. So I just wanted to get back to that part of the question.

• 28:03Chuck Nice?

  Oh, nice. Yeah, it still needs doing. Still needs doing.

• 28:06Natalie Starkey?

  More missions.

• 28:07Chuck Nice?

  Well, there you go, Josephina. That's, I believe, we have thoroughly answered this question.

• 28:11Natalie Starkey?

  Yeah.

• 28:12Chuck Nice?

  From top to bottom, in and out.

• 28:14Natalie Starkey?

  We've done it.

• 28:15Chuck Nice?

  Honestly, this was, answering this question was like a cosmic proctology exam.

• 28:20Natalie Starkey?

  So, let us move on. Okay.

• 28:24Chuck Nice?

  Look at Matt laughing.

• 28:28Speaker 03

  I'm gonna have to, I'm gonna have to quote you on that.

• 28:33Chuck Nice?

  Uh, this is Sven Rosandik, or I don't know how to say his last name. I'm sorry, Sven. Rosandik.

• 28:41Natalie Starkey?

  Where's he from?

• 28:41Chuck Nice?

  Um, I don't know, but with a name like Sven, I think he's a Viking.

• 28:45Natalie Starkey?

  Yeah, I think so.

• 28:47Chuck Nice?

  So, uh, this is what Sven says. Uh, he doesn't tell us where he's from, but he's writing to us from Facebook.

• 28:54Chuck Nice?

  This is what he says. Would it be possible to land a spacecraft such as Rosetta on a comet and then stay in contact with it so that every few years it sends us more information? And so I'm gonna add on to that. Uh, with that in mind, would we be able to land on a comet? Uh, like, just say for instance, like Halley's Comet, which we know leaves our solar system, goes, and then comes back.

• 29:21Natalie Starkey?

  Yeah.

• 29:21Chuck Nice?

  Would we be able to, uh, do what Sven said? And then get readings from that comet, uh, wherever it goes, and then gather those readings when it comes back to us?

• 29:36Natalie Starkey?

  I mean, kind of, and it, there's, there's a lot to say with this answer, really. It's, it's more that, yes, you could in theory, but the problem is when comets get really far away from the Earth and the Sun, it gets really cold.

• 29:48Chuck Nice?

  Okay.

• 29:49Natalie Starkey?

  And communications take forever. So you're gonna have to put that spacecraft into hibernation, most likely, like we did with Rosetta, as it was trying to catch up with the Comet 67P. It got very far away.

• 30:00Chuck Nice?

  Right.

• 30:00Natalie Starkey?

  Um, so it, it had to go into hibernation, go to sleep for a couple of years. Um, so you, you could do that. Um, you, you need to leave a little bit on because it needs to stay warm in order for the instruments to actually kind of work. Otherwise, it's just gonna completely freeze and, and be broken. So if you could do that, bring it back in, turn it back on, not always that easy. When we had to bring Rosetta out of hibernation, that was stressful because we didn't know it was going to turn back on. It was like, you know, Matt, I mean, you can probably add something to this. I mean, I was there watching it on, you know, the internet feeds, but I was stressed, you know, and we got the signal and it took longer than we thought. And I mean, it must have been, but you were you in mission control for this?

• 30:37Speaker 03

  Yeah, I was. It was fine. It was.

• 30:39Natalie Starkey?

  It was fine. He's like, I play it down. There's been so much happening since then, but I was like.

• 30:43Chuck Nice?

  He's a kid.

• 30:43Natalie Starkey?

  That's all right.

• 30:44Chuck Nice?

  Yeah, nothing to it.

• 30:45Speaker 03

  There was a level of stress, but I mean, we, we put the, you know, the best people had designed this to happen. So, so we done the best job of getting it out of hibernation.

• 30:55Natalie Starkey?

  Yeah.

• 30:56Speaker 03

  And as you said, it had been delayed a little bit, but in the end it did come back. In fact, when you talk about stress, the one guy I remember who looked the most stressed was the person that was involved in writing the software for the hibernation exit. And he looked much, he was the most relieved person in the room.

• 31:12Natalie Starkey?

  I can imagine. I can imagine. Yeah, that would be, yeah.

• 31:16Chuck Nice?

  Because at that point, it's all on him. And you know, everybody's going to point their finger, even though they're not physically pointing a finger. They're just like, yep, Thomas, totally fucked us up.

