Planetary Radio: Space Exploration, Astronomy and Science - Hayabusa2 flies by asteroid Torifune

Episode Date: September 23, 2026

JAXA's Hayabusa2 flew within 400 meters (1,300 feet) of asteroid Torifune on July 5 and confirmed that it's a contact binary, two lobes stuck together. Paul Abell, NASA's Chief Scientist for Small Body Exploration at Johnson Space Center, walks us through the findings on the asteroid, what they mean for planetary defense, and what's ahead as the spacecraft cruises toward its next target. Then Bruce Betts, chief scientist at The Planetary Society, digs into Hayabusa2's history of firing things at asteroids. Discover more at: https://www.planetary.org/planetary-radio/2026-hayabusa2-torifuneSee omnystudio.com/listener for privacy information.

Hayabusa 2 flies by asteroid Torifune, this week on planetary radio. I'm Sarah El Ahmed of the Planetary Society, with more of the human adventure across our solar system and beyond. This week, Paul Abel, NASA's chief scientist for small-body exploration at Johnson Space Center, joins us to talk about the Hayabusa 2 extended mission flyby of asteroid Torifune. We'll talk about what it revealed about this rare contact binary and what it means for planetary defense. Then, Bruce Betz, our chief scientist, is here for What's Up, where we're going to talk about the projectiles that Hayabusa 2 fired into asteroid Ryugu. If you love Planetaria Radio, I want to stay informed about the latest space discoveries,

make sure you hit that subscribe button on your favorite podcasting platform. By subscribing, you'll never miss an episode filled with new and awe-inspiring ways to know the cosmos, and our place within it. In July 26, the Japanese aerospace exploration agency, or Jax's Hayabusa 2 spacecraft, added another first to its already remarkable resume. After a year and a half at asteroid Ryugu, collecting samples and blasting an artificial crater into its surface, Hayibusa-2 dropped its sample capsule off at Earth in December 2020

and just kept going. The extended mission renamed Hayabusa-2 Sharp, sharp as in the musical notation, set a course for the tiny near-Earth asteroid called 1998 K-Y-26, with a rendezvous plan for 20, But on the way, the team lined up something extra, a flyby of an asteroid we now know as Torifune. Torifune is named for Amen No Torifune, a divine ship from Japanese mythology that carried gods between heaven and earth.

Jaxa picked the name through a public naming contest, which you know we love here at the Planetary Society, after all the ones that we've helped organize. The flyby happened on July 5th, and it was a genuinely difficult piece of flight. flying. Hayabusa 2 was never built to do flybys. It was designed to pull up alongside an asteroid and stay for a while, not to thread a needle at high speed. But the spacecraft found was a contact binary, two objects that came together and stuck, kind of like a cosmic snowman. Joining us today is Dr. Paul Abel, NASA's chief scientist for small body exploration at Johnson's Space Center. Paul has been part of the story from the very beginning. He was on the

recovery team in the Australian Outback in 2010 when the original Hayibusa spacecraft brought home the first samples ever collected from an asteroid. And after a journey so troubled, it's a minor miracle that that capsule actually made it back to Earth at all. Since then, Paul has served as a bridge between Jaxa and NASA, helping the Hayabusa 2 and Osiris Rex teams share some really hard-won lessons about landing on Boulder-covered worlds. He's been on both of those science teams on the double asteroid redirection test or DART investigation team, and he has an asteroid named after him. 8139 Paul Abel. Hi, Paul. Thanks for joining us. Hey, Sarah. Happy to be here. It's such a fascinating realm of study, and I think most people, their ideas of studying small

bodies and near-Earth objects mostly come from movies and Hollywood. But, I mean, the fact remains, this is a realm of science where you can make a mark a difference in potentially saving the world someday. Do you ever feel that as you're doing this kind of science? I mean, yeah, I mean, one of the things where I originally when I was in astronomy, right, in undergrad, I was looking at things like that were quasars and galaxies and, you know, there were many, many hundreds, if not millions of light years away. For me, I was like, that's why I got hooked on the near-Earth asteroids because that's something that can be realized now and make an impact today or to,

tomorrow or in the very near future for people, right? Humanity. And so that's one of the things that attracts me about it, right? We're now to the point where we can go out and touch, in air quotes, tag and all that and these objects. And my first real experience with the Near Earth asteroid mission was while I was in grad school, I was very fortunate to be part of the near SchuBenker mission to Asteroid Eros. And that's how I cut my teeth on. missions and it was it was there that one of the lead scientists I remember named vividly and I was sort of his assistant was Dr. Joe Verka and he he said you should get into this you should do this more often and so I was like yeah sure okay you know I'm not really thinking you know

I was like okay this this gentleman is respected he said that and I had no idea and yeah I did I just I just followed through with it but that you know precisely what you said is the near-earth asteroid population of small bodies in the inner solar system can really make or make or break humanity, literally, right? We're all going to have a very interesting time in 2029 with Apophis. Oh yeah, I can't wait. I can't wait. That's going to be actually tremendous. And there's so many of us in the field are just so excited for what we're going to see and experience at that time. So, Sarah, I originally from Canada. I grew up in a very small town of 500 people, a small town about 120 miles due west of

Winnipeg, Manitoba, a place called Wauanissa. And obviously, in the middle of the countryside, very rural farming, and no lights. You know, we didn't have a stoplight, so very little light pollution. So as a young boy, I used to be fascinated with the night sky. Of course, Canada with no light pollution, but in wintertime, skies are dark for much of the evening, right? It starts getting dark around three, four o'clock and stays dark quite late. And so I used to go outside in my snowsuit and lay in the snow, literally, and look up at the sky. And I was just fascinated because there was so many things to see.

