Full transcript below
You’ll be astounded when you listen to A/Prof Elizabeth Tasker as she takes us on an astonishingly brilliant 600million kilometre rollercoaster ride on the JAXA Hayabusa missions to collect the very first Asteroid samples and bring them back to earth for analysis, to reveal the primordial origins of our solar system.
You’ll marvel at this triumph of ingeniously designed and executed science and engineering!
Elizabeth also gives us an update on JAXA’s 2026 Mars Moons mission ~ MMX
Great science stories of discovery are essentially … great human stories.
Listen: https://soundcloud.com/astrophiz/astrophiz210elizabethtasker
FULL TRANSCRIPT:
Brendan: Welcome … and welcome to your 2025 season of the Astrophiz Podcasts.
My name is Brendan O ‘Brien, and first of all, we would like to acknowledge Australia’s first astronomers, the Aboriginal and Torres Strait Islander people, the traditional owners and custodians of the land we are on. This episode is produced on Yorta Yorta country …
… and we’d also like you to influence your local politicians to do more to mitigate climate change by moving from fossil fuels to renewable energy sources.
Each month, we produced two fabulous episodes on the first of each month. Dr. Ian AstroBlog Musgrave gives us his monthly sky guide, plus a unique astrophotography challenge and an astronomy ‘tangent’. Then, on the 15th of each month, we publish an interview with a leading astronomer, astrophysicist, space scientist, data scientist, telescope engineer, project manager, or particle physicist, and we discover their science journey and rare insights into how they think, when they think best, and how they conduct their amazing research into exactly how our universe works.
Our audio files and transcripts are available on our website at Astrophiz .com and our MP3 files can be freely streamed or downloaded to your favorite device from our SoundCloud channel, our free audible stream, YouTube podcasts and Apple podcasts.
And right now we’re zooming up to ISAS near Tokyo to speak with an amazing astrophysicist, Associate Professor Elizabeth Tasker, who has some beautiful stories for us about some seemingly impossible space missions that bought home the goods.
Let’s go!
<SFX: snippet of Morse Code>
Brendan: Hello Elizabeth.
Elizabeth: Hi Brendan.
Brendan: Today listeners we’re lucky enough to be speaking again with Associate Professor Elizabeth Tasker, an Astrophysicist and Science Communicator based at the Institute of Space and Astronautical Science, ISAS, at the Japanese Aerospace Exploration Agency, known as JAXA, close to Tokyo.
Thanks for speaking with us today Professor Tasker.
Elizabeth: Oh, thank you for having me on Brendan.
Brendan: Ah, Thanks. Look, that’s great. Now, just before we have a quick look at your work at JAXA and then focus on some incredible sample return missions, I’ll just remind listeners now that we first featured your work back in 2016 and then again in 2017. So, new listeners and early career researchers who want to have some insight into Elizabeth’s fabulous science journey can simply go to tinyurl –DOT-com / aprofelizabeth … That’s all lowercase or one word …
… because today we’ll keep our sights set on JAXA’s complex and difficult sample return missions where robotic spacecraft are sent to distant bodies in space where they land, collect surface and subsurface samples, then return them to Earth for analysis. How does that sound Elizabeth?
Elizabeth: Sounds pretty amazing to me Brendan.
Brendan: Okay I’m looking forward to hearing all these stories. Thank you. So please … now I’ve checked and since we haven’t spoken for seven years … can you believe it? Can you bring us up to date and summarize your professional roles at JAXA please?
Elizabeth: Right, yes, so I’m an astrophysicist and science communicator working at JAXA’s Institute of Space and Astronautical Science, ISAS, and as you mentioned that’s based just south of Tokyo.
My main research area is extrasolar planets, which is what we’ve chatted about in the past.
So these are planets that which orbit around other stars, but I’m also very involved in the planetary missions at JAXA, which of course involve planetary bodies that orbit our own sun.
And in particular, I’m on the outreach team for the Hayabusa2 mission and MMX mission, both of which we’re going to chat about today.
Brendan: Fantastic, that’s so cool. Okay, now we should also give a bit of background on JAXA and what it is. Now Japan has launched about a hundred missions for over 50 years now and has a enviable success record. Hayabusa translates to ‘falcon’ in English which is a formidable creature in any language. I’ve got them on my property in the country up in Northeast Victoria … but let’s jump straight in and can you tell us about the original Hayabusa mission launched back in 2003 to asteroid Itokawa and how far away was asteroid Itokawa and how did it go and what did you learn from the sample analysis?
Elizabeth: Yes, so this is a little bit before my time since I started my work at JAXA after the launch of the successor to Hayabusa 2. But the original Hayabusa mission launched on May 9th, 2003. Now unlike Hayabusa 2, this was actually a technology demonstration mission, meaning that its primary goal wasn’t science, but whether it was even possible to get to an asteroid, collect a sample and return home.
And also, JAXA were demonstrating these new ion engines for interplanetary travel. So, as a result of this, Itokawa was picked primarily based on where it was, like how easy was it to reach, given the launch date and flight capabilities of the Hayabusa spacecraft … And Itokawa and indeed, when we get to it … Ryugu … are what we call near Earth objects.
Now, of course, those have been in the news quite recently because we often hear about them when they’re about to hit the Earth or do a close pass. Now, as it turns out, fortunately, neither Itokawa nor Ryugu are considered dangerous, but they do orbit between the Earth and Mars, so they can pass quite close to the Earth. Their location is a lot closer than most asteroids, which exist in the asteroid belt, which is out past Mars.
And I think Itokawa at the time was maybe 300 million kilometers away when Hayabusa visited it. And it is a peanut -shaped asteroid, whereas Ryugu, which was visited by Hayabusa2, which I know we’re going to get to, is more of a spinning top shape, whereas Itokawa looks, yes, decidedly like a peanut.
And the mission arrived at Itokawa first core site of the asteroid in September, 2005. And then it did a touchdown to collect surface material in November that year before returning to Earth in 2010, where it dropped the sample capsule into the Australian outback. Now, this mission was very successful. However, it did not go ‘problem free’ shall we say … shortly after launch in November 2003 it was struck by one of the biggest solar flares in recorded history … And this damaged the solar cells on the spacecraft and there was also later damage to the reaction wheels and the ion engine …
So all this meant is not only did Hayabusa arrive much later back to earth than was anticipated because of this damage … no one actually knew if there’d even be a sample. They knew the spacecraft had touched down but it hadn’t gone smoothly. And so for all they knew, they were carrying an entirely empty sample capsule. And indeed, when Hayabusa itself reached Earth, the spacecraft was incredibly damaged.
I mean, it had been a real brute force effort to even get it back to Earth. And they knew that at that point, Hayabusa would not be able to continue on to any kind of extended mission. They would actually lose control of the spacecraft and it would fall disintegrating the atmosphere. And in fact the last manoeuvre they ever did with Hayabusa was to turn the spacecraft around so that its cameras could look at Earth one last time before it disintegrated. So when you see the images of the Hayabusa sample-return capsule returning to Earth, You see these as shooting stars as they get shock-heated in the atmosphere.
And for the Hayabusa1, you see actually two sets of lights. You see one for the sample return capsule coming down to Australia. And above it, you see an explosion of lights, which is a spacecraft itself disintegrating in the atmosphere.
However, when they got it down and they had this sample capsule and there was the big question, you know, is there anything inside? They opened it and it did in fact appear to be empty. However, closer inspection found there was tiny grains clinging to the inside of that sample container and they have been studied all over the world with recent research papers coming out even in the last few years.
Brendan: That is fantastic, Elizabeth. Wow! And it came back and it brought a sample back. That would have inspired the scientists there at JAXA to develop the Hayabusa2 mission out to the asteroid Ryugu, a much more difficult, ambitious mission by the sound of it … to collect both a surface and then a subsurface sample.
Now Ryugu is millions of kilometers away, which converts to quite a few light-minutes, so you can’t send commands in real time. Can you tell us how Hayabusa2 got out to Ryugu and what did it do there when it arrived? … and what about those first surface samples?
Elizabeth; Right, so Hayabusa brought back the world’s first sample from an asteroid. But as I mentioned it was primarily a technology demonstration, was this even possible? And the answer clearly was ‘Yes! Yes it is.!’
The Hayabusa2 was launched and this one had the primary aim of being science. So although it went also to one of these near Earth objects, Ryugu was picked not just because of its reachability, but also because of its scientific potential. So Ryugu is what we call a C-type asteroid or carbonaceous asteroid.
And we think that these asteroid types, and indeed this was proved to be true once we got the sample home … are very pristine … and haven’t been changed much since the very start of the solar system. And that means that we hoped that Ryugu could tell us something about how the Earth formed. It’s sort of a time capsule from when the Earth was first forming along with the rest of the planets in our solar system.
So with this goal in mind, Hayabusa2 was launched on December 3, 2014, and it arrived at Ryugu … another near-Earth object, which at the time was again, I think, about 300 million kilometers away from Earth … on June 27, 2018, that was the official arrival time when the spacecraft reached what we would call the home position, which is about 20 kilometers from the Ryugu surface.
And first thing it did was examine the asteroid. There was a sweep of on-board instruments, and so it spent some time examining the surface. Now this produced some surprises. The main one being that there was absolutely no clear area for landing. Now you might think, ‘Oh, come on, you know, it’s an asteroid, of course, it’s rocky’.
Now, you know, the team knew this, but if we compare it to Itokawa, which is also a very rocky asteroid. However, Itokawa also had some fairly smooth, plain-like areas where it was safer to land than in the heavy, bouldered regions. With Ryugu, it was boulders everywhere!
The team had been hoping for an area of, you know, maybe 50 meters, 100 meters of clear area. The best they found was a clear area of six meters. And it wasn’t that clear. So this meant the team had to … on the fly … change how they were going to do the landing to make a much more high precision landing to hit that space. Because if they didn’t, they missed and they hit a more bouldered space, the larger boulders hit the spacecraft to, you know, overturn or the solar panels … to hit the surface if the slope was too high.
And then you’d have problems rising up. Because as you mentioned, you can’t control the spacecraft going down. You have to send all these commands ahead of time. And then the spacecraft has to autonomously do this landing and collect the sample and then rise back up to a safe position.
So because of this, the team did a whole bunch of practice runs where they go low over the surface and they rise back up. And one of the problems they discovered during this, which is actually Hayabusa 2 behaving very sensibly … is that as Hayabusa 2 started the descent, but before it got to the altitude where it should have stopped, it started rising up again. The team were like, “What happened? What was the problem?” It turned out that Ryugu, being carbonaceous, is incredibly dark in colour. It was so dark that the LiDAR couldn’t get a clear reading. And so when Hayabusa 2 started to be uncertain in its altitude, it did the sensible thing. It aborted and it went back to a safe position.
Now this problem was fixable. They had to just adjust the sensitivity of the instruments and try again. But it was, you know, you have to do a lot of practice runs because you’re not going to be there on scene to be able to do any real life adjustments.
So the original plan, if I remember this correctly, was actually to do a landing at the end of 2018. But they looked at the surface and thought, ‘It’s starting to look all scary down there. We need more data.’
Now, fortunately, Hayabusa 2 was carrying two sets of landers. It was carrying one lander called Mascot, which was developed by the French and German Space Agencies. And this was a shoebox-sized laboratory to do experiments beyond the surface of the asteroid. And it was also carrying two little rovers that we call the Minerva 2-1 rovers. And these look, they look like spiny cylinders, they’re very small, they’re only about 18 centimeters across, and they were actually a technology demonstration.
Their purpose was simply to move on the surface of an asteroid, which is not nearly as trivial as you might think, because there’s so little gravity you can’t use wheels or caterpillar tracks because there’s not enough friction. So instead, these little rovers actually hop.
So they have inside them a mechanical mechanism that turns. And as it snaps back, you get a rebound force and they bounce. But both of these, the Minerva rovers and the Mascot lander were equipped with cameras. So the team deployed these first. The Minerva rovers, I think, were deployed at the end of September 2018. And Mascot was deployed at the start of October in 2018. And they landed safely on the surface and sent back more pictures.
Now, these pictures were not reassuring. It turns out that when you’re very close to the asteroid, it looks just as bad as when you’re far away. But nevertheless, it was more data and that’s always useful. And so the team in the end did the first landing on February 22nd, 2019.
And at this time, there was about 20 minute communication (lag} time to get a message to the spacecraft and back again. So the whole landing was done autonomously. And the way it works is that if you look at the Hayabusa2 spacecraft, it has what we call a sample horn, which looks like a long cylinder extending from the base of the spacecraft. And it’s this that touches the asteroid’s surface. So the spacecraft descends very slowly and prior to that, actually prior to beginning the descent, it drops something called a target marker. And this is just a reflective ball. And the point of this is because the asteroid is so dark, the target marker provides a reflective point which helps Hayabusa to judge its velocity compared to the asteroid.
Brendan: Yep.
Elizabeth; So these target markers were dropped in advance. And actually, as a fun fact, they contain the names of many people who submitted their name and message before launch. And the names were actually engraved on strips that went around the target marker.
And they’re now on asteroid Ryugu. But those names were a safety feature. The reflective target marker guided Hayabusa2 down to the surface. And then as the asteroid sample horn touches the surface, a five gram Tantalum bullet is fired down the sample horn … and the point of these little projectiles is it stirs up surface material.
So this gets broken up and it rises up the sample horn as Hayabusa2 starts to rise itself and it goes into the sample capsule. And that was the first touchdown there in February.
Brendan: That is astonishing! What beautiful science! Fantastic technology and problems solving on the run … that … that’s sensational … thank you! I felt like I was there while you were describing it ….. now hang on …. I mean who doesn’t love Tantalum bullets? But why choose Tantalum Elizabeth?
Elizabeth: The reason is that you don’t want to be confused with any material that’s on the asteroid so I think that the Tantalum bullets and indeed as we’ll talk shortly there was also a copper projectile later were specifically picked because it’s not going to be any of the minerals or compounds that you’d find naturally on the asteroid and therefore if any shreds of it are found in the sample you know exactly what it is and it doesn’t confuse the science.
Brendan: Beautiful, makes perfect sense. Okay so the first surface sample is sealed safely stored inside the capsule in Hayabusa2.
Would you like to tell us now about the collection of the second sample, the subsurface sample? How did that happen and what was different about the sampling technique for the subsurface sample?
Elizabeth: Right, so Hayabusa2 had this ability to collect multiple samples.
But they’ve just done this first sample collection. And it was really difficult. You know, they’d only found this space six meters across. And now they had that sample, everything had gone smoothly.
There was every reason to suspect the sample was safe and secure inside the sample capsule. So here’s the question, Brendan. Do you risk it all to get the second sample?
Brendan: Whoa!!
Elizabeth: The team were divided, there was not an easy answer to this question, because before, you know, if something went wrong, you lost a spacecraft, the mission was over. That’s why, as well, that Hayabusa2 spent a long time studying Ryugu with its on-board remote instruments and sending that data back to Earth, so that if something went wrong during the sample collection, you still had a huge amount of data.
But now, you have the prize, you know, got the holy grail …that sample. And if you lose the spacecraft on the second sampling and you already know that surface is incredibly dangerous, you lose both the spacecraft, the mission end, and you lose that first sample, you successfullycollected.
So the debate went on. And in the meantime, the team performed an experiment they were going to do anyway and would still be valuable even if they didn’t go for that second sample.
They dropped something called the SCI, the Small Carry-on Impactor.
Now this was a two kilogram copper plate that was dropped from the spacecraft and explosives actually shot it into the surface of the asteroid. And the purpose was not to punch Ryugu, but it was actually to expose subsurface material.
Now the reason for that is that although Ryugu doesn’t have any kind of atmosphere, so we don’t expect weathering in the sense that the Earth has weathering, the surface can still be changed by things like, you know, the sun’s radiation, micro meteorite impacts, cosmic rays, and all those things can give a surface that’s a bit different from the real material that makes the asteroid, and that confuses the science.
And indeed it was later proved that this is an issue for Ryugu because the initial data taken by the spacecraft suggested that the asteroid was quite dehydrated. Now we never expected water on Ryugu … it is too small, is too low pressure, the whole thing is a rubble pile.
Where would you even put a lake? You can’t do it.
However, what we were hoping for were minerals that contained water in their structure, because this can tell us about, for example, how habitability first came to Earth. And the initial data from the spacecraft was a bit, “Eh, maybe, maybe not.” But it turned out that actually the Ryugu sample is quite rich in hydrated minerals, but the surface layer has been dehydrated by the so-called space weathering. And this was the importance of checking out the surface sample.
Now, even if we couldn’t bring the second sample home, exposing that material and looking at it with a suite of on-board instruments would still be very valuable. So while the team were in a huge debate, “Do we, don’t we?” They actually dropped the SCI and that was dropped on April 5th in 2019.
And when it’s dropped, they were planning to create a brand new crater completely fresh and exposes subsurface material. But they knew there’d be a lot of debris thrown up. So to protect Hayabusa2, Hayabusa2 drops the SCI and then it runs. And it flees behind the asteroid until that impact has happened.
But the team obviously didn’t want to miss out on the fun. So they actually deployed a DCAM, which is a deployable camera to sit and watch what happened. And DCAM actually has this beautiful shot where you see the edge of the asteroid and you can see like material being ejected off it from that SCI impact.
It’s really cool. So once that happened, then Hayabusa2 snuck back from around the asteroid and checked out this new crater and did some images. It did look different. The albedo was a bit different from the rest of the asteroid. That’s like how much reflectance you get off the surface. And the team thought, “You know, we really want a bit of that sample.”
And in the end, the engineers said, “We can do it.” And so the mission (project) manager, Tsuda Yuichi, he said, “You know, I trusted the engineers.” He said, “They could do it. I believed them.”
And so we went in, so he’s project manager, we went in and we took that second sample. So as a result on July 11th, which is actually the day before my birthday, 2019, We went down for the second touchdown, and the spacecraft didn’t land exactly in the crater, because on a very dangerous asteroid that is like even more dangerous to land in a crater. But you could see from the images that Hayabusa 2 had gathered, where that material had been spread around the crater.
So it landed in an area where we could see the ejecta had fallen and collected that sample. And this time the accuracy I believe was less than one meter in terms of getting the exact spot for touching down safely and gathering up material.
So the team got that second sample, and this time, you know, that really was it.
So in November that year, Hatabusa2 departed Ryugu and it went on a trajectory back to Earth. And now initially it’s on a collision course because when it releases that sample capsule, that sample capsule has to be on a collision course. So it releases the capsule while it’s heading directly towards the Earth and the capsule was released on December 5th in Japan time and then Hayabusa2 performed a final manoeuvre that then swerved it out of the Earth’s path and that was because the mission actually had gone incredibly smoothly, not struck by solar flares and it actually had plenty of fuel left … and so it has gone on to an extended mission to check out another asteroid.
And meanwhile, that sample capsule landed on December 6th now in the Australian outback in the Woomera Desert and was collected by the team there.
Brendan: That is amazing! I can imagine the debating between your engineers and mission command making that “go/no go’ decision and having all of that complex engineering to come up with a solution.
That’s beautiful Elizabeth, okay. Look, so the samples, as you mentioned, were sent back, they landed. Can you tell us some of the things that JAXA does to ensure that the bugs and the dust and the bacteria from earth cannot get in and contaminate the sample capsules or the samples themselves at any stage in the mission. You’ve got to an incredible trouble to collect those samples.
What do you do to keep them in that pristine condition that they’ve had for billions of years?
Elizabeth: Right, so this is really the crux of a sample return mission. Like, why do a sample return? After all, in some ways nature does sample returns … ’cause every now and again, it lobs a meteorite at the Earth and that lands on the Earth’s surface and isn’t that basically a piece of an asteroid right there that we can pick up?
And of course it is … and we do amazing science with meteorites. But the problem with meteorites is a couple of problems. One is that journey through the Earth’s atmosphere is very tough. So it means you have a strong sample section based on the material that’s tough enough to reach the Earth’s surface.
And the second problem is that as soon as it hits the Earth’s surface, it’s contaminated by the Earth’s biology. Now, depending on the question you want to ask, it depends on how much that matters. But in the case of Hayabusa2 mission, we wanted to ask, potentially, about how habitability starts on Earth. So the last thing you need is the current habitability to infect your sample. It’s a really big deal.
So as a result, it’s absolutely imperative that this sample does not get contaminated by the Earth.
And the steps to ensure that are insanely long. It all starts even while the Hayabusa2 spacecraft is being constructed. So for example, there’s something called the ‘full course’ cleaning, which consists of disinfecting, washing and Opticide baths.
And in the Sample Horn, that’s the bit that’s actually going to touch the asteroid. It’s been constantly purged with pure nitrogen gas and kept under a positive pressure that pushes any particle that has the audacity to try and walk up on it back out again. And then even that, you’re still not sure. So any room where Hayabusa2 was being constructed adds monitors on it to do particle counts and samples all the time so that everyone has a really good idea of everything that was in that room, so that when you bring a sample back, if you’re in any doubt, we have records of every dust particle and organic and inorganic solvent that was in the room while Hayabusa2 was being constructed and we can cross compare and say ‘Yes that was there …No it was not’ … if there’s any doubt, and this even includes like taking a sample from the launch pad after launch to really make sure you know exactly what was there and to do your absolute best to ensure nothing … nothing is in that mechanism when you launch.
So it’s a huge process and actually I recently covered this for … we have a blog called Cosmos at ICES and I recently covered these procedures, and I asked our researchers, “Oh, yes, could you tell me a bit about what you did to ensure everything was pristine. And you know, I thought they would tell me about the clean rooms. But as I’ve just described, you know, the process starts so much far before we actually get to the clean room stage. Usui Tomohiro, who is the manager of our curation facility said, ‘Oh, yes, no problem, Elizabeth, I can tell you about that. I’ll start a Google doc and people can contribute.’
And I was like, really, you’re not just going to send me an email. And then I saw the Google Doc. And there was so much in it. And I was like … ‘Oh! That’s why you need the Google Doc!’ …because there’s just so many sections of care that went into this protection. And that’s just to get the spacecraft into space.
Once it comes back, it’s in the sample container. Now, this is not just the standard box. Instead, it’s got a hermetic seal on it that’s designed to keep out (contaminates) some minutes from the Earth. But even that, you don’t believe it’s going to last forever. And the team believed they had about 100 hours once that sample capsule landed back on Earth to get to that sample capsule and put it into vacuum conditions before you would start to worry that that hermetic seal had failed.
So we’re waiting for the sample capsule to come back. And we do know approximately when it’s going to enter the atmosphere, so people are there with cameras … and then you see this streak coming in for the sample capsule and from that you can work out where the samples actually landed, there was also a beacon fitted, and we were using as well marine radar to reflect off the parachute that gets deployed and so this all helped us narrow down to the exact landing spot of that sample capsule but when it hits the earth a clock starts … and there was 100 hours and that clock, before you risk that whole sample return mission being wasted.
So it’s high pressure.
So anyway, they start the search and I was actually at the Hayabusa control room at the time back in Japan, because I was I was helping with the English social media. And you know, we were just waiting. And then we get a call. It’s been sighted! We’ve got it! And then they sent the plane out and the plane lands and they gather up the sample container and you have to be a bit careful.
You want to rush, you want to grab it, hug it and run to a vacuum facility … but you have to remember that parachute deployed with pyrotechnics, and so there’s always a possibility that not everything is exploded. If for safety reasons, despite your excitement and you’re anxious to get it off earth style … you have to approach it very carefully and you’ll see if you look at some of the images from the collection Australia, you’ll see people in full protective gear approaching the capsule, and that’s why.
But there was no problem, and they collected the capsule, and the first thing they did is they brought it back to what we called a ‘quick look’ … to somebody, which was actually in Australia on site.
And at that point, they removed the gas that had actually been collected inside the sample canister. So that was actually the first gas that we’ve ever collected from deep space. And it tells you how tightly sealed that container was that we even managed to collect gas from around Ryugu!
And from there, the container is placed under vacuum conditions. And then it was airlifted to Japan while kept in vacuum conditions. And it was brought all the way back to our curation facilities at the Sagamihara campus. And I believe when that capsule entered the curation facilities and was safely stored in the glove compartment, the clock read 57 hours. The 57 hours were touched down through to curation.
Brendan: Sensational! The end of a mission was just as complex as any other part of a mission. That’s beautiful science and technology. Thank you, Elizabeth.
Elizabeth: So once of the sample is actually in our curation facilities. These are not clean in the sense of clean your room theme. The rooms themselves are what we call ISO6 which I believe the official grade for that means there has to be less than a thousand particles larger than 0.5 microns per cubic foot or something crazily small like that … and the sample itself are in these clean chambers which have been evacuated and vacuum baked before the sample goes in to remove any atmosphere component that were absorbed onto the surface.
And to go into these, you know, you have to pass through this sort of airlock area and wear protective suits, and you’re not even allowed to take in like regular pens or pencils or even regular paper.
It has to either be a tablet or this special clean room shed free paper to ensure there’s like no extra particles in the air that could possibly contaminate the sample. And then the chambers themselves, they’re either vacuum or they’re pure nitrogen, where that purity is kept, I think below one part per million or something, very, very pure, so that the scientists can work with samples so you have it at a reasonable pressure, but it’s not atmospheric air.