• 31:28Natalie Starkey?

  I think I would have fainted when that happened. I would have just been like, oh my goodness.

• 31:31Chuck Nice?

  You know, it's the truth. It's just like, you know what I mean? It's like Alex Rodriguez in the bottom of the ninth and the bases are loaded and you're up to bat. And you know, when you strike out, people are just like, what a waste of $30 million. Nobody says like, it's okay. Everybody says it's okay, but you know what they're really thinking is, dude, you just wasted all of our money. And that's what, Thomas, thanks for the program. You screwed us all.

• 32:04Natalie Starkey?

  Yeah, so I can imagine that is pretty stressful. But yes, so in theory, Matt, I think, you know, we're running out a little bit of time on this segment.

• 32:13Chuck Nice?

  Are we running out?

• 32:14Natalie Starkey?

  But I think it's kind of possible, but it probably isn't the most important thing for us to be trying to do, because it's better to go to an asteroid or a comet and measure it and then get done with. Theoretically, I would love to bring samples back. That would be the best thing.

• 32:28Chuck Nice?

  So it's more important to get on that comet as it's traversing out close enough to our solar system.

• 32:35Natalie Starkey?

  Yeah.

• 32:36Chuck Nice?

  Land on it, get something off of it.

• 32:38Natalie Starkey?

  And come back.

• 32:39Chuck Nice?

  And bring a physical sample home.

• 32:40Natalie Starkey?

  Exactly, which is what we're trying to do with some of the future asteroid missions.

• 32:44Chuck Nice?

  Okay.

• 32:45Natalie Starkey?

  Okay, so we're going to wrap it up there for this section, but we're going to be right back. Some more cosmic queries when we come back with StarTalk All Stars. Welcome back to StarTalk All Stars. I'm Natalie Starkey. Still here with me is Chuck Nice and Matt Taylor from the European Space Agency.

• 33:02Chuck Nice?

  Yes.

• 33:03Natalie Starkey?

  We're going to carry on with some more cosmic queries.

• 33:05Chuck Nice?

  More cosmic queries, um, inquiries from the internet. That's my new song.

• 33:12Natalie Starkey?

  It's lovely.

• 33:13Chuck Nice?

  Yeah, my album drops on Tuesday. Thank you. All right, here's the deal. Um, I lost the question I wanted to, here it is. Graham Woolley, Graham Woolley wants to know this. Why are plutoids made of different material than comets? Their origins are both trans-Neptunian.

• 33:33Natalie Starkey?

  Oh, wow. Okay, lots of, lots of detail here.

• 33:36Chuck Nice?

  This is a guy who-

• 33:37Natalie Starkey?

  He knows what he's talking about.

• 33:38Chuck Nice?

  This is a guy who read an article in Scientific American.

• 33:39Natalie Starkey?

  I think so.

• 33:40Chuck Nice?

  I'm telling you right now, he knows his stuff. Okay.

• 33:44Natalie Starkey?

  Okay, so let's break this down a little bit. We've got the Kuiper belt or the Koipar belt, however you want to say this.

• 33:50Chuck Nice?

  Now, what's funny, I, you know, of course, doing this job here, uh, I get to talk to a lot of scientists.

• 33:56Natalie Starkey?

  Yep.

• 33:57Chuck Nice?

  And I still don't know if it's Kuiper belt or Koipar belt.

• 34:01Natalie Starkey?

  I think it's-

• 34:02Chuck Nice?

  Because I hear so many of you say it both ways.

• 34:05Natalie Starkey?

  I say Kuiper.

• 34:06Chuck Nice?

  You say Kuiper. Matt, what do you say?

• 34:08Speaker 03

  I think I oscillate, I think it's Kuiper.

• 34:12Chuck Nice?

  You're Kuiper?

• 34:13Speaker 03

  It's Dutch, I think it's Dutch origin.

• 34:15Chuck Nice?

  Okay, so yeah.

• 34:16Natalie Starkey?

  Okay.

• 34:17Chuck Nice?

  So Neil says Kuiper, you say Kuiper, Matt, you say Kuiper, but I know several physicists who say Koipar.

• 34:22Natalie Starkey?

  Yeah, I think that's what Matt said.

• 34:23Chuck Nice?

  Yeah, it's Matt Koipar too, yeah.

• 34:26Speaker 03

  I think I'm in the middle somewhere.

