The Supermassive Podcast - Sample return - what could possibly go wrong?

Episode Date: February 28, 2025

This time Dr Becky Smethurst and Izzie Clarke discover why it’s touch and go when it comes to returning asteroid samples to Earth and hear how we’ve been exchanging spit with Mars since the dawn of the Solar System.  The team is joined by Dr Sara Russell, a meteorite researcher at the Natural History Museum in London, and Dr Albert Haldemann, Mars Chief Engineer for the European Space Agency.  As ever, Dr Robert Massey is with us to answer your questions and look ahead to the next month in the night sky.  Keep you questions coming…you can email [e-mail] or find us on instagram, @SupermassivePod. The Supermassive Podcast is a Boffin Media production. The producers are Izzie Clarke and Richard Hollingham. Hosted on Acast. See acast.com/privacy for more information.

Is she on your desk? Yeah, she's on my desk. Helpful. I mean, good soundproofing. Yeah, sure. Yeah, if she just stays there, that'll be perfect. No, she jumps straight up again. Anyway.

Okay, hold on a sec. Okay, whenever you're ready. Earth and Mars have, dare I say it, been sharing spit for billions of years. So that should influence our perception of the risk. It's kind of like an all-in-one package of stuff that can perhaps help life to start. Where's Bruce Willis when you need me? Hello and welcome to the Supermassive podcast from the Royal Astronomical Society. With me, science journalist Izzy Clark and astrophysicist Dr Becky Smeders. Becky, everything okay over there?

You can tell the meow you can hear is my cat who's not happy that I'm not playing with her. Anyway, enough about cats. This month it's all about sample returns. We're traveling all over the place from asteroids and comets to the moon and Mars. We've got a lot to cram into one little show though so we'll see how we get on. Yeah, we'll try our best. We'll see what happens. Dr Robert Massey, the deputy director of the Royal Astronomical Society is here too. Robert, why are sample return missions important? Yeah, most people think about space and astronomy together and I think that's completely fair. I think of astronomy as the oldest form of space exploration and one of the oldest sciences too. and I think of astronomy as the oldest form of space exploration and one of the oldest sciences too. Most of the time we have to make maximum use of this little bit of light or other signal we're

getting from some incredibly distant object, like distant stars, galaxies and obviously black holes, but in the solar system we can do that in situ sampling, we can send spacecraft to planets, moons and asteroids and some of the time they can land on their surfaces and some of the time they can even bring chunks of those things back to Earth and that's much more beneficial because on a spacecraft any kind of lab even if you land on the surface like a Mars rover the instruments you have a set off to launch you obviously can't change them once the things on its way but if we have those samples in an Earth-based lab then we can do that so for example some of the Apollo samples from 50 years ago are still valuable because

the techniques have improved in the meantime. And it's better also than testing things like meteorites that are samples of other things that fall to Earth, because we've got much more control over that kind of processing because a meteorite coming in through the Earth's atmosphere, well, first of all, it's probably been in space for millions of years, so it'll have been affected by the sun's radiation and all those things. It'll be in better shape if it's come from the planetary surface or more representative of that surface than if it's traveled through space and burnt up in the Earth's atmosphere.

That's clearly a pretty violent thing to do to it. I just love the fact that we've got samples here from the Moon, very soon hopefully from Mars, from asteroids and comets. Even one that we tend to forget about is we've got a little bit of solar wind samples as well in the Genesis mission, which was almost a disaster actually. It crash landed on Earth, but they were still able to retrieve these bits of solar wind back in 2001. Yeah. And I think that was the hard thing about finding stories for this episode because I'm like, what do we talk about? There are so many different ways that we could go through this. But yeah, there's a lot to cover.

I feel like that should be the tagline of the show though, that the Genesis mission was largely considered a disaster. A disaster that it was coming back from the dead, wasn't it? It was just brilliant. It sounds like something from the Hitchhiker's Guide to the Galaxy, right? That was widely regarded as a bad idea. Anyway, cheers Robert, we'll catch it with you later for some more questions and this one's Starcasing Tips. Now sample return missions are difficult, possibly twice as difficult if not more than any other mission. Not only do they have to get to their target destination, but they also have to get back to Earth again as well. Yeah, so Osiris-REx launched in 2016 and was the first US mission to collect a sample from

an asteroid. It returned to Earth on September 24th, 2023 to drop off a capsule with material from an asteroid named Bennu, and the results are in. I spoke with Dr Sarah Russell, a meteorite researcher at the Natural History Museum in London, who is also the deputy mission sample scientist among many other roles. And she started by explaining how the aim of the mission is actually embedded in its name. OSIRIS-REx is an acronym for the main science aims and the O is the most important name that stands for origins. It was all about learning about the beginning of our solar system. And we're doing that by going to an asteroid that we think originated right at the beginning of the solar system