And then just in case that wasn’t enough, the team actually performed regular checks for organic and inorganic molecules every few months, and then I think a full micro-organism check like once or twice a year.
Brendan: That’s fantastic Elizabeth! So, is the analysis all done yet? What’s the science coming out of those samples? What have these Ryugu asteroid samples told us about our ancient solar system?
Elizabeth: And the sample analysis is still ongoing. and indeed it’s been analyzed in laboratories all around the world, and the team does actually announcements once every six months, where they ask for proposals from any team anywhere in the world who can say ‘Look I’ve got a really good idea for what we could study … could I receive a Ryugu grain for this experiment?’ … and if their proposal is accepted the grain gets sent to that laboratory for those tests.
So this will go on for a long time yet, but some of the earliest results we found, for example, you know, one of the questions was, ‘How primitive is the sample?’ You know, we said we wanted or we hoped it was from the very early solar system. So you could find out how the earth formed. What were the first ingredients that might have led to our planet becoming habitable?
An Analysis of the Ryugu sample shows this composition is very similar to that of the Sun, and that means it is incredibly primitive. It must have been forming around the time the Sun was very young, in this protoplanetary disk where the first solids were being born, and Ryugu, or perhaps more accurately its parent body that it must be a fragment of, must have come, must have been formed around this time.
So we’re talking, you know, 4 .5 billion years ago. So that’s pretty amazing. Now the type of meteorite that Ryugu matches most closely is what we call a CI Chondrite. And these are super rare. Like we have loads of meteorites that have fallen to Earth. But those are the CI type. There’s only about nine of them.
And they, of course, have suffered from contamination from the Earth. But they’re also incredibly rare and this tells you that it’s very hard for this very primitive material to make it through the Earth’s atmosphere and land on Earth, so even aside from the contamination issue, if you really want to find out about these very early days you’ve got to go into space and collect that sample.
One of the other the amazing things … I thought was anyway, as I mentioned. there’s no way you could have water on Ryugu. Well that turned out to be only partially true. It’s certainly true that Ryugu cannot support even an underground lake or source of water, but it had these hydrated minerals. So what we expected to see was evidence that Ryugu was a fragment from a larger body that billions of years ago actually would have had liquid water formed these hydrated minerals.
And then when Ryugu fragmented, we still see these hydrated minerals. and we saw all of that.
However what we also found was very tiny micro-inclusions of liquid, and when those were analyzed it was discovered the liquid contained, you know, regular water but also carbon dioxide.
Now for carbon dioxide to have got into these inclusions it means that Ryugu must have formed so far out in the solar system that carbon dioxide could freeze into an ice and then become part of this asteroid. So that tells you that Ryugu’s current position is nowhere near where it formed. And instead, there’s clearly a mechanism that brings material from the outer solar system to the inner solar system.
And that is support for one of the theories of how we think the Earth became habitable. Because the the earth in its current orbit probably formed dry. It’s too dry for there to have been much ice, which then leaves the question of ‘Where did we get our oceans?’
And one possibility is these were delivered after the earth formed through meteorites from comets and asteroids that carried a lot of ice and water and slammed into the earth.
And so the fact that we have Ryugu, obviously on a very close to earth orbit, packed with hydrated minerals, and seems to have formed from much further out, is support for this particular theory.
Brendan: That is mind boggling! So water is more common than we think. And where you’ve got water, you’ve got life. Who knows? So many questions. Look, while we’re talking about those samples that Hayabusa2 bought back from Ryugu, Some are currently on public display in Europe and you had no small hand in this. It would have been incredibly tense.
Can anyone go and view them? And well, can you tell us how you’ve put these grains in the public eye, please, Elizabeth?
Elizabeth: Yes, absolutely. So one of the problems we had was that while the Hatabus2 mission was followed by a lot of people. Once these samples went into these curation facilities, they were largely hidden.
As I’ve just described, these clean rooms have to be super clean. And that means you can’t put the samples in there on public display, only a handful of scientists ever see them.
But, you know, this is a mission that was followed by millions of people all over the world. And also, it’s about finding out how life started on Earth. So you don’t want to tuck it entirely away behind closed doors.
It really should be something that everyone can still participate in. So for this reason, our curation department reserved a few grains, not for scientific analysis, but for public outreach. And three of these grains are actually on display in Europe. One is at the London Science Museum, and two are at the Cité de l’Espace in Toulouse in France.
And I brought these grains from JAXA through to Europe. Now, in theory, this wasn’t too difficult because you see they’re outreach grains, they’re not reserved for scientific study. And that meant they can be taken through the standard airport security screening process. If you’re using them for scientific study, you don’t actually want them to go through the X-ray machine.
So it has to be handled with make work in a special, you know, that stuff to be done in the airport. That didn’t apply to me.
However, I was like going to explain that I was carrying asteroid grains. I mean, doesn’t it sound deeply unlikely? It’s like, ‘Oh, what’s that, Madam?’
‘Oh, it’s an asteroid grain that’s 4 .56 billion years old.’.