• 34:29Chuck Nice?

  Always the politician, Matt. Look at you, the diplomat. Right. All right, go ahead.

• 34:35Natalie Starkey?

  We have the Kuiper Belt. This is kind of way out past Neptune and the solar system. Not as far as the Oort Cloud. We also have comets, but the Kuiper Belt is important. There's a lot of comets there.

• 34:43Chuck Nice?

  Right.

• 34:43Natalie Starkey?

  It's also where kind of Pluto happens to be. So we've got objects like Pluto. Now, the difference is that we've got objects like Pluto that are around and contain a lot of ice, but seem to look a bit like a planet. That's why Pluto used to be a planet. Unfortunately, no longer.

• 35:00Chuck Nice?

  Neil killed it.

• 35:02Natalie Starkey?

  Yeah, he did. Yeah, he killed it.

• 35:04Chuck Nice?

  Thanks, Neil.

• 35:05Natalie Starkey?

  Then we have the comets, which are the remnants of the very earliest parts of the solar system. The remnants of this dust cloud that we started with.

• 35:12Chuck Nice?

  Right.

• 35:13Natalie Starkey?

  They also contain a lot of ice.

• 35:14Chuck Nice?

  Right.

• 35:14Natalie Starkey?

  Now, we still don't really understand where all of these objects came from and exactly where they formed. Now, it's thought that we've got the Kuiper Belt, which is closer in, and the Oort Cloud, which is further away. We actually think the Oort Cloud comets formed closer into the Sun than the Kuiper Belt initially. And actually, they were so close to the Sun that they kind of interacted with some of the inner planetary bodies and were kicked way out of the solar system.

• 35:39Chuck Nice?

  Okay.

• 35:40Natalie Starkey?

  So when we see them coming in to the inner solar system occasionally, and we can look at them with telescopes and even go to them with missions, we actually see their particular composition. And when we measure the ones from the Kuiper Belt, they're different. But then we've also got the plutoids, which are another kind of family of objects out there.

• 35:56Chuck Nice?

  Right.

• 35:57Natalie Starkey?

  Problem is, they're all really far away, and we don't go to them. You know, we've now, with the new horizons, of course, we have been out this far.

• 36:04Chuck Nice?

  Right.

• 36:04Natalie Starkey?

  And, well, some other missions have been that far as well, but in specifically to look at these objects. So we're still learning about them. So I kind of like can't answer the question that well. Matt, do you have anything to add? Because it's like we just, we need to just learn more about these things.

• 36:18Speaker 03

  Yeah, I think that's the thing, it's trying to constrain what you call a particular thing. And that's the thing, you start associating names to different objects. And well, as you alluding to, the Kuiper Belt and the Oort Cloud. Um, when you look at sixty seven P with Rosetta, that's a Jupiter class comet likely from the, well, we, we call it a very, a classic and a true Kuiper Belt object. We have other Jupiter class comets that we've observed that have a completely different composition. If I relate to the deuterium to hydrogen ratios, which are kind of a, a proxy for this whole where, where, where they formed with respect to the sun and the early solar system. And what we found with Rosetta and also the Hally measurements were similar to sixty seven P.

• 36:58Speaker 03

  Showing a broad range of these D to H ratios for a particular class of comets, which again, mixes up your understanding of the dynamical processes and the evolution for those particular bodies. So it's a, a bit of a difficult mix. And when you say, right, okay, Kuiper Belt, Oort Cloud, that's the comets. And then we've got the asteroid belt, but then mostly, you know, in the last ten or so years, people started talking about main belt comets as well. So this classification of these small bodies in the solar system is becoming more and more diverse. And I think they're all an intermix of everything. It's just their evolutionary processes or their evolutionary track has been very different. And by doing Rosetta, by doing New Horizons, by doing asteroid missions, we try and get a better idea

• 37:39Speaker 03

  of a one particular asteroid and how that fits into the global picture and all the massive simulations we're doing. So it's not an easy one to answer. We are learning.

• 37:49Natalie Starkey?

  Yeah, we are. And I mean, Matt mentioned the um, D to H ratios, which are really important for understanding these objects. And we can actually measure that in, kind of on the object, um, if we can get to it. Or we can measure it with telescopes. Now, you're then comparing measurements made by different kinds of instruments. But what we're looking at is essentially the composition of the water or, or ice, water, ice, or liquid water, mostly ice.