I mean, the stars were like diamonds, you know, they didn't, twink. everything was so cold it was frozen out. We had Aurora, we had shooting stars, meteors, satellites, everything. So I was just fascinated. A funny story. My mother would freak out because it would be cold and she'd have to check on me every 20 minutes and yell out the window or the door to say, hey, are you still? I'm like, and if I didn't respond, she'd come running out. So yes, I had to make sure that I responded to let her know that I had not frozen it yet, but I was just so into it. So that's, That has got me started in that whole realm of sky and space, but I got recruited by NASA, NASA Johnson Space Center, six months before I defended my thesis. Oh, wow. What a time in your life.

Yeah, it was amazing. It was like I finished, I remember it very vividly because it was kind of a hair of fire experience. I defended my thesis in December of 2003 and January 2004 I started working at the space center. So, yeah, it was, I mean, long story. No pressure. Yeah, I know. It was great. And I've just never looked back ever since. I've been so excited about all these sample returns because the stuff that we're finding in some of these missions, starting with Hayabusa and moving on to all of these, we're finding these complex carbon chains, the building blocks of life, all the things that we've seen and things like DNA.

We don't have life yet. haven't actually found full nucleic acids or anything, but it bodes so well for our understanding of where life in the universe came from. So there's this whole other aspect that I think a lot of people in the public don't think about when they think asteroids. Right. I mean, the asteroids are so rich, I mean, metaphorically and figuratively speaking in terms of the science that they can provide us, right? They're the leftover building blocks of the early part of the solar system. So they're very ancient materials, but they tell us a lot about things like how the solar system formed, what it was like, how the Earth Moon system formed, how Earth had its water delivered to it, and as you said,

how some of the prebiotic molecules may have been delivered to Earth and how might life have evolved on Earth itself. So they're really, really fascinating from a science point of view. And the sample return missions, the most recent ones, so Hayibusa II went to, that was the the Japanese mission that went to Rugu, and our own mission, the NASA mission, Osiris Rex, which went to Benu, both brought back very, very interesting materials from what we call carbonaceous type asteroids, both Rugu and Benu were carbonaceous material, and very similar to some of these carbonaceous meteorites we find on Earth, and they're just chalk full of these prebiotic molecules and also very rich in some of the volatile material, especially water.

So it actually is a trevor trove of information that really tells us how life may have evolved on Earth. So it's an amazing time. I know you've actually been to experience one of these samples coming down to Earth. What has that actually been like? Yes. So you're referring to the original Hayibusa mission coming back to Woomera, Australia in 2010. And it was an amazing experience. So I was on the contingency recovery team, which basically means you have a prime team,

which is designed to take care of everything in the nominal case. Everything works perfectly, right? The contingency team is a smaller subset of the larger team that is designed to make sure, hey, if something goes wrong, like the parachute doesn't open, or the capsule comes in short or long of the intended landing site. But there's someone there that can be deployed quickly to take care of things and just make sure that the integrity, the scientific integrity of the sample is still maintained. And so that was my job. And so I remember it was a fascinating day.

I can still visualize it. It was, you know, midnight in the outback. I was up in a place called near Cooper Pedy. That was sort of our duty station. And I was on the end for if the spacecraft came in short from the landing site. Of course, everything went well. It was an amazing mission. I think the capsule came down within half a kilometer of the target point, which is truly amazing. And just seeing it come in and knowing that we had a sample and the confirmation from the base that they had locked on to the capsule, that the helicopters had found the capsule with parachute landed on the ground. Everything looked good. It was an amazing time. It was a very tiring time because we were up all night. But it was just such an exhilarating experience. we were living on adrenaline and knowing that we had those precious samples back here on Earth for the for the first time from a true asteroid sample return was was truly amazing.

Some of my colleagues actually got to go see Osirx samples drop down and I wish I could have been there to see it. It just sounds like such an amazing experience. It is. It's kind of hard to imagine, but you work so long. These missions are not just, you know, quick. They're not just a year or a couple of years. They're multi-year, seven to eight-year missions from start to finish. And that's just for the launch. I mean, you have a lot more at the pre-planning stages, the proposal stages, everything else.

And so a large part of people's careers are spent on these missions. So seeing the capsule come down safely, it's just one of relief and then just pure exhilaration and joy. Yeah. Well, you've worked not only on Hayabusa, but also you've helped support Hayabusa too. And you became kind of this bridge between the Jaxsa and NASA teams. What is it like building that kind of relationship across two different space agencies with two different cultures and two different missions that are both kind of chasing these same big questions? I would say it's rewarding. It was one of those things where I sort of was in the right place to the right time. And I realized, that there was just an opportunity for someone to be in the room who knew the science, but had a knowledge of some of the other operational issues and things. And also learning a little bit more about the culture and the differences in the culture between how we do things at NASA and how things are done for Jaxa, the Japanese Aerospace

Expiration Agency. It was there that I decided I'd learn to speak Japanese, right? So I learned Japanese, a little bit self-taught. I had some classes, and I'm still learning Japanese. Learning about the culture, being there. I usually get over to Japan once or twice a year and maintaining that. But they have a different way of looking at things, just like we have a different way of looking at things. And one of the beauties of working with them and being sort of a liaison in that sense to Jackson, between Jackson and NASA,

for these small bodies missions, both Hayabusa and Hayabusa 2, you're able to tease out the best of both worlds and help both the science teams and the management teams for the spacecraft missions work together. So specifically, Hayabusa 2 got to Rugu first, right? And that was planned. That was a separate mission all by itself that Jackson was going to do. We had our own mission, Osiris Rex, that we'd planned and get a sample return, different target venue. And this was done independently. There was no coordination between the teams. But then, of course, I was on Hayibusa II.

I was also on Assyrus Rex, and I saw an opportunity to try and help bring these. And it wasn't just me. There were other people who also saw this opportunity. But I was in a unique position because I had previous experience with Hayibusa and the people involved and a lot of overlap with the Hayibusa 2 team. So it was a good situation. And I remember seeing Rugu for the first time and, like, Oh, wow, there's lots of boulders on there.