and can tell us about what the environment was like at that time. Visiting an asteroid that may be similar to ones that impacted the early Earth, so it could tell us what was hitting the early Earth as well, and so could tell us all these things about our own origins that was the main thing. The S and I is about spectral interpretation so that's comparing data that we can get from asteroids from Earth to data that we can get in space and data that we can get with the return sample as well. By comparing all those it will help us learn more about all the other asteroids out there as well. And

then RI was resource identification seeing if there's anything valuable it will help us learn more about all the other asteroids out there as well. And then RI was resource identification, seeing if there's anything valuable inside asteroids that we could potentially perhaps use to mine in the future. And then the final S is about security. So the target of the mission is an asteroid called Bennu. It's a near-Earth asteroid that has a very small chance of hitting the Earth in the future and we wanted to learn more about how it moved and how similar asteroids moved as well which can help us in the future assess potentially hazardous asteroids. How do you actually get to an asteroid and then collect those samples that then have to make their way back to Earth? What is that process? How does it work?

Yeah, with great difficulty. And I have so much respect for the engineers. Yeah. Yeah. The engineers on this mission who designed this are absolute geniuses. It was absolutely amazing. So first of all, Benu is really too small to have any proper gravity. So it wasn't properly in orbit around Benu. It was flying along there

so it's like sort of a red arrow but millions and millions of miles away flying around it and then the sampling itself was what's called a touch and go which means that of the seven-year mission it was just a few seconds of terror involved in actually collecting the sample. So an arm from the spacecraft went down and touched the surface of the asteroid and collected the sample. And that was actually even more terrifying than we were actually expecting

because we thought the asteroid would be like a solid surface, but actually it has almost no strength at all. It's like a ball pit and the arm of the spacecraft just went straight through. And it was only because it had some thrusters on it that it actually managed to get out at all. Oh wow. Yeah scary. And so how much is collected on a mission like that? What size sample were you able to get? Yeah so the aim of the mission was to get at least 60 grams and we nailed that we got

121 grams. So some people say it's not very much but actually it's the biggest sample return mission from beyond the moon so it's a lot to us because we analyze it sort of tiny grain by tiny grain it's actually loads. Yeah and so then so it collects this sample how does it then get back to Earth and how scary is that process for you as someone that's on the team? Yeah, that's scary, yes. There was another sample return mission called Genesis where the parachute didn't open properly and so our biggest horrible fear was that would happen on this time but it didn't, it worked like a dream. Everything was fine. So the spacecraft dropped capsule at the top of the atmosphere.

Spacecraft now has actually gone off to explore other asteroids. And how do you make sure that that sample stays protected on that return mission? What special measures have to go into making sure that your sample isn't contaminated? Yeah, so we wanted to make sure that the sample container stayed intact, which luckily it did because it didn't crash. And then it was the sample container was taken straight to the Johnson Space Center.

So it arrived there the next day and it was transferred to a glove box. I think of a glove box is in your car just like we put in the glove box. Yeah, I know it sounds like glove box in the car, but this is literally a box with like gloves on it so that you can put your hands through and deal with it. But so the sample is being kept in a nitrogen only atmosphere and that means that it never comes into contact with the air from the earth. That means it's hopefully the reactions that it will undergo will be greatly minimized. And we're at this really exciting point where you've been doing tests

on these samples and we've got some results so let's start with the process first. What are the tests that you're running on these samples and I suppose what are the samples they're just you know dust and rock and minerals to some extent. Yeah, if you imagine you grab a handful of a rocky beach, that's what you've got. So we've got a few pebbles that are a centimeter sized. It's mostly much more fine grain than that sort of millimeter size grains.

And it's mostly black, looks black. Doesn't look very interesting to be honest with you. But that's what we had to deal with. And we split up into teams. So the sample analysis team is made up of hundreds of scientists across the world and we divided into sub teams. So I was in the mineralogy team, so I was looking at what the minerals and the rocks were made of, but we also have an organics team focusing on the organic component and a physical properties team and a chemistry team. Okay, and so yeah, what are the tests that you run on this? So what we were doing in the mineralogy team, we were taking each tiny grain and we were CT scanning it, so where you might do a CT scan in a hospital

which sort of showed us what the inside structure was, and then we put it in our electron microscope to see what it looked like at a really fine scale and that also enabled us to do some chemical tests as well so we could see what elements were present and we could also do other tests as well like x-ray diffraction which tells us what the structure of the minerals inside there was. And what did you find? So what we found was that the rock was made mostly of clay minerals which is kind of what we were expecting. So when we looked at the asteroid from space, we thought we could see the presence of water.