• 38:10Chuck Nice?

  Right.

• 38:11Natalie Starkey?

  Um, and we're looking at the heavy type of hydrogen, which is deuterium, in relation to the lighter type, which is hydrogen. And we're literally just looking at the, the abundance of those two things. And that tells us a lot about where we think that formed.

• 38:23Chuck Nice?

  All right, so let me ask you both this, uh, uh, based on what we just talked about there. Um, what would you rather have? A physical rock sample of an asteroid?

• 38:38Chuck Nice?

  Or a chunk of ice from a comet. So which one would you rather analyze?

• 38:47Natalie Starkey?

  Matt, you can go first. Which would you prefer?

• 38:49Speaker 03

  We've had asteroids, so has comet. We have to have a sample of a comet in a lab on Earth.

• 38:55Natalie Starkey?

  As ice, though, that's.

• 38:56Chuck Nice?

  As ice. My thing is before.

• 38:59Speaker 03

  Bring it back in a big freeze.

• 39:01Natalie Starkey?

  In a big freezer, okay.

• 39:02Chuck Nice?

  So now, now, now, let me ask you, because that's a huge, of course, we all see what happens when comets come into the solar system. They get close to the sun, they start to.

• 39:13Natalie Starkey?

  They do.

• 39:13Chuck Nice?

  And then they just kind of flame out.

• 39:15Natalie Starkey?

  Yep.

• 39:16Chuck Nice?

  So now, how? I'm sure this is a stupid question, because if we knew it, we probably would have done.

• 39:23Natalie Starkey?

  Stupid question.

• 39:24Chuck Nice?

  There are no stupid questions.

• 39:25Natalie Starkey?

  No.

• 39:26Chuck Nice?

  Totally disagree with you. When they say there are no stupid questions, I'm just like, you have not heard what I'm about to say. So, no. Is there plans or a contingency or anything to actually break off a chunk of ice and get it back here? But how would you do that with? But, you know, how do you keep something cold enough?

• 39:51Natalie Starkey?

  I know.

• 39:51Chuck Nice?

  Get it back to Earth so that it doesn't evaporate and disintegrate once it gets, you know, on the, on the journey?

• 39:57Natalie Starkey?

  It's a massive challenge, and it, but it is something that most sample-based scientists are actively thinking about and trying to work on. Actually, the first place we want to try this is on the moon, because we know we've got ice deposits at the poles of the moon. It's relatively close to us. We know we can get to the moon. We've done it lots of times. And not saying it's easy, but the challenge will be trying to collect some of these, these ices from the poles and bring them back as ice. Because you can analyze there, you can go and analyze them with an instrument on, on the moon. But ideally, we have, we want to bring stuff back because we've got the best instruments on Earth. We've got the people. We've got the instruments, and we can make the best measurements.

• 40:35Chuck Nice?

  And the best instrument of all is the tongue. And you just have a little sip of the space water.

• 40:43Natalie Starkey?

  See what it's like. Yeah. So, yeah, this is what we're trying to do. I think that's the first step. And then, yeah, if we could bring about ice from a comet, that would answer some major questions about some of the solar system formation. Now, I say that, but the problem is all the comets, as we kind of alluded to, are all different. And we, although there's going to be groups of comets that are similar, going to one comet isn't actually going to answer all the questions. You know, it's going to help us, but we need to go to lots of them, which is a bit of a problem because it's expensive.

• 41:11Chuck Nice?

  You are very greedy, Natalie.

• 41:12Natalie Starkey?

  I am greedy.

• 41:13Chuck Nice?

  Very greedy. Look at you. We haven't landed on one and you're like, oh, we gotta get to fifteen or twenty at least.

• 41:18Natalie Starkey?

  Yeah.

• 41:19Speaker 03

  Actually, just jumping in there, in 1987, when Rosetta was first thought about, that was actually a comet sample to, that was what it originated as. It was supposed to go to a comet and bring a bit back to Earth.

• 41:32Natalie Starkey?

  Yeah.

• 41:32Speaker 03

  And that was shown to be quite, I mean, it was, what we did anyway was quite extravagant. I think they were kind of going, look, look, just cut that bit because you're going crazy now. A lander, yeah, but not a lander, then come back again and then fly all the way back.

• 41:47Natalie Starkey?