Huh. How's that going to affect our mission, Osiris Rex, if Benu is like that, right? So there was a lot of cross-talk. There was lots of lessons learned. And it truly was an invaluable experience. I will say that the Japanese way of doing things, they take a little bit more risks in terms of how they do it. We're a little bit more cautious. But they tend to really, really go for it.

And I think it's nice to see that. and they pulled off some amazing results and amazing operational results. And it's good to have that. At the same time, we have a way of doing things that is very, very precise. Our instrumentation is really, really good at teasing out information from remote sensing. And the amount of sample we got, comparatively speaking, from Osiris Rex with respect to high abuse of two was a lot larger, right? So they were in a sense they were different missions. There was a lot of overlap.

The teams were embedded. We had membership from Hayibusa 2 and Osiris Rex and vice versa. And there were lots of lessons learned, especially from the curation side, the sample storage side and how to store samples. What are the lessons learned from storing those samples, keeping those samples pristine, how to handle those types of samples. So it was really rewarding to see that that all come to fruition. I'd like to think that I help play a role in making both missions be more successful, but also actually, if you think about it, getting the most, getting another level of information out of both missions, so working together.

And you'll see that even now we're still cooperating and having this whole new realm of curation on small bodies and the knowledge that we were gaining, because we're going to do this again, right? Maybe not NASA per se right away or maybe not Jackson right away, but there's going to be plans. You know, people are going to send spacecraft to asteroids. We're going to get more samples. And so all these lessons learned are going to be really invaluable.

That spacecraft almost buried itself in that rebel pile when it tried to grab that sample. So who knows what could have gone even more wrong without that collaboration? Well, I will tell you with the collaboration, it helped. I mean, I helped facilitate a team meeting between the Hayibu's navigation team and the close operations team. when I say Navigation, right? And the Osiris Rex team. And it was in Sagamahara in the Jaxa Planetary Science Institute, so ISIS. And it was to discuss how would you, you know, what did they do to get down to the surface?

Because you had all those boulders. You know, if you look at the asteroids, you know, people originally when you had Hayabusa, they had this image of Iyakawa, right? And so you had these vast areas, I want to say vast, but 60 meter area of, you know, small, smooth, pebbly, beach, sand-type, you know, great place to touch down for spacecraft, no obstacles in the way, great. And so that was the sort of the mental image that people had, that there were going to be these areas on these objects that you go to.

And then, of course, we got to Rugu and it was like, uh-oh. And then Benu was like, oh, okay, this is even worse. And so the Japanese obviously went in first. They figured it out. And then we, with this meeting, were able to have learned a lot from them. And it was at that meeting that the PI, Dante, Loretta, decided, nope, we've got to change things up. So this is what we're going to do. We're going to change it up.

And it was because of that decision was made. It was instrumental in making sure that we could get down to the surface and get the sample that we did. So, yeah, it's super, super important to have this international collaboration. Well, you co-authored a white paper for the planetary science decadal survey that laid out these characterization priorities for near-Earth objects. basically what do we have to know about these things in order to potentially deflect them? And I think one of the things that really kind of stuck out to me is this fact that we can only learn so much from the ground with our telescopes. There's a lot that is really difficult to glean from this kind of distance. So how well can we answer those questions from the ground and why are these flybys so useful?

If you're just talking about planetar defense, which we're talking about right now, right. There's only limited amount of information you can get from the ground. And that's true for, you know, some of the science. And this goes back to some of the conversations we had about, you know, Benu and Rugu. I mean, the information that we got from our remote sensing from the ground on Benu was that all the infrared data and thermal modeling suggested it was going to be, there's going to be some smooth areas on there. It turned out not to be, right? For a variety of reasons. And so, yeah, surprise. And so I've been on some, other missions, every time we've gone somewhere, we've been surprised. When we get up close to the asteroid, they're so surprised. And that's great, because that's what it's all about. It's all about science discovery. When you're dealing with planetary defense, you do not want any surprises, right? That's the last thing you want. And I had a mentor who retired in the last couple of years from JPL, actually two, both Don Yomens and Paul Chodas. And they drilled into me, one, of the mantras. There's a couple other mantras, but this one in particular, which stuck with me is

when you're dealing with planetary defense, you don't get to choose the asteroid. The asteroid chooses you. And that's why you need to know as much as you can about the target. That's why these flybys that what I wrote in that white paper, that's why the flybys are one aspect are really important. Again, those flybys are more important when you don't have a lot of warning time, right? You want to get out there quickly and see what you're dealing with. If you have lots of time, you know, 50 years or more, oh, then sure, you can send a rendezvous spacecraft, right? And you get a lot more detailed information. But you got time to deal with it.

Sometimes you don't always have the time. Well, thankfully, with our actual missions, we do get to pick the asteroid, right? Right. And, you know, which allows us to look at just the diversity of all of these different objects out there. And Hayabusa, too, is really interesting because it went and it got this sample. And then it came back to Earth, deposited in December 2020. We got our mission accomplished. But the spacecraft was still healthy.

So that allowed Jaxa to continue its lifetime and go on to these other objects. But I am wondering, between dumping the samples back on Earth and this recent flyby of Torifune, like, what was Hayabusa 2 doing during that time? Yeah, it's actually a good story. The difference between Hayabusa and Hayabusa too. So Hayabusa, as it was coming back, as you know, was not healthy, right? That was really a tense time, right? Having a, the spacecraft was eventually pretty much crippled.

We were, you know, coming back in some ways sort of a wing on on a prayer. But it hung in there, and the Japanese team was, the engineering team was amazing. I mean, I refer that to sort of like the robotic version of Apollo 13. It was really amazing that they managed to get the capsule delivered with the sample. It was amazing. Hyabusa 2, completely different, much more healthy spacecraft, as you mentioned. So you've got a healthy spacecraft. You've done your prime mission.

What else can you do with it, right? And so the idea was, hey, we can carry on and look at some other asteroids, right? It's a solar-powered spacecraft. really should stay in near Earth space, near the sun, for operational purposes. Let's look at see, you know, here's their trajectory. Let's look and see what other targets we can get to. And so they actually came up with a trajectory. They wanted to go to a smaller target.

So their prime rendezvous target is an asteroid called 1998 KY26. It's a very small target. It could be only a few tens of meters across or maybe a little bit less, rapidly spinning, but very unique. and interesting. And we don't have much information on this type of the small body population, like really, really small asteroids up close and personal. So they targeted that one. And on that trajectory where they were going to do it, again, the samples were dropped off in 2020. The rendezvous is not until 2031. And so they've got time in between and they looked and they're like,

hey, we're going to be able to fly by this other asteroid. 2001 CC21 or else's a destroyed terrafune, Torifune, is it now non-named? And the flyby they did was amazing. That already occurred. But they had all that time. But still, between 2020, the drop-off of the sample, you've got the flybigh of Torifune, which is, you know, in 2026, which just happens. So there's six years there. And then you've got another five years between going to the other target. So what do you do, right? So the Japanese are amazing. They've done some amazing work. And the first thing they're doing is they're checking the health of the spacecraft, right? It's still an older spacecraft. They're checking all the ion engines.

They're checking how the instruments are working from the touchdown on Rugu, all the material that has been liberated. There is some degradation of the sensors just because there's material adhered from when they actually touch down in the pluming. But they still work, right? So they do all that. There's a lot of health checkout trying to figure out how the systems are working, how long a spacecraft can't exist in space. But they also have some key sensors. One of their key sensors is their optical camera, right, that they use for navigation, which they used heavily in this flyby.

And two things that they did, because they have time and they're in cruise. One is they looked at exoplanets. They actually did some exoplanet transits, and they looked a couple candidates. The plans, I think they're still looking at doing that in the future. So why not? Why not see what you can see? So they did some exoplanet research. They also did another project with zodiacal dust.

This is the dust that's mainly in the ecliptic plane with all the planets in the Earth. Thought to come from comets, but primarily asteroids. And you have these dust zones and zodiacal light. And it's very useful to know. These are small bits of dust that cause a background glow. You can actually see some of it. At sunset, you can see some of the effects of it. And it's useful to know because it adds to the background light.

And this is going to be important for our understanding, especially for our own mission that's coming up, the NEO Surveyor Mission, which is a planetary defense early warning system, as you will. It's an infrared telescope looking for asteroids. It will be situated between the Earth and the sun. It doesn't look at the sun, but near someward side. But anyway, understanding the zodiacal light and the contribution, especially in the infrared, that will help you understand your sensitivity of your detectors and what you can actually see. So some of this sort of incrues serendipital science that they're doing is actually really important for future, not only science, but for future operational reasons as well. Man, we're in such an exciting time for learning more about these objects. I love that they did some exoplanet observations too, because getting time on telescopes is so difficult.

I'm sure that the people who got to take that data were really excited to have one more tool in the toolbox. Oh, they were. They were ecstatic. They were so three. And keep in mind, the telescope on the spacecraft, yeah, you're out, you know, so you don't have to worry about weather and things like that. But it's very small, right? It's not very big.

So much smaller than the telescopes we have here on Earth. Yeah, maybe see some hot Jupiters or something. Yeah, exactly. Well, it was only recently about a month ago on July 5th that high up was a too sharp, actually flew by Torifune. And it was going maybe about five kilometers per second and got pretty close, about 800 meters. and it actually turned out to be pretty scientifically interesting. Can you tell us about what type of asteroid this is?

Yeah, so we have some good indications from the ground based in terms of the composition that this is an asteroid very similar to Asteroid Edakawa, so the original target of the Hayibusa mission, right? And so it is what we call an ordinary chondrite type asteroid or after the ordinary chondrite type meteorite. So it's a very common type of material. that we find on Earth in our terrestrial meteorite collections. We see this in some of the materials from our own Dart mission that went to Didomos and Dymorphos.

It's very similar to the type of material type that is thought to be making up the asteroid Apophis, which is going to pass by here in 2029, right, so that people are excited about. So this is a very, very common type of material. What was interesting about the asteroid itself was like we thought it was, we had some indications from the ground-based observations of the light curve. We knew the rotation rate pretty well. We had some indication that it was a bit elongated, but we weren't sure there may be some speculation about a contact binary, but this actually confirms it. And this is, it's actually really interesting. If you look at the images, which I encourage everybody to go online and find that you should

be able to see them, they're two lobes, right? And they're almost, I wouldn't say, they're almost equal, but not quite, but much more equal than, say, the two lobes of Idaqawa, which sort of more resembles an otter. You know, Ida Kowel looks like an otter with his head and smaller head and larger body. It kind of does. And Torifune has sort of like these two sort of, you know, spherical balls that are stuck together. The other thing is the, the size of the object is a little bit bigger. I mean, again, that's just, you know, from spacecraft, we get that better information. So it was turned out the average dimension is about 540 meters in length. We were thinking maybe, you know, around 450, 500 or from the ground. So again, having that spacecraft up close personal look, you refine that

dimension and you actually get an idea of what the surface is like. And of course, there's two lobes or the two parts of the asteroid covered in boulders, lots of big boulders. So it looks like a rubble pile. One of the interesting things to point out is, hey, there's some smooth areas on there. I don't know if you notice that, Sarah, and looking at some of the images, but there's some smoother areas down near the southern part of the object. So that's really interesting and be really interested to see what the material is like near the neck between where the two objects meet. We haven't got good imagery of that yet.

I'd like to point out that, you know, the data is still being analyzed from the mission. During the flyby, we took, when I say we, it's the mission, right? I'm part of the mission, but we. The spacecraft got about 300 megabytes of data. Because of the way the flyby worked, we only had three days to download that data because they had to operate the ion engines to get to the next target, which was KY26, right? So we only had a three-day window to download some of the data. So we got 25 megabytes of data downloaded.

The rest is going to be downloaded later from the spacecraft once it stops its ion engine operation to have the first maneuver to KY26. So there's a lot more data to come. I know that we have spectroscopic data from the spectrometer on the mission. We have thermal data that is being analyzed. We actually got LiDAR data, so laser ranging, which is going to be super, super cool. And one of the amazing things to me that blows me away is that we, the spacecraft got within 400 meters of the surface. That is the closest we have ever purposely flown by.

something, right, a small object like that. And keep in mind, it's, you know, sub-kilometer object, and we were screaming in at five kilometers per second. And this was not designed as a flyby spacecraft. This was designed for rendezvous. So hats off to the Japanese engineering team. Hats off to the JPL navigation team. They had a lot to help and play in that role as well. But they got within 400 meters, roughly. And they're still tweaking the numbers, but that's the latest number that we have. have on the science team. So that's tremendous, right? It shows just how close we can we can get and target these very small, small objects. That is really amazing. But this object is very small and dark. And my understanding is the team couldn't pin down the exact trajectory until a few days before

the flyby. So how nerve-wracking was that for everyone? Yeah, it's a little interesting, right? There's a couple times I remember being on the team and then we're like, well, you know, if we get too close, we actually might hit. So there was an email that was sent out to the observing community. It's like, hey, can you watch this asteroid around time of impact? Let us know if it gets brighter because we may have hit it. Unfortunately, that didn't happen. But yeah, no, there's always that concern.

You know, it's a little bit nerve-wracking. You want to get as close as possible, but not too close, right? Because it was a Rondehu spacecraft, the way the instrument deck was located, you had to basically come straight at the object in order to, to get your instrumentation in the right field of views, right? There was no way of slewing effectively. It just wouldn't work. You wouldn't get anything.

Again, this was a rendezvous spacecraft, not a flyby spacecraft. So completely different design than some of the other spacecraft that you may have known that fly were purposely made to fly by. And so, yeah, there's a little bit of nervous energy. Everybody was super pumped, though. And, of course, it pulled off and we got the images. and yeah, it was a big, again, one of those big relief moments, making sure we still had telemetry, knowing that the spacecraft obviously didn't hit, but got very, very close.

It was a tremendous feeling. We'll be right back with the rest of my interview with Paul Abel after the short break. Hi, Bruce Betts here, chief scientist at the Planetary Society. Our organization is strongly committed to defending our planet from an asteroid or comet impact. Thanks to the support from our members, we've become a receipts. respected independent expert on the asteroid threat. So when you support us, you support planetary defense. It's a lot to do, and your support is critical to power all this work. That's why we're asking for your help as a planetary defender. Together, we're advancing the global endeavor to protect

the Earth from asteroid impact. Imagine the ability to prevent a large-scale natural disaster. You can be part of this global effort, a gift of any amount to the planet. Planetary Society helps keep this critical search going, protecting our planet and everyone on it. Visit planetary.org slash defend Earth to make your gift today. Thank you. Well, surface, as you said, is covered in a bunch of these different boulders. Does the data tell us what these boulders are made of, or are we still waiting for more of that spectroscopic data? So the ground, the whole, so when you look at it from the ground, right, and this is one of

I think getting back to the questions of what can you can tell from the ground, what can you tell from the spacecraft. From the ground, you just sort of get a general, you know, whole hemisphere, you know, what's facing, what's reflecting the light off the asteroid back to the, back to the telescopes on Earth. And we think that's ordinary cundritic material, right? And that's the overall signal. The way to bet is, you know, just from me looking at the data and what I've seen so far is that that's probably, you know, a good bet that everything there looks to be ordinary cundritic. the spectra, we haven't had a chance to, there's a lot of calibration, they're still working on it, you have to worry about blurring,

some portion of the asteroid may be a little bit closer to as again, you're coming in at five kilometers per second. So some of your exposure times, it's interesting to see what you get, even with the spectrometer, what the area of coverage is that field of view. So there's a little bit of calibration, but my assessment is it's probably still going to be ordinary conunditic, right?

I don't see, I guess from the data that's been downloaded, I don't see anything that would suggest, hey, there's different types of material, right? And again, it's dependent on the resolution that we have. It's different from a rendezvous. If you remember from the data from Ayubusa 2 at Rugu and Osiris X at Benu, they actually discovered different types of materials on the surface that were, you know, different, different either really bright materials or some of the little bit darker materials, right? And so that tends to lend credence that, you know, there's some impact processes and some of these asteroids collect different types of materials on the surface. We don't see that yet from Torfune. Again, it may be a resolution issue. We did see that a little bit on Ida Kawa.

There's the black boulders. Again, don't know if those are different materials or if there were different shock types, maybe the same material, but just shocked. There's some different theories. But again, you know, that's the nice part about having. a spacecraft, again, with the rendezvous, you can take your time and focus in. On a flyby, it's like that quick snapshot, so you just sort of get what you get. Keep in mind, there's still a lot of data on the spacecraft that we have yet to download, so who knows? But my sense is from what we've seen so far, pretty much everything is probably going to be an ordinary

conundit type of composition. Based on how fast it's rotating, can we tell anything about how this contact binary formed? It's a good question. So the rotation rate is about five hours. It's relatively, relatively slow. Basically, we do know not so much from the rotation rate, a little bit more from what we think in terms of the model, the shape model, the structure, the boulders. This looks like a classic rubble pile, right? It looks like what we've seen on Itakawa, not identical, but similar.

Again, not identical, but similar to demorphos and didomos. This looks like rubble pile, right? So basically the idea is you have two asteroids collide together, catastrophic disruption, and then pieces fly off at low relative velocity to each other, right? So you have pieces that are sort of clumped and grouped together, and then through mutual gravitation or interactions, these pieces come back and form together, right? one of the interesting things is, and if you look at images from Darmorphos, Didamos, Iatakaa, and Torafune is you see lots of boulders. And you see this also with Rugu and Benu.

You see lots of boulders on the surface. But what we don't know is, is the interior the same? In other words, what we see on the surface is indicative of what's in the interior or are there larger blocks or larger coherent chunks inside? You know, so like, for example, in Torufune, those two main lobes, are there bigger pieces making up those lobes themselves? My sense is, again, from talking with some of the dynamicists who work on this and model this, it looks like, you know, these two lobes may have come into contact at low relative velocities each other to form Torufunei. So then basically you have pieces that come together and they formed one lobe, had formed a separate lobe, and then those two lobes actually came in together at low relative velocity and then sort of just stuck there, right? And then the object evolves over time and you get these, you know, rotation rates.

But in terms of the actual rotation rate, it doesn't tell us, it can tell us something about the formation, but more likely it's the actual surface, the shapes, the number of boulders. the density of the boulders and things like that that really tell us a lot about the interior structure. It's really cool getting more data on more of these objects and just the diversity of what we're seeing out there is really startling. But I do wonder if that diversity complicates our planetary defense efforts. Yeah, it's sort of job security. I mean, when you've got lots of objects out there, right, you just got a sheer number of objects that we have yet to discover. Again, I sleep well at night.

Your listeners should sleep all at night. You should sleep all at night. We're doing it. But, you know, we're here just in case, right? Just in case insurance. But there's lots of objects out there. But there's lots of different types, right? We have contact binaries.

We have true binaries. We have ternary systems. We have carbonaceous material. We have metal material. We have ordinary chondritic material. So there's lots of different types. And it goes back to the whole thing of, you know, there's a wealth of diversity. and that's great for science.

It does complicate things a little bit in planetary defense in terms of you really have to know what you're dealing with. You know, we have done DART. We have one data point on how we can deflect a certain type of asteroid. I would like to try and be ready for a few other alternatives, maybe three other scenarios, just to be ready, right? It's just like, you know, you practice for a play, you practice for a concert, you practice for a sporting event,

if you're on a sports team, we do planetary defense and we have to practice for that because we don't want to have to do it right the very first time. We need to practice and know. So, Dart was an amazing mission. I was on that. It was tremendous. But that's just to start this one data point. We need to try and expand our portfolio and look at things. Maybe we want to try and see if we can deflect things in different ways, right? There may be different techniques to deflect or stop an asteroid, maybe a different size of asteroid, right? How would we want to you target something that's 50 meters? You know, Torifune is about 500 meters, average 540 meters across.

How do you target something that's 50 meters, right? Dart hit demorphose, that was 150 meters. But now you're talking about something that's 50 meters. So it's, you know, you're stepping up the challenge in terms of dealing it with it operationally, but 50 meter objects, you know, if we're going to get hit again, that's probably the size that's going to give us the next problem that we'll have. have to deal with. So anyway, just something that we tend to think about here in planetary defense. Is there some concern that if we're hitting something like a contact binary, that we might break it into two pieces and basically make one threat into two threats, or are we not concerned?

Well, I mean, you always have that in the back of your mind, right? And again, that's why you want to know everything you can about the object. And that's why you're not going to, hopefully, unless you're left with no other choice and it's a last minute thing, right? But that's why we want to have, you know, we have the systems that we have, right? We have the ground-based survey systems that track and find all these objects that we have right now. Why we're planning to launch the Near Earth Objects Surveyor Mission, right, the infrared telescope, is to find all these damaging targets or a lot of them, right, and be prepared. And then when we, if we do see something coming, we have the time.

The other mantra that I will tell you, so the two mantras, the one was you don't get to choose the asteroid, the asteroid chooses you, but the other mantra is, you know, find them early, find them early, find them early, find them early, right? So you got to find them early and then you have time and then you have time to deal with them. And then having time to deal with them helps you being able to send spacecraft out there and know what you're dealing with, knowing, tailoring the specific mitigation method, you know, whether you have to deflect or disrupt on a basis of, what you find now for an asteroid or maybe even a comet. So those are the type of things that we want to be able to do. And if you have the time, if it is a contract binary, you know, obviously hitting it on the very edge is not great. It's not great for even a monolithic type. You want to be able to know everything about the target and where's the best place to deflect it, not only in terms of on the asteroid itself, but also in the time of orbit, right,

the location in the orbit. it, you basically want to slow it down or speed it up. You just want to make sure that it misses that conjunction point with Earth. Or if it's really, really hazardous and last minute, and it's small enough, then maybe you can disrupt it. But that's, you know, that's risky, and we haven't done that yet. So there's always things that you worry about. But again, having that time, having that information, gathering it so you can tailor the technique

to the specific object is always the best way. And that's how I'd like to think about it. Well, between NEO surveyer, we've got Vera Rubin and all of the other asteroid hunters out there. I do. I'm beginning to sleep much better at night knowing how many of these things that we've cataloged. But it is those small ones that are harder to detect that we really have to worry about. And I think that's what's so interesting about the next target for Hayabusa 2. This 1998, KY26.

It's tiny. and it's rotating really, really fast. Is that what makes it worth this trip? So we don't have a good, a lot of information about the small body, really, really tiny small body population, you know, the 20 meters and less. And so going to these very small objects, having them rotate really quickly,

you know, there's some question of, is this a solid piece of something, or does it have some internal cohesion or strength? There's something that we don't understand that even though it's a rubble pile, it allows to spin that quickly. people think it's got to have some type of internal strength. So it's a solid object to spin that fast, right? But knowing how these smaller objects are like, how they're put together, what's their composition, how do they interact. You know, this is something that Hayabusa 2 is going to find out.

One of the neat things about Hayabusa 2, two aspects that I will share with you, is we still have a tantal and projectile from the sampling system on the spacecraft, right? So this is a 300 gram of all intensive purposes. Think of a bullet. And so, you know, they're talking about going up and then rendezvousing with the target and then shooting that tantal and projectile into it and forming a crater and seeing what happens, right? And so that'll be really interesting from a scientific experiment. The other thing they're going to do is towards the end of the mission, you know, after they rendezvous and get all the information they possibly can, they're going to try and land on it. And so there's something that's spinning like, once

every 11 minutes. That's going to be really challenging doing that robotically. So they're going to have to try and do that from on the pole, right? On the pole, you can get away with it. But that's something they're going to try and do. So we have all this data that we still have yet to analyze. But I'm really looking forward to KY26 and the rendezvous opportunity and the science that we may get. Again, I got to be patient because, you know, I got to wait another five years. The team has to wait another five years. But yeah, it's a very exciting time. And in the meantime, we've got all these other fantastic missions that are going on. We've got our own launch of Ennio Surveyor, maybe sometime next year. We've got Hera arriving at the Didomos DeMorpha system later this year. It's going to be

amazing. And then, you know, we've got in 2029, we'll have, you know, three spacecraft to encounter Apophis, right? We've got Destiny Plus, which Japanese is going to fly by Apophis and early February of 2029. Then we have Ramse's, which is a sort of a European space ASEC mission following on the sort of the guidelines of Hara that will rendez do with Apophis in late February of 2029. And then we have our own spacecraft, the Cyrus Apex, that will get there in June. So it's going to be an exciting time. In 2009 is the International Year of Asteroid Awareness and Planetary Defense. Lots of amazing things are going to happen starting very soon leading up to that international year and during that international year. So it's an exciting time for for small body

science and planetary defense. Well, as we're looking ahead to all the things that are coming up in the future, what are you most hopeful that these missions are going to enable us to do in the future? That's an amazing question. And it's something that I think about and there's so many aspects to that, right? I mean, for science, I just hope that, you know, it's not practical to go to every asteroid and get a sample of it, right? But I'd love to be able to do that, but that's, but you can't do that. But one of the things these missions do, especially aneo surveyor, will be able to help us find a lot of what we call low delta V targets, right? Low energy targets that come close to Earth that are easy, easier to get to from the standpoint of a spacecraft trajectory, right? We just don't know where

to look. So having that capability will be an amazing boon, not only for planetary defense, you get to see what's coming at you, but you actually get to see what's coming close to you, and that provides opportunities for spacecraft missions, right? And that's not only science missions, but that's also for mining missions, ISRU missions, right? There's companies out there that are looking at trying to see if they can extract resources from these asteroids. And, you know, the information that we've got from Hayibusa 2 and Osiris Rex suggests that there are lots of material there that's very interesting. And then you've got the whole planetary defense. aspect, but then you've got the expiration aspect, right? Wouldn't it be cool? You know, if we're trying to

shake down missions to Mars, right? Right now we're focused on the moon. We just did Artemis 2. We did a flyby, you know, around the moon. And wouldn't it be cool to test out our expiration systems? Mars is a long way away, but there's some nearest asteroids that are in between us and Mars. We could go out and have a human mission to an Earth asteroid and then come back, right? And At the same time, you're testing your operational capabilities, your spacecraft systems, life support systems as you're stepping away from the Earth-Moon system and then starting to explore the solar system with the idea of getting out to Mars and then other destinations. But at the same time, you know, learning about these really valuable objects, not only from

the standpoint of science, but mining and planetary defense. That's my hope. That's my desire. You're calling up all these science fiction, future ideas and my brain from for all mankind or the expanse, right? People in the future using these as resources. It's just amazing what this kind of science could enable us to do in the future and what it could do for humanity, not just for planetary defense, but for resources that we might

need for our technology and who knows what else, right? So it's really cool knowing someone like you who's seen the entire arc of this. I cannot wait, not just for us, but for you. When we get to KY26 and when we see Osiris Apex, all these things, I'm sure it's going to be such a culmination of everything you've done in your career. It's going to be tremendous. And I'm super excited about the future and I just can't wait. Well, thank you so much for joining us, Paul.

You're absolutely fascinating. And I think this conversation is just a great example of why this kind of rendezvous science with asteroids is so important. Well, thank you, Sarah. I appreciate it. Fun Sarah fact. I actually studied Japanese in college, so I've always had this soft spot for Jackson missions. They're constantly defying the odds of what's possible, whether it's nursing and injured spacecraft home on ion engines alone, or pulling off a flyby that their spacecraft was never designed to do.

They also have a bit of a habit that I personally appreciate. They really like firing things into asteroids. Which brings us to what's up with Dr. Bruce Betts, our chief scientist here at the Planetary Center. Society. Hey, Bruce. Hi, Sarah. How are you doing? Doing well.

I survived Nyak, the NASA's innovative advanced concept symposium. We'll hear more about that over the next two weeks, but glad to be back in California. It's not supposed to be a challenge, but it sounds like you had quite the trip that I assume people will hear something about. Yeah, you know, it was quite an adventure. But I'm not going to tell the story right at this moment. But, you know, in any situation, any time I have the joy of getting to be at one of these conferences. I think I talk to so many people and I hear so many

stories. By the time I get home, I am so full of new science knowledge that I just need to veg out. So my plan this week is to talk about Hayabusa 2 and get a little chill. Well, I don't know that it was really that chill omission. I mean, chill while traveling through space, but it shot an asteroid a couple times. Right. Take that one for the dinosaurs. I actually noted that, though, as I was talking with Paul Abel about this, he mentioned the different projectiles that were on Hayabusa 2. And there's two different kinds. There's that the small carry-on impactor, and then there's the tantalum one.