And the best way to kind of preserve water in a rock like this is in the form of clay minerals that can absorb that into their structure. But the thing that really surprised us that we weren't expecting is that we saw this whole range of salt minerals. So these included carbonate minerals like calcium carbonate, but also sodium carbonate, phosphates. We found this very unusual sodium magnesium phosphate and we also found sodium chloride table salt and

potassium chloride. So we found this kind of whole array of minerals that we weren't really expecting because we don't really see them on meteorites and we think that's because when every meteorite comes through the Earth's atmosphere and it's exposed to the humidity of Earth and it's kind of delicate soluble salts will just disappear. And so what does that actually tell us? Because this mission is all about understanding our early solar system. So what can we glean from all of those samples and understanding those minerals? Yeah, so we were really excited to see the salts because it reminded us of a rock type on earth called evaporites and these are formed when maybe a lake becomes really hot and the water evaporates

away and leaves behind a sequence of salts. And so these are fairly well understood. They're often used for mining and that sort of thing on earth, these deposits. So we could use that to sort of say what kind of water was there before. So we think that there was alkaline, salty room temperature water that was present, not on the surface of the asteroid

because it would just immediately evaporate, but in kind of pods of water on the surface of the asteroid because it would just immediately evaporate but in kind of pods of water underneath the surface. And that was really exciting for a couple of reasons. So firstly, we think we see these kind of briny water in other places in the solar system too. There's salt deposits on Ceres that may have formed by briny water. Enceladus has got spurts of

material coming out that probably comes from a brine as well. So we think that maybe we've seen this evidence for stuff that happens actually over the solar system. So on the Earth's surface, evaporates are quite rare and unusual, but maybe they're really

common in our solar system. So they might be telling us about this universal geological process. And the other exciting thing is that brines are great places to grow organic molecules. So the organic molecules were probably quite simple at the beginning of the solar system, but after they've experienced these salts and this water, that could enable more things to grow. And while we were doing our mineralogy study, our organics colleagues were looking at what organics were there, and they found some really exciting array of organics.

They found amino acids, including 15 out of 20 of the amino acids found in life. They found all five of the nuclear bases that are used in RNA and DNA. This makes us think that maybe asteroids like Bennu in the beginning of the solar system would have rained down on the early Earth, not just Earth, Mars as well, and could have brought all of this stuff to the Earth.

So it would have brought water, would have brought all these interesting organic molecules, also phosphates that can help act as a fertilizer as well. So it's kind of like an all-in-one package of stuff that can perhaps help life to start. Thank you to Dr. Sarah Russell from the Natural History Museum in London. So we spoke a lot about the minerals of Bennu but as Sarah mentioned part of the sample mission was to understand the asteroid's movement and you know potential threat towards earth. So do we have any

results on that part of the mission yet? Yeah, there have been a few papers on that. So calculating this risk of impact that we have between Bennu and the Earth and also some sort of climate modelling has been done in case of impact as well, just so we could better understand it. So I'll start by saying that any possible but unlikely impact is way, way in the future, right? We're talking late next century, so nothing for sort of us to worry about in the near term here. But therein lies the problem with it being so far away this risk because we know Bennu's orbit to

some accuracy and we know that Earth's orbit to much higher accuracy to be fair. But then what we have to do is extrapolate those orbits way, way into the future. And so any tiny uncertainties you have now just get massively inflated as you go anywhere into the future, right? They just balloon further out you go in time, right? And so the most significant percent chance of impact is going to occur in September 2182, with a current probability impact of 0.037%, which is like a one in 2,700 chance, right? So the probability is low and it's way off, right? It's more likely the asteroid is going to be somewhere else in that region of uncertainty, right, at the time and just fly past Earth. But the chance is not zero currently. Benu is considered one of the most

hazardous objects of the known asteroids. Again it was why it was chosen for the Osiris-Rex mission as well. And so because of its size at like 500 meters wide, it's about 1600 feet. Just for some context, right? I want to give you sort of like, okay, the asteroid that killed the dinosaurs was more like 10 to 15 kilometers wide. Six to 10 miles. So we're not talking anything like that kind of size. It's a lot smaller than that. So the impact, if it did actually impact with Earth, then subsequent impact wouldn't be

as big. That's catastrophic. Yes, exactly. Like it still would be a huge area of devastation as catastrophic. Yes, exactly. Like it still would be a huge area of devastation for wherever it hit, obviously. There would be an impact on the climate. So there's been a lot of studies that have looked

at what that impact would be. In fact, there was a paper that came out just this month, February, 2025, looking at this, because obviously you're gonna throw dust up into the atmosphere that's gonna block the sun and change everything that's going on. So they found in this paper that it would be 400,000 tons of dust in the atmosphere. It would lead to a global drop in temperatures

on average of about four degrees Celsius and then a 15% drop in the amount of precipitation. And you'd obviously then get the subsequent drops in photosynthesis and like the productivity of like marine life and land life and things like that. So a little decline on everything. Yeah. So life on earth would take a bit of a beating and obviously have to adapt. And while this isn't a problem for our generation, just rest assured that, you know, scientists are still keeping an eye on this. Obviously you're going to improve our estimates of orbits. So it's being monitored, right? And I'm not losing any sleep over this, right? Because the percentage chance is very low and it's much more likely that it's going to be somewhere else and just fly past Earth quite close instead.

Okay. But what I think was really interesting about this mission is that the spacecraft has now gone off to explore another asteroid. So it's been renamed Osiris Apex. So what's next for this mission? Yeah, I mean, I love this. It's like waste not want not. NASA are very good at doing this at repurposing stuff. And, you know, they returned the sample without Osiris Rex actually coming back to Earth. It looped around Earth and just sort of jettisoned the sample

back to the atmosphere and it parachuted down. Yeah, I'm on my way. I'll chuck this back at you. You know, so it was great that they did this. So now it's heading out to an asteroid called Apophis, which is a similar size to Bennu. It's about 450 meters wide. And for those not familiar, Apophis is particularly infamous because back in December 2004, that was when initially it was discovered our uncertainties

on Apophis's orbit weren't great. They were quite big, which gave it a 2.7% chance that Apophis would impact Earth on Friday the 13th of April, 2029. I'm sure the media loved that one. Yeah, I think the reason for its infamy was probably fueled by the fact that it might have impacted on Friday the 13th. Yes, exactly. It really didn't help with the fear mongering at the time. But as I said with these things, we get more observations, our uncertainties on the orbit come down and so we know better where it's going to be in the next couple of years and

out to hundreds of years in the future as well. And so we now know that in 2029, that's not going to happen. Instead, we're just going to happen. Instead, we're just going to get a really cool close flyby of Apophis, about 30,000 kilometers. That's 10 times closer than the moon that this asteroid is going to come. It's going to be the closest that, you know, an old asteroids come to the earth ever in human recorded history. So it's going to be a really fun thing to spot in the sky rather than, you know, something to worry about. And so I think it's rather than, you know, something to worry about.

And so I think it's great that, you know, OSIRIS-REx has been redubbed to OSIRIS APEX to go and study Apophis. It's actually going to like rendezvous with it in April 2029. So just a few days after that really close approach to Earth. And it's then going to study the asteroid for about 18 months. And once again, sort of approach the surface, fire its dusters to throw up material so we can learn more about what Apophis is made of. Because, you know, we have to kind of question things like, you know, is it just certain types of asteroids that end up coming into the inner solar system? Do you know, do they have the same, you know, ingredients for life like's been detected on Bennu as announced this past month as well, you know, like amino acids and things like that, you know, or are they completely

different? You know, we just don't know because we don't have enough data samples. The more and more of these sample return missions we send, the more information we get about our solar system and maybe even clues to where we came from as well. Yeah, they're very cool. And so there were also the Japanese Hayabusa missions which collected more asteroid samples. So how were they different because they've come before a Cyrus Rex. So how were they different? Because they've come before a Cyrus Rex. So what? Yeah, how were they different from a Cyrus Rex? Yes, there's been both Hayabusa 1 and Hayabusa 2 that JAXA sent in to space to collect asteroid samples.

And they were the real trailblazers for this type of mission as well. It had never been done before Hayabusa 1. So Hayabusa 1 was the... It's just Hayabusa. I say Hayabusa 1 just differentiated from from high booster two, but it was just named high booster. It was the first, right? And it managed to collect less than a gram of material from the ever so slightly smaller asteroid. It's a cower back in 2005 and it returned that to earth in 2010. But obviously with such a small sample, it's really very hard to make any strong conclusions because you can find some things in it, but you obviously don't get the natural variation you would get from a larger sample. So Hayabusa 2 then went to the much bigger asteroid of Ryugu at the end of the 2010s that returned 5.4 grams of material back

to Earth in late 2020. So that's 0.2 ounces for our metrically challenged listeners there, just to give you an idea of how much it actually was. Again, it's a small amount, but it's better than what Hayabusa brought back, but still, you struggle to make any sort of big conclusions about that. And you compare that to a Cyrus Rex, which returned about 120 grams, about four ounces of material from Bennu, right? So it was much easier for us to answer a lot of questions. There was also multiple teams that could work on like different bits of the sample as well with different techniques and different instruments.

It could be split because every time you need to do a different test with a different instrument or different experiment that takes a bit of the sample. And so you reduce it each time. So there's more tests you can do with more of it it which is is great but it was kind of like the same questions that they were trying to answer with both missions like what were the asteroids made of what ingredients were there did the asteroids bring ingredients for life to earth did they bring water to earth what was the

concentration of these different things I saw respects had more of the sort of instruments to study the asteroid as well while it was there, just because of the fact that high-based missions had shown that this was possible beforehand, so we could, you know, pack it full of a few more instruments. So they were so key and instrumental in our understanding of asteroids. Thanks, Becky. And in a moment, we'll be talking about the Mars sample return mission. Now, we couldn't do a sample return episode or not talk about Mars, right? We've chatted in previous episodes about our pal Percy, our beloved little rover on Mars, Perseverance,

right? Officially, that's what NASA call it. And Perseverance is drilling into the Martian surface to collect samples of rock. So the next stage of the mission is to get those samples from Mars back to Earth. But what are the plans to make that happen and how are scientists protecting these samples from contamination? I spoke to Albert Haldeman, who is Mars Chief Engineer at the European Space Agency. One of the objectives of Perseverance was to collect samples in view of their then later return to Earth. And NASA and ESA have been setting up a cooperation.

There have been some delays and changes because of things we've learned as we went through the design and development process. The European contributions that we're moving forward with for sure is the Earth Return Orbiter, the first spacecraft to do a round trip to Mars from Earth. The plan now, after NASA's recent studies, is to put the NASA-developed capture containment and return system on top and the Earth Return Orbiter, ESA's ERO, will rendezvous with the samples once they reach orbit. And they will reach orbit using a using a NASA developed rocket that NASA will land on the surface and the Perseverance herself will deliver the samples that she's guarding in her belly, keeping nice and cozy but not too warm actually keeping them rather cool and cold for scientific

purposes, deliver those to the rocket to the orbiting sample container and launch back to orbit retrieval to Earth with ERO. Can we look at those possible methods of collection? What are some of those ideas to get these samples or that first leg of returning these samples back to Earth? So the first leg is that Perseverance continues the scientific collection. That's the main component of the NASA-ESA cooperation. In fact, a sample is not acquired until a particular geologic assessment of a particular rock and area outcrop is done and it's different enough

and interesting enough to add to the collection. Okay, so it's all about variety, essentially? It's about the variety, the diversity of the samples, and to maximise the diversity of the samples. Yeah. So our intention is to have 30 scientifically selected samples. Each tube, of course, contains some atmosphere on top of the rock sample, and that's something that's of interest.

So Perseverance is going to drive, complete the exploration up on the crater rim, where she is now and is acquiring samples. As of now, a total of 29 tubes have been filled. Ten were left on the crater floor at Three Forks. So there are 19 on board and there are 12 remaining tubes to be filled. We expect we will fill them and then we'll pick of those 31 on board, we'll bring back 30. Perseverance herself drives back down to wherever the sample retrieval lander or heavy lander, whichever is eventually picked by NASA to land on the surface. Perseverance herself will

deliver the samples using her own robotic arm, which currently has a drill. And the intention is to bring a different tool and swap it out, sort of like on power tools, you know, that we, many of us use in our homes, swap the drill bit for a kind of an arm bit. And so, yeah, let's talk about what Perseverance is actually doing. So how is Perseverance collecting these samples and what are the different sort of locations of the Jezero crater and geologically how are they different?

There's a drill which basically inserts the sample cutting the outside of a cylinder and then snapping off the cylinder into the sample container and each of these tubes is maybe the size of a larger classical cigar tube. Winch and Churchill size cigar tube. Impressive. But the cores themselves are a centimeter in diameter and up to eight centimeters long. The total sample content we're expecting from the 30 samples is going to be maybe as much as a half a kilo. Jezero was picked because of the very interesting geologic context that this crater was filled with water and a lake and there was flowing water moving into the crater creating

sedimentary deposits like a Delta fan and so that is history of a habitable environment, a water rich environment on the Martian surface billions of years ago that we wanted to explore. It turned out on landing that what was discovered was, happily, more volcanic rocks on the base of the crater. One of the objectives of the samples is to figure out how old the different events in Jezero are, and how old Mars is, and how old the various geologic events on Mars are.

So we had that first in the first rocks. That was exciting. Then Perseverance went to the fan and really started acquiring some of these sedimentary samples and they are varied, showing the evolution of the fan. And now Perseverance is headed up to the crater rim. The crater rim is where the deeper rocks of Mars, the Martian crust, have been lifted up because of the impact. What we're getting is exposures of deeper, older crustal rocks, more linked to the origin,

history, and formation of Mars. And so those rocks are being acquired now as samples. And once that set is completed up on the rim with some variety of the different levels that are represented by those exposures Perseverance will head back down to the crater floor and actually wait for the arrival of the sample retrieval lander. Heather So let's imagine that we understand what that collection process looks like. How concerned do we have to be about like potential contamination of any craft interfering with these samples?

So what you've asked there is sort of the lead into the whole theme of planetary protection, in fact. When you hear the word planetary protection, typically people would say, oh, it's protect the earth from things coming from the outside. And that is indeed a critical element of planetary protection. But planetary protection also means protecting the pristine nature of your target planet from contamination by Earth. So that is a big part of how Perseverance was built and how we are designing the sample retrieval lander and how we are designing the Earth return orbiter that we do not add contaminants to the samples. It is why some tubes will be sealed empty at various times

to capture the snapshot of any contaminants that were brought with Perseverance to Earth and also to characterize how much any outgassing or degradation of Perseverance to Earth and also to characterize how much any outgassing or degradation of Perseverance systems might be adding into the sample collection system over time. And it's a measure of the conditions of which the samples were collected in, I suppose, so you know like, okay, this is what the situation was when these samples were collected. And now that we have them, when we have them back on Earth, you can compare, okay, yes, has it stayed the same or is there a change there?

And then I suppose that lets you know if there has been something that sort of changed the conditions. That's right. That's exactly right, Izzy. So that's one part of it. And then part of it is also we've made very clean systems to go to Mars. The samples are inside these tubes, sealed, hermetic, and then we transfer those hermetic samples, keeping the outside of the tubes as uncontaminated as possible, into the orbiting sample container where we don't want to add any Mars contaminants to the outside of that so that we don't have to worry about them later on in the system. We have European experts outside of the European Space Agency as a review panel from various other areas

of expertise related to protecting the Earth's biosphere, medical experts and so on. But what about the other way around? How much consideration goes into bringing Mars samples back to Earth? Is there a team that has to think about, oh hang on, actually what if we find something quite unexpected, what's the safety and I guess this comes back to planetary protection in the way that we originally thought about it. What is the process and the considerations that go into bringing something from another planet back to Earth? So the considerations are first of all, what is the expectation of there being a risk?

So the process of planetary protection is codified, if you will, by the Committee for Space Research, COSPAR's Planetary Protection Panel, which has been extant since the Apollo era, since the 1960s, to take into consideration everything we know about what life can be or what kinds of chemistry can have effects on life. The earth is not unconnected to the rest of the solar system. We receive material from the rest of the solar system every day. Meteoritic material falls onto the earth. We need to recognize that in this risk assessment as well. We have meteorites on earth that came from Mars. That has been demonstrated and assessed

and is the scientific consensus based on various lines of evidence. They were rocks that were thrown off of Mars by a large impact, and then through orbital mechanics made their way to intersect the Earth's orbit and landed on Earth as entire rock samples, some of them many hundreds of grams or more. And so things in the middle could have been protected. Again, that has

happened over the entire history of the solar system. So Earth and Mars have, dare I say it, been sharing spit for billions of years. So that should influence our perception of the risk. Thank you to Albert Haldeman. This is the Supermassive podcast from the Royal Astronomical Society with me, astrophysicist Dr Becky Smethurst and science journalist Izzy Clark. This month it's all about sample return missions. So let's get on to our listener questions. We had so many so thank you so much to everyone who sent them in. Robert, Kate on email asks, what is the

Japanese mission to Mars is moon Phobos looking for? Yeah, okay. This is the so called Martian Moons Exploration or MMX mission. And it's led by JAXA, the Japanese Space Agency, as you rightly say, but also with help from the European Space Agency, NASA and Canary as well. And it's due to launch next year, so 2026, and it will go to the two Martian moons. Mars has two fairly small moons. One is called Phobos and the even smaller one is Deimos. We've had pictures of them before, but only from some distance. So things of the Viking orbiters in the 70s took pictures from a distance as they orbited Mars along with the moons. Two Russian missions

attempted to go directly to them, but they both failed. Hopefully, this is their time lucky. It's quite ambitious. It actually involves the close-up imaging you would expect, sort of a pseudo orbit around them because the gravity of these moons is not enough to hold them in orbit. Then one of the moons, Phobos, there's going to be an attempt to land a kind of rover on it. Without much of a gravitational field, there's going to be an attempt to land a kind of rover on it. Without much of a gravitational field, there's going to be a challenge in itself crawling along this surface and stopping the thing bouncing back into space. But yeah, the other aspect of it fits in very nicely with the episode, and as Becky was saying, we can't not talk about Mars and look in the interviews, it's to gather a few grams of material, maybe up to 10 grams or a bit

more of material and bring that back to Earth. And the science question is whether the moons are bits of Mars that perhaps were blasted off the planet in some giant collision, presumably with an even ridiculously large object, or whether they're captured asteroids. And if it's the first of those, then it could tell us something about how Mars formed

and help us with our evidence base for whether it was once conducive to life or not, whether it was wetter, for example. If it's the latter, then they might have water in them from elsewhere in the solar system. They might be like all these asteroids, if they aren't captured asteroids that have a bit of water in them, and that would tell us again how common that is. So that's the scientific interest in them and we have tried to look at them before. Okay, cool. And Becky, David K on Instagram wants to know, are scientists today still studying the moon samples from the Apollo missions or are they too old now?

Yeah, definitely. I know a few colleagues who are still studying Apollo samples. I was actually lucky enough to see one close up once, but I can't say where those things are. Super high security, right? They're under lock and key. And yeah, there are still experiments going on, as Robert said earlier, like it's a combination of things really. So you've got reanalysis of them with modern techniques and technology

that we didn't have back in the, you know, sixties and seventies. And then also like new questions that have only just been thought to ask, right? Because we've done further study of the moon, for example, with the lunar reconnaissance orbiter LRO, and of course that we've sent probes back to the moon as well, like with ISRO's Chandrayan missions, the Indian space research organization, so India space agency. And, you know, they've been finding all sorts of things

on the moon and, you know, raising new questions about what water on the moon, ice on the moon and things like this. And so all of a sudden people go, well, I wonder if we've seen that in the Apollo mission. So it's great that we still have, you know, so much of that still to do, you know, scientific experiments on. It really is just one of those things that is like a, I don't know, it's just so great that humanity have that.

Yeah, absolutely. For future generations. Yeah, as well. But I love that they are under, you know, lock and key spaces week, but there is a lot of care that's taken into preserving that and making sure that scientists, even as technology will continue to develop, can still keep studying them. So Robert, let's stick with the moon because Jane Lowe also asks, we already have 800 pounds, I think, of moon samples. Why do we need more?

Yeah, Jane, it does sound like a lot of material, doesn't it? And as Becky points out, securely closely guarded material, although it did get distributed around the world. Actually, some of it got given to various despots in the 70s and they got lost, but a lot of it is still secure. But this stuff only comes from a total of 11 sites. Six of those were Apollo missions and they gathered the bulk of it. The astronauts walking around the moon, they had big spaceships take them back. Then there have been Chinese, Russian, and Indian return missions as well. But imagine going to the Earth and assuming you knew everything from just standing in 11 places. It's basically impossible to sample the whole

diversity of the Earth. Even on the moon, that's true as well. The surface area is huge. It's about the same as Africa. We've basically sampled it from 11 little points. We haven't, for example, sent sample return missions to the lunar South Pole, where we know there's a lot of water ice, although India is planning one, or most of the lunar mountains. Only one spacecraft, the Chinese mission Changi 6, that collected samples from the far side, but that's the only one. So really, if you want to understand the world, those little niche touchdowns and those little tiny bits of material coming back is just not going to be enough. And that's why there's interest

in bringing more of the moon back to us or presumably when the Artemis missions get there, if those go ahead, then again, the astronauts will be gathering samples on the surface as well for exactly that reason. All right, thanks Robert. And Becky, Fez59 on Instagram has a question about the upcoming Chinese sample return mission. So that's launching this year. And they say, Tianwen2 is using a new sample capture technique. What is it and how is it different from other missions? Yeah, great question, Fez59. So previous sample return missions have used like a variety of different techniques. Right. Obviously, you've got Percy and what I'm dubbing rendezvous, so we can call him Ron. Issa, I know that you're listening.

Petition. We'll make it happen. So many times if that sample return mission is not called rendezvous, I'm going to flip some tables anyway. So Percy is obviously drilled into the surface of Mars, extracted the cause and those we picked up by rendezvous, you know, that's a much longer term mission. It's not something that's typically done for asteroids for shorter term missions like asteroid collections with the Cyrus Rex and like Hayabusa. They use what I like to call the high five technique, but was more commonly referred to as touch and go,

which is where you drop down to the asteroid and then you boop it basically, you know, you either with a charge that's detonated or just manually like right, you impact the surface to throw up a lot of debris. And then you just hoover up that debris into your sample collection. Yeah, but can I just say that mate is it almost has an ominous feel to it, like all that mission is touch and go. You're like, okay. Right, it's touch and go, it's going to work. I mean, is it going to happen?

Yeah. I guess it is a bit touch and go with how much sample you'd actually collect, right? It's a little bit out of your control in that respect. So I guess maybe it is a good name, but I still quite like the high five. I'm still imagining almost like contactless payments. You just tap this thing. Yeah, exactly. So that's one method of collecting samples, but you don't have a lot of control over it.

So what Tianwen-2 will do, it will do the same thing. It will do a touch and go sample collection as well on the asteroid Kamuawea. I don't know if that's pronounced correctly. It looks to be Hawaiian. I apologize to any Hawaiians listening if I've absolutely butchered that. But what Chiawantse will do is also try something called the anchor and attach technique,

which I guess is kind of what it says in the tin, right? It's gonna get close to the surface and then it's gonna deploy these robotic arms to drill down into the surface, which will then hold it there for a longer amount of time, right? Then you've got a lot more control about both where and what you sample as well,

and how much of it you can actually collect, right? And that's gonna be the first time that's ever gonna have been used for asteroid sample collection. So it's gonna be interesting to see what happens with Tianwen-2 when it launches later this year in May, 2025. It's gonna arrive at the asteroid around 2026 and then hopefully return it in 2027.

It's interesting because I wonder how much research they have to do into, you know, what could the surface be like, because you don't want to try and attach to something and as soon as you get a drill in there, it just like crumbles and you've got nothing to attach to. Yeah, and all you've basically done is just nudged yourself back off again by trying to drill, right? Yeah. You're like, oh wait, it's a touch and go mission after all. Yeah. So I mean, that's why it's good. They're going to get their orbit around the asteroid

for a while, actually pick out, you know, the same thing that they did to the Cirrus Rex did around Bennu as well, right? They actually will map the surface out and decide where is the best place to land because the Cir I respect with a touch and go, you are looking for loose surface. Obviously with anchor and attach technique, you're looking at a more sort of like solid stronger surface to be able to drill into. Where's Bruce Willis when you need him? Yeah. And so thank you to everyone who sent in a question. If you want to send us any more questions, please do keep them coming. You can email podcast at ras.ac.uk or find us on Instagram at supermassivepod. So Robert, let's finish with some stargazing. What can we see in the night sky this month?

Yeah, well, March is the time when the sort of spring stars get, you know, they join the ones that we can still see in the winter. So you've still got Orion in the evening and the Sirius underneath, still very, very obvious. Then you get to see more easily without staying up so late. In other words, things like Cancer, the crab, which is faint but has two beautiful star clusters, Messier's 44 and 67. The first of those is really special, Persepa. You can see it with your eye and it looks great in binoculars. Then further around, Leo, which is one of the constellations that named for the lion, does actually look a bit like a lion. You can imagine the mane

of the lion at the front of it. I think it looks a bit like a lion. I mean, imagination. Astronomers license or artistic license. Ursa Major is high overhead with a plough within that and a good signpost. The Pole Star and Arcturus, which is a really bright star in Bootes, the Herdman. So all of that is visible. And then for the planets, unfortunately, Saturn is now behind the sun, so completely invisible. But it's also a shame because it's the time on the 23rd of March when the rings are exactly edge on. And we won't see that again for nearly 15 years. So after this, they open up again, which from an aesthetic perspective is great, but that kind of novelty of seeing it without ring, this is really hard to do. We do get Mercury. That's unusual, hard to see where we are in the Northern Hemisphere,

one of its best evening sky appearances for the first two weeks in March. As ever with Mercury, quite low in the West after sunset, so get one of those apps like Stellarium and look for it just about 45 minutes after sunset. Don don't leave it too late don't start too early. Venus is really obvious so really really bright and a beautiful crescent in a telescope and it's now pretty much moving between the Earth and the Sun and that's why we've got that crescent phase and Jupiter is still there easily in Taurus and Mars is in Gemini but there are also two other highlights that I've got to mention and one is that on the 14th of March, we've got a total lunar eclipse when the moon moves into the shadow of the Earth. Now,

this takes place for us. It's an early rise of one. You need to get up about 10 past five to watch it start. Totality starts just as the moon is setting at about just before half six. That's just in the UK and Europe though, right? We have some American listeners who might catch it. That's absolutely true. If you're in North America and you can look online and see the different times. But for us, from a UK perspective, it's early start stuff. But you're right, if you're further over across the Atlantic, you get a better view. The moon might also, for us, be hard to spot as the sky is brightening. But you should still start to see that reddening that's caused by the colour of the earth's shadow as it moves into it. And then between 10am and 12 noon on the 29th of March, and again

these are UK times, you know, look them up, there's a partial solar eclipse and it's not full, not total anywhere in the world, so the moon isn't completely blocking out the sun. But if you're in, I think in Eastern Canada, about 93% of it is covered, so not bad. And the UK for us depends where you are, but in the South East it's about 93% of it is covered, so not bad. In the UK, for us, it depends where you are, but in the southeast it's about 30% of the solar surface is covered, and up in the northwest and highlands, the islands, 45%. So a decent bite. Now, the caveat on any solar eclipse is that, despite that, you know, you think to yourself you're losing all this sunlight, particularly if you're losing, say, over 90% of it, the sun remains really dangerous to look at without the right protection and ironically when you get a thin

crescent of sun left it's worse because your eye, your retina is fooled into thinking it's fainter and it opens up but unfortunately the brightness of what's left is still really damaging to your eyes. So do not try to look at it without properly certified eclipse glasses that you buy from a good supplier, a proper solar filter for the end of a telescope or binoculars, the big end, run the eyepiece end, and again bought from a reputable person. Don't buy it from some random source, it's worth spending the money on something that works. But better still, if you've never done anything like this before, then I would just say look up a local astronomical society in the UK. You've got the Federation of Astronomical Scientists, fedaistro.org.uk,

has a big list because they can offer you good advice. They might even be running events where you can see it safely because I'm pretty sure the eclipse is actually on a Saturday. It's quite well placed that if the weather's good, there might well be a few public events and a chance to see it there. Do look out for it, but please be safe. Yeah. I've already heard from a few colleagues that they're planning to do a – I wouldn, I wouldn't call it a flash mob, but just like a surprise as you walk from the station, there is some telescopes. We're looking at the sun. We're not crazy.

We promise, you know, like this kind of events that you just might run into on the street. But if you want to make sure you do find one, I'm sure there's a, we can put a resource in the description. Exactly. Yeah, we should put a link to the Federation of Astronomicals. Yeah, we'll find the fun. I'll supply the link. Thanks everyone. Well, I think that's it for this month and we'll be back next time

with actual astronauts. Yeah, we're going to have an episode on astronaut training and returning to the moon. And there'll be a bonus episode in the meantime to take on even more of your questions. Contact us if you try some astronomy at home. We'd always love to hear about it. It's at supermassivepod on Instagram, or you can email your questions to podcast.ris.ac.uk and we'll try and cover them in a future episode or a future bonus episode. The bonus episodes are definitely becoming some of my favorites, Izzy. I don't know about you, but until next time, everybody, happy stargazing.