I mean, it doesn’t sound likely, does it? So I was a bit concerned … And I rolled up and I, you know, I had the right paperwork. And the first thing that happened, of course, I went to JAXA, I picked up the sample, and I picked this up from Curation. I picked this up from a researcher called Tada Toru. He very kindly took me through this, and he said, “Now, Elizabeth,” he said, “This grain is sealed in what we call an FFTC, a facility-to-positivity transfer container … and it’s actually a little cavity inside this metal cylinder that’s pure nitrogen, so we keep this sample grain still pristine and separated from the Earth’s environment.”
But he said, “This sample container can never lie on its side. We’ve got to keep it upright.” And I said, “Oh, what happens if it tilts?” And he said, “Well,” he said, “We can’t be sure because these grains are very small, so we’re not sure where their vulnerabilities are, but it’s possible that if it lands on its side,
there might be a weakness there and the grain might disintegrate.
Let’s just take a moment to consider that. So I’ve just been given this asteroid grain. It has traveled 4 .56 billion years across the solar system. It’s been brought back by one of the most daring missions in history. It’s been kept in pristine condition with no amount of the Earth atmosphere ever touching it. And now I’m being told there is a risk that I can bust it going through Haneda Airport security.
So that was a thing … and obviously I was very nervous, so I was very carefully carrying this asteroid grain, and then I was also worried that they just wouldn’t believe what it was and all these problems that I go up and you have to put it on this (security conveyor belt) you know, you know what airports are like they have this very bumpy track that takes it through airport … It takes it through the X-ray, and I was just like sweating the entire time …
I wonder ‘Maybe I could go through like the the x-ray machine just holding the grain would that be possible?’ I was feeling very anxious about it and I was also thinking ‘No one’s gonna believe me’, so actually the first time in seven years at JAXA I wore my little JAXA pin … now this is a small rectangular metal pin and it just says JAXA across it .. but you can only have one if you’re a JAXA employee, and you mustn’t lose it because they want it back if you either leave the agency or you retire.
So as a result, I’ve never dared wear mine before because it just screams ‘I’m going to lose this all over the place!’ But in this case, I wore it and I pinned it to my shirt. My plan was maybe to walk through the human X-ray scanner myself. And if that beeped, I’d be like, ‘Oh, I’m sorry, do I have metal along the, oh, that would be my JAXA badge. … By the way, that’s an asteroid going through your airport scanner right now … And maybe you would lend legitimacy to my whole story.’
But fortunately, despite my concerns, everything went smoothly and they didn’t actually ask any questions. It slid through and it obviously didn’t look like anything suspicious, so it was given to me. And I was flying via Singapore for this particular journey. And at Singapore Airport, if anyone’s been there, you actually do have to go through security again. So despite the fact that I had boarded the plane by the first flight, I had to do this again. And this time, this time This time the scanner did ‘Beep.’
And I saw them pulling the box out and they were like, ‘Madam, can you come over here? Can you tell me what this is?’ And I was already reaching for my laptop to say, “Let me start you off with a 45 minute presentation I have at the introduction of the Hayabusa mission. And then we can move on to my five hour lecture course of Water in the Universe and maybe conclude with some of the most recent press releases from our curation team.
But before I got … I said to her, “Oh, wait a sec, he’s an asteroid.” And this lady looked at the container,
turned to her colleague and went, “Oh, it’s an asteroid.” And then just closed the container and gave it to me. – Oh, why is it? – And the container was like, “Oh, another one of these.” And I felt like saying, “Wait a minute, wait, wait, do you realize there’s actually only ever been two sample return missions in human history that have brought an asteroid back to Earth?”
There’s now instead of being three because an Osiris Rex mission has also returned. But nevertheless, two, three, very few. And I was like, ‘No, Elizabeth, this is not helping your cause.’ And she’s giving you back the container, I take it and walk away.
So fortunately, we did safely make it to Europe and those grains are on display and you are very welcome to go and look at them yourselves. You are looking at a very small fragment of our planet’s history.
Brendan: Wow! It’s just a great reminder, Elizabeth, that great science stories are also great human stories, and they’re full of emotion and excitement and doubt and debate, and wow, that’s a great story. Thank you so much. You’ve painted a beautiful picture of that Hayabusa mission and everything that’s come out of it. Beautiful science!
And the teams at JAXA, they must be ecstatic over the success of both the original and now Hayabusa2, even though the science isn’t finished, there’s still so much analysis to happen. But science does not sleep. And I doubt if anyone at JAXA gets much sleep, either at least of all you when you’re taking precious samples through airport security.
Look, we’re going to run out of time soon, but look, can you give us a skinny on the five year MMX mission that is set to launch next year in 2026?
It was first announced about 10 years ago and the sample return missions take over a decade to get to the launch stage. It’s amazing complexity and planning. Can you tell us about the MMX mission? Where are you going? What are the science goals … and how is MMX going, Elizabeth?
Elizabeth: Right, so this is the next big sample return mission. MMX stands for Martian Moons Exploration Mission, where we spell exploration with an X, of course, and as you mentioned, is due to launch in fiscal year 2026.
And its destination is not Mars, but actually the two moons of Mars, Phobos and Deimos. And the mission aims to collect a sample from Phobos and bring this back to Earth. So the mission aims to arrive in fiscal year 27 and then return to Earth in 2031.
And I should say, you know, this is a JAXA-led mission, but it is highly international. So we have instruments from NASA. We have instruments from the French Space Agency, CNES. We have a little rover called IDEFIX, which honestly looks adorable, that is being built by both German and French space agencies. So this is a real international push to collect samples from Phobos.
Now no mission has successfully been sent to Phobos before. We do have images of both Phobos and Demos from the Mars orbiters, but their focus has been Mars, not the moons. So this is going to be the first dedicated Martian moon mission, which is really exciting.
And the Martian moons are a bit of a mystery. In particular, we’re not sure how they formed.
One possibility is that these are actually also asteroids. I mean they look like asteroids, they’re not big enough to be pulled into spheres, so they look a bit like lumpy potatoes, and indeed if you look at their spectra, so they’re reflected light, they look a bit like a class of asteroid called a D-class asteroid.
So they may be asteroids that were scattered in towards the inner solar system, snagged by Mars’ gravity and become moons. Now if so, they are like Hayabusa2 sort of evidence of this water movement if they contain hydrated minerals.
Suddenly this movement of materials through the solar systems, they can tell us a lot about how the terrestrial region might have become habitable.
Now the second option is they formed in the same way we believe our own moon formed during a giant impact with Mars itself. So something large came and smacked into the red planets. It scattered up debris and rather than forming one large moon, which is what happened around the Earth, this time it formed two small moons. And if that’s true, then the moons would have been really time capsules of Mars itself during a much earlier period in the planet’s history.
And this is also really interesting from the point of habitability, because we do think that once upon a time, Mars was a lot more habitable than it is now. Now whether Mars ever supported life, we don’t know, but we do think it had a thicker atmosphere and possibly even liquid water.
So if we can gather a fragment of what Mars used to be like at the time, that could tell us a lot about this period of history.
Brendan: Sensational! That’s beautiful, Elizabeth. Now, Bon Voyage, MMX, it’s heading out there soon, and for listeners that would like to know more about this Musk Free Mars Moons mission. That’s got a nice ring to it. Everyone can tune in to this next JAXA mission. See the people, see their research, see what they’re trying to understand about our universe.
It’s all at www-DOT-MMX-DOT-JAXA-DOT-jp … For the Japanese or the English translation, it looks amazing. Now, are you going to attend the launch, Elizabeth?
Elizabeth: I really hope I will. I’ve never actually attended a JAXA launch in person yet at Tanegashima, but hopefully MMX will be the first.
Brendan: Okay, well look, I’ve been sitting here with this huge smile on my face and just loving the science, loving a complexity, you’re a brilliant storyteller. Thank you Elizabeth. Now just before we go, is there anything else that we should watch out for in the near future? What are you keeping your eye on, at JAXA … or elsewhere?
Elizabeth: Well my main focus for the next year is definitely going to be MMX, but we will also be launching ‘Destiny Plus’, which is also going to be very exciting in the next few years. That’s going to be a flyby of asteroid Phaethon, which we think might be the origin of the Geminids meteor showers.
So it’s an asteroid, but it seems to also be a little bit active, a bit like a comet, and produce a lot of dust. So that will be a really exciting mission.
And of course, Hayabusa2 is now Hayabusa2#, where # ‘Sharp’ stands for ‘Small Hazardous Asteroid Reconnaissance Probe.’
And it’s actually a mission now focused on planetary defense. So it’s going to visit two more asteroids. It’s going to attempt a flyby of asteroid Torifune, which was previously known as ‘2001 CC21’ in 2026.
And then a rendezvous of asteroid 1998 KY26 as late as 2031.
Brendan: There’s so many things to keep our eye on. Thank you, Elizabeth. Well, thank you so much, Professor Elizabeth Tasker. On behalf of all of our listeners and especially from me, I’ve got the best seat in the house. It’s been really exciting to be speaking with you again. Thank you. I’ve really enjoyed following your career and these amazing JAXA missions.
Good luck with your next adventures and all your future travels.
And as a post script, listeners and early career researchers should know that Elizabeth is also an active exoplanet researcher who uses AI very creatively and is an established science author.
Her popular science book, ‘The Planet Factory’, is out in hardback and paperback and her edited textbook, ‘Planetary Diversity, Rocky Planet Processes and their observational signatures’, is also widely available.
Now, her innovative work on the ‘Future of Meetings’ project. She’s also involved in the development and application of online spaces, which we’re just starting to learn about now, including utilizing virtual reality for connecting people around the world.
We don’t have to fly internationally all the time, unless we’re carrying sample returns to show people all over the world.
May your career and your work at JAXA continue to be out of this world.
Thank you so much, Elizabeth Tasker.
Elizabeth: Thank you very much, Brendan. Bye now,
Brendan: Bye.
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Brendan: Oh! And remember, Astrophiz is free, no ads and unsponsored. But we always recommend that you check out Dr Ian Musgrave’s AstroBlogger website to find out what’s up in the night sky.
So we’ll see you in two weeks when we bring you Ian’s fabulous April sky guide.
Keep looking up.
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