And he mentioned that they have a spare tantalum one that they might be using on their next target, 1998, KY26. We need a cuter name for that. But I wanted to talk a little bit about the SEI. the small carry-on impactor, because this is such a cool story. And the fact that we're just going around shooting asteroids, you know, for science is just amazing. For science, if you could tell us a little bit about what happened there, because like, why are we shooting asteroids? Well, here is there are different reasons. So the DART mission was shooting asteroids primarily to practice planetary defense and changing orbits of asteroids in case one comes for us, whereas this was to,

do things like uncover the material that hasn't been as modified by the space environment underneath so you can study it. And even in the case of their sampling, they used kind of a big funnel sample horn thing that actually collected the sample by shooting the asteroid when they were up in contact. And then the material flew up into their sample horn. And that's how they collected at least one of their samples. So that was the first tantalum projectile, right? Did the sample thing. Now we got one more of those.

Tantilum, that's exotic. Tantilum. But before they even took that sample, right, they shot it with something else. Cheese? I think it was hypervelocity cheese. Yes, they shot it with the small carry-on impactor. They shot it with that first to expose material. So I think they went and sampled that material, but they certainly did spectroscopy of it.

because you do, oddly in the vacuum of space, because of things like solar wind and cosmic rays, you do modify the surface. And so if you want to get a less modified surface, you want to clear off the top stuff. That's less true than if you're on the earth and you have water and humans and plants and stuff that gets in the way of the geologists. But still, that's it. So they made it greater. So when we talk about DART, we had that situation where we can't actually, like, they're waiting for the Hara follow-up mission because they had to give it some time to chill out after they blasted that object. So how did Hia Busa 2 deal with the fact that they blew a bunch of debris off of this object?

Yeah, this was very cool. They have the best gadgets. And so they had a separate camera that they let loose to try to capture the impact. And then the spacecraft went and hid on the other side of the asteroid. So none of the material would come flying at it. It was quite the clever and difficult to do thing, which worked. So cool. This is all happy.

Although it's going to be a different situation if they, you know, when they make it to 1998, K-Y-26, that object is so tiny that, like, what if you just shoot it and the whole thing flies apart? Then just make sure you take pictures. You know, valid. And actually, and we would learn something. I don't think that's going to happen. But if it did, we'd sure learn something about the structural integrity of that particular astride. Right.

But we also learned things from the impacts. So you get an idea of structural integrity, perhaps not of the whole asteroid, but are you dealing with? Because asteroids come in all these different flavors, it turns out, from iron, nickel, things that were inside a proto planet and then got ripped apart again, where you've got basically metal asteroids. And then at the other end of the spectrum, you've got these fluff balls, think. And then you've got the boulder piles, the rubble piles, which we've been encountering a lot of with, recent spacecraft like Benu and Osiris Rex that are just gravity fairly loosely holding together a bunch of rubble. You know, like there are those things that you know you shouldn't do, but your brain wants to do them. Like, you know, if I could jump out of an airplane and go right

through a cloud, like that would be a terrible idea, but like would be really cool. I just want to jump into one of these asteroid ballpits and see what that's like. Terrible. idea. I'm sorry, asteroid ballpins? Yeah, rubble piles. We'd have to fire you into it, though, just valid. Yeah. Sarah has a projectile. A larger carry-on impactor. Right. Sarah, it can still be CIA. Sarah carry-on impactor, perfect. This is a brilliant, brilliant idea. Another one, chalk up another brilliant idea for the team of Sarah and Bruce. Well, that was exciting. I don't want to get you too excited, but um, Random

Street Rewan. So this is, so space, humans, the world record holder for the most time and space is Oleg Kononenko at 1,111.

Yes, that's four ones, days over five ISS missions. That's three years. in about 15 days that he's spent in space. That is so long. Yeah. Imagine how that changes your brain and your body being in space that long. Like, that's cool.

Or terrified. One or the other. Keep coming back to the space. Terrifying. I think he's in space. It's the fact that his brain changed. That's cool. Yeah.

I mean, you know, it's just one more reason why, you know, we need to study more of these things, but also another reason to appreciate Earth. because we're kind of made to be here. It's true, it's true. Okay, everybody go out there, look up the night sky, and think about spending your time in space. Firing Sarah into an asteroid. Yay!

We! Thank you and good night. As a heads up, keep your eye out next month in October for the launch of Jax's MMX mission. That's the Martian Moon Explorer. It's headed toward Mars's moon Phobos to bring back the first samples from the Martian system. other than meteorites, of course.

We'll be covering that here on Planetary Radio, in part because it's amazing science, but also because Planetary Society members helped fund HoneyBee Robotics Planet Vex sampling instrument, which is on board. We did that through our Step Grant program, so thank you to everyone who helped donate to that campaign. We've reached the end of this week's episode of Planetary Radio,

but we'll be back next week with more space science and exploration. If you love the show, you can get Planetary Radio T-shirts at Planetary Radio, planetary.org slash shop, along with lots of other cool spacey merchandise. Help others discover the PB&J, the passion, beauty, and joy of space science and exploration by leaving a review or rating on platforms like Apple Podcasts and Spotify. Your feedback not only brightens our day, but helps other curious minds find their place in space through planetary radio.

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Kate Howells and Mark Hilverta are our associate producers. Casey Dreyer is the host of our monthly space policy edition and Matt Kaplan hosts our monthly book club edition. Andrew Lucas is our audio producer. Josh Doyle composed our theme, which is arranged and performed by Peter Schlosser. My name is Sarah Al Ahmed, the host and producer of Planetary Radio. And until next week, Ad Astra.