  It effectively makes it like two missions, so effectively doubles the cost because not only do you have to land, you've got to then launch again and get off the, fairly easy on a comet because there's not much gravity.

• 41:57Chuck Nice?

  However, the very encouraging and positive thing about this is, we're halfway there.

• 42:02Natalie Starkey?

  We are.

• 42:03Chuck Nice?

  We got the first half of the mission done, thanks to Matt and his team, right?

• 42:06Speaker 03

  We had to prove with Rosetta that we could land on one in the first place. So, you know, this is the thing, when we went to the moon and Mars, we did lots of orbiters, we did lots of surveying to decide where to land. Whereas with Rosetta, we were doing all of this in one go. In 2014, when we arrived at the comet, we saw what it looked like for the first time. And then we had to land on it within six months.

• 42:26Natalie Starkey?

  And that's important to stress.

• 42:27Speaker 03

  Risk there anyway.

• 42:28Natalie Starkey?

  Yeah, that's really important to stress. We'd never seen this thing before. The moon, we've seen it. You know, it's right there. We can just look at it and we kind of know what it's, what it looks like on the surface, what it's made of. But yeah, comets, we have no idea. We've never seen it before.

• 42:40Chuck Nice?

  Fantastic. Well, Graham Woolley, that was a, Woolley was a great question, my friend. Very nice. We got.

• 42:48Speaker 03

  I'll just add one.

• 42:49Natalie Starkey?

  Go ahead.

• 42:50Speaker 03

  You know, to sound like, to try and bring this all in a little bit, that we're not, we don't know anything about because we've got so many comets. One of the key things with Rosetta is, and as you alluded to about remote observations, the thing that we can see these comets from the ground on Earth, and also Space Base and Hubble and other measurements like the Herschel Space Telescope, etc. By having Rosetta sitting there next to a comet, and when we're observing it from the ground, it's kind of like a bootstrapping, a calibration of the ground-based observations. So when we do that, cross-comparison between what we see in situ with what we see on the ground for 67P, we can then take those measurements and apply them to all the other cometary observations that we've ever made.

• 43:27Natalie Starkey?

  Yeah.

• 43:27Speaker 03

  And we'll make it future, so it's a nice calibration effect.

• 43:30Natalie Starkey?

  So it's almost...

• 43:31Speaker 03

  To then expand everything.

• 43:32Natalie Starkey?

  Almost like we've been to more comets and that.

• 43:34Chuck Nice?

  Right, exactly. So yeah, so everything that we've already observed.

• 43:37Natalie Starkey?

  Yeah.

• 43:37Chuck Nice?

  Now we can re-observe.

• 43:39Natalie Starkey?

  Exactly.

• 43:40Chuck Nice?

  Through the eyes of Rosetta and 67P.

• 43:43Natalie Starkey?

  Yeah.

• 43:44Chuck Nice?

  Fantastic. That's great stuff.

• 43:45Natalie Starkey?

  Good point, Matt, yeah.

• 43:46Chuck Nice?

  It's a great, great point, great point. All right, Graham Willie, way to go, man. That was a great question. I love it when these people really think very deeply about the questions they ask. Let's go to, okay, okay, Maria Macario.

• 44:03Natalie Starkey?

  Oh, okay.

• 44:04Chuck Nice?

  Maria Macario, who writes to us and says this from Facebook. "When Rosetta flew by the asteroids 21 Lutetia and 2867 Steins, what relevant information did it gather on them? P.S. I hope Chuck Nice doesn't mispronounce my name."

• 44:24Natalie Starkey?

  Oh.

• 44:25Chuck Nice?

  Just kidding, I'm sure he will.

• 44:27Natalie Starkey?

  Well, she didn't say how we were to pronounce it.

• 44:30Chuck Nice?

  Well, this is true.

• 44:30Natalie Starkey?

  We need phonetically.

• 44:31Chuck Nice?

  I screw up everybody's names, so, you know.

• 44:33Natalie Starkey?

  It sounded good to me.

• 44:34Chuck Nice?

  I hope so, and guess what? If I said it wrong, you should change your name to Maria Macario.

• 44:44Chuck Nice?

  So let's talk about these other two asteroids that she said on the flyby. Twenty-one Lutetia and twenty-eight sixty-seven Steins.

• 44:52Natalie Starkey?

  Yep.

• 44:53Chuck Nice?

  Were we able to get any information?

• 44:54Natalie Starkey?

  Yeah, we got loads of information. So we got loads of images of these things. I've never really seen them before. So, you know, beautiful images of asteroids up close, fairly close anyway. And I think also, Matt, am I right in saying we turned on some of the instruments just to have a little test to see that they were actually going to work eventually? And kind of sniffed, let's say we sniffed the asteroids. Is that, that's right, isn't it?

• 45:17Speaker 03

  Yeah, but I think, I think we also ran some of the dust instruments, but they proved that there wasn't really a coma around these objects. So, yeah, there were, there were null results, which are results.

• 45:26Natalie Starkey?

  Yeah. So, yeah, definitely. We got lots of information. So there we go. Yeah.

• 45:30Chuck Nice?

  All right. There you go.

• 45:31Natalie Starkey?

  They were like bonuses to the, to the puzzle because...

• 45:34Chuck Nice?

  Yeah, that was icing on the cake, right?

• 45:35Natalie Starkey?

  On the way.

• 45:36Chuck Nice?

  That was on the way. Exactly. Right. It's like, it's like, you know, it's like car sex on the way home.

• 45:43Natalie Starkey?

  Oh, my goodness.

• 45:43Chuck Nice?

  Yeah, you know.

• 45:45Natalie Starkey?

  We have time for a very short question.

• 45:48Chuck Nice?

  Oh, really?

• 45:48Natalie Starkey?

  Yeah.

• 45:49Chuck Nice?

  I love when I make a joke and you can't see it, but Matt was laughing.

• 45:52Natalie Starkey?

  And I'm just like, let's move on.

• 45:54Chuck Nice?

  It's like car sex on the way home. You're like, oh, my.

• 45:57Natalie Starkey?

  Next question.

• 45:59Chuck Nice?

  Matt is cracking the hell up. It's, I love it.

• 46:06Natalie Starkey?

  Okay, really quick.

• 46:08Chuck Nice?

  All right, let me find a quick, quick question. Quick, quick question. All right. This is Matt Eli from San Antonio, Texas, coming to us from Facebook. Why is the comet's surface fluffy?

• 46:19Natalie Starkey?

  Oh, no, I wouldn't longer. I'm going to have to make this really, really short. Okay, so the comet is essentially made of this early gas and dust from the solar nebula and ice, and it's kind of held together. So this, this real dust is like the fluff of the solar system. It's, it's not made it into a planet. So the planets kind of consolidated all this dust and made it solid like the planets. But in the comets, it didn't because it was kind of a low energy environment out in the comet formation zone. So this stuff stayed fluffy, a bit like candy floss kind of thing. So the surface of the comet is very much fluffy. As it goes via the sun, it loses... loses all its ices as it's going and it loses a lot of material. This dust kind of comes off it. It dehydrates the surface of the comet.

• 46:59Chuck Nice?

  Because it because the surface of the comet was never compressed to the point where it could be bound tightly.

• 47:06Natalie Starkey?

  Exactly. So we have a fluffy surface and it's that's I love the I love this stuff. This is what I do, but um.

• 47:12Chuck Nice?

  And the other answer, Matt, is cosmic fabric softener.

• 47:17Natalie Starkey?

  OK, and we make OK, that's interesting. OK, so we are completely out of time and I wish we'd had longer for that.

• 47:26Chuck Nice?

  Yeah, that was a lot of fun. I gotta tell you, that was.

• 47:27Natalie Starkey?

  Yeah, I think we've learned quite a lot. I have I've learned some stuff as well. It's good.

• 47:30Chuck Nice?

  Yeah, I'm sure it was super cool to have Matt here because I gotta tell you, having somebody who was actually a part of the mission.

• 47:36Natalie Starkey?

  Yeah.

• 47:37Chuck Nice?

  I mean, I really learned a lot. This was fantastic.

• 47:39Natalie Starkey?

  We are we're very lucky to have him, but thank you so much, Matt. Um, you've been fantastic as always, and I love your shirt, so that's cool. Didn't mention that. Um, but that's all we have time for. So, well, thanks, thanks for joining us.

• 47:53Chuck Nice?

  Thanks.

• 47:54Natalie Starkey?

  Had good fun. So that's all we have time for today. I want to thank Matt Taylor from ESA who's joined us and Chuck Nice. And that was StarTalk All Stars. I am Dr. Natalie Starkey.