Planetary Radio: Space Exploration, Astronomy and Science - Last Week, Mars. This week, An Asteroid Called Bennu.

Episode Date: December 5, 2018

The InSight lander has only just arrived on Mars. Now, OSIRIS REx has reached asteroid Bennu after traveling through deep space for a year and a half. We’ll talk with the Planetary Society’s Jason Davis about this mission that will bring a sample of Bennu back to Earth after it has learned all it can over the next 19 months. We’ll also hear from the young student who gave the asteroid its name. Then we’ll return to the Red Planet for a conversation with the leader of the InSight mission, Bruce Banerdt. We’ve got very special prizes for this week’s What’s Up space trivia contest. Learn more at:  http://www.planetary.org/multimedia/planetary-radio/show/2018/1205-2018-osiris-rex-bruce-banerdt-insight-pi.htmlLearn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Last week it was Mars. Now we've arrived at an asteroid. That's this week on Planetary Radio. Welcome. I'm Matt Kaplan of the Planetary Society with more of the human adventure across our solar system and beyond. You heard the excitement when InSight landed on the Red Planet. Here's the compressed OSIRIS-REx arrival at asteroid Bennu. Stand by for Bennu arrival. So you can see here we have the Doppler residual, so we know the burn is occurring

because I'm seeing a change in velocity from the spacecraft. It's gotten very quiet in here. Everyone's whispering. We have arrived. You may have noticed we were doing a bit of an unusual high-five there. That's called the tag-five, because that's reminiscent of the TAGSAM arm that's eventually going to retrieve a sample. So we're just going to sort of watch people enjoy themselves. We have arrived at the asteroid Bennu. The spacecraft has successfully done the engine burn to put us into proximity operations at this asteroid. That's OSIRIS-REx communication system engineer Javi Serna talking with Michelle

Fowler of the Goddard Space Flight Center, a science communicator and astronomer there, who was the host of the live coverage of the OSIRIS-REx arrival at asteroid Bennu. Somebody else who was part of the celebration on Monday, December 3rd, was our own Jason Davis, digital editor for the Planetary Society, who is with me now. Hi, Jason. Hey, Matt. Always good to be here and talking to you. I know you were with a crowd of people and the mission principal investigator, Dante Loretta. Where were you? I work remotely here in Tucson, Arizona, and the University of Arizona, also in Tucson, is where the science part of the mission is headquartered. Donte,

of course, is a professor here. This is a PI-led mission, so this is one of those missions where a scientist actually is kind of in charge of the mission, of course. Ultimately, it's NASA's spacecraft. So I was here at the university watching with all of them, watching as the live broadcast came in from Lockheed Martin when they finally actually arrived at Bennu. So it was pretty exciting. I find it interesting that this was exactly, almost to the moment, one week after the arrival of InSight on Mars, when, of course, anybody who heard last week's Planetary Radio knows that we were with a big crowd waiting for that event. Did it get crazy there? It did. People, you know, there's kind of a space contingent in Tucson that, you know,

when I go to these events, I see the same kind of people like the local worldview folks, the dignitaries from the university. So yeah, it was a big crowd. Yeah, a lot of cheering and clapping when they finally had that big moment. Very much as we had in Pasadena at Caltech. So what does this arrival actually mean? That means that they are actually now starting close flybys of the asteroid. You know, they've had it in sight for quite a while now. The actual arrival time was slightly arbitrary. They kind of just needed, partly for PR purposes, to just pick a good time to say, hey, we're here, we've made it. And they picked this

arrival burn. So they were already creeping up on the asteroid. And what actually happened Monday was a 22nd engine burn that put the spacecraft on target for a flyby of the North Pole. So they were already about 20 kilometers away from the asteroid at that point. Now it's going to buzz over the North Pole and get its first up-close look at asteroid Bennu. I believe that by the time people hear this conversation, that that flyby will have already happened. What will they accomplish in this very low pass over the North Pole? They're going to start turning on some of the other science instruments. The main instrument that's going to be turned on during this first pass is the laser altimeter, and it's a Canadian-provided instrument. So they'll start

doing these high-resolution topographic maps that they're going to do all next year, actually, when they kind of, throughout 2019, survey the asteroid carefully. And during one of these passes, I believe it's the third pass, they kind of zigzag back and forth across the top. They're learning how to fly the spacecraft. And this is kind of the same thing that the Japanese mission Hayabusa 2 out at asteroid Ryugu. You don't really orbit these asteroids so much as you kind of deal with them, you kind of rendezvous with them because they're so small, you can't really just orbit them the way you'd orbit a planet. So they kind of zigzag around them and kind of station keep and things like that. What happens when they first get there, there's this initial period where the people who are flying the spacecraft, and in this case,

it's the folks at Lockheed Martin in Colorado, they're learning how to fly with this object that's kind of slightly pulling them towards it, but not pulling them super strongly. And so they'll be checking out the spacecraft, getting comfortable with it. And the other thing that they're turning on, the other instrument they're turning on is the map cam. It's already taken a few images, but it's a high resolution camera for kind of close ups. And it's in color as well. It has color filters. So they'll turn that on and get some cool pictures of the North Pole. And hopefully we'll see those in about a week.

I love the way you describe this. Deal with it, says Oscar with Bennu. I also find it oddly appropriate that this was taking place in a dance theater at the University of Arizona because it really does seem like the spacecraft, OSIRIS-REx, is going to be doing a little bit of a dance for the next many months over Bennu. Yeah, yeah. It's just kind of this weird orbital dance between two objects.

And, you know, that's actually part of the thing they're studying for this mission. OSIRIS-REx's presence around the asteroid will actually be enough to shift the momentum of the asteroid a little bit. It's, yeah, so they're testing out, and that's been theorized as one possible planetary defense thing that they could do, you know, to kind of shift it off course a little bit.

Because it's only 500 meters wide, and the spacecraft has mass in and of itself, it actually does have a little bit of effect on the asteroid. That's fascinating. There's a gravity tractor, is that technique you're talking about, right? Yeah. Remind us of when, well, there are two climaxes in this mission, or maybe three. We may have just had the first one. The next one, I assume, will be when the spacecraft finally descends to the surface and collects a little bit of Bennu. When is that going to happen, and what are the challenges they face?

that going to happen and what are the challenges they face? Yeah. So nominally, if you can imagine they've planned it out this far ahead, it would happen on July 4th of 2020. So that'll be quite an independence day here in the US to celebrate. What they have to do before then, of course, is find the right spot to take the sample. Again, going back to the Japanese mission Hayabusa 2, this is a very rocky boulder-strewn asteroid, just like asteroid Ryugu. So they have to find a place where they can bring the spacecraft in without kind of banging it off of a big rock or boulder, because that would obviously be very bad for the spacecraft. So throughout 2019, they're going to be surveying the asteroid and finding that perfect spot where they want to come in and do that. Then they'll come in on,

like I said, nominally July 4th, take the sample. And then eventually they'll leave the asteroid and they have a specific return date in 2023 where the sample will be brought back to Earth. Wow. We'll have to hope that, as so many of these spacecraft have, that OSIRIS-REx is able to do its job for the next, what would that be, four and a half years or so, I guess. It's quite a challenge ahead, but a lot of science to do between now and then. And you do mention some of the initial science

is going to be talked about at an upcoming conference. Yeah, at AGU in Washington, D.C., they have a press conference scheduled for December 10th, and some of their initial science is coming out then. I believe included in that will be their high-resolution shape model, or at least the highest resolution that they have of the asteroid at this point. From what I've heard, it pretty closely matches the radar observations of Bennu they took. So go team radar for getting an accurate idea of what this thing was before the spacecraft got there. And AGU, American Geophysical Union, of course. I assume

that you and maybe our colleague Emily Lachter-Waller are going to continue to follow this mission. Of course, we'll be right on it. And you can see everything Jason witnessed on December 3rd when Osiris-Rex arrived at Bennu in his December 3rd blog post that summarizes his experience and has some terrific graphics, including this approach video that you get to see this very pebbly Bennu asteroid as OSIRIS-REx approached it. It's very dramatic, and there's some other great stuff there as well. Jason, it's a great read.

Thank you very much for that and for joining us again on the show. Thanks, Matt. Jason Davis, our digital editor at the Planetary Society. One more tweet before we move on. Michael Puzio is now a high school freshman. He was just nine years old when he quite literally put his mark on the solar system. Here he is talking with host Lulu Garcia Navarro, of course, is an Egyptian god of the dead. I saw that he had been killed by his brother, and he returned to Earth in the form of Bennu. Bennu is depicted as a heron in old Egyptian drawings, and Puzio thought that the Osiris-Rex spacecraft looked like the bird with its long neck and wings. So Puzio, along with 8,000 other students from all over the world,

sent entries to the Planetary Society, which held the contest. And after a year, the group chose Bennu to replace the old name of asteroid 1999RQ36. When my dad told me I had won, I freaked out because I'd forgotten about it. In 2016, Puzio was invited by the Planetary Society to watch the official launch of OSIRIS-REx on its way to Bennu. That was awesome. When that countdown went off, Bill and I told me, the first thing you're going to do is you're going to see the rocket. Then you're going to hear the rocket.

And then you're going to feel the rocket. And I didn't know what he meant until we felt the building shake. And that was really, really cool. Asteroid Bennu namer Michael Puzio talking with Lulu Garcia Navarro. We're grateful to NPR News for giving us permission to share that excerpt. Back to Mars, where its newest citizen is settling in. The InSight lander has begun to flex its muscles in preparation for the real work that is still ahead. The leader of the InSight mission is Principal Investigator Bruce Bannard of the Jet Propulsion Lab.

Bruce was my guest last May when he gave us a nice preview of InSight's arrival and the work it would do. He rejoined me for an online conversation just hours before we published this episode. By the way, Bruce told me offline that the spacecraft has already begun delivering tantalizing data. This is happening even before its seismometers and deep drill have been placed on the Martian surface by that robotic arm. Bruce, welcome back to the show. Congratulations on that tremendous success that so many of us watched last week. You had 1,000 of us at Caltech gripping the arms of our chairs in anxious silence.

And then we exploded with, I think, the same joy that you were experiencing at JPL. So thank you for that glorious experience. I'm pretty thrilled about it myself. We had almost 1,000 people here at JPL and another couple thousand down at the Pasadena Civic Center, you know, the friends and family of the team, and probably got picked up on the Caltech seismographs, I think, when we landed, everybody jumping up and down. But I haven't checked on that yet, but I suspect we might have gotten picked up on the seismograph. I don't know. Are those seismographs as sensitive as your seismometers

that you'll be putting on the surface of Mars pretty soon? Oh, yeah. They're good and sensitive. They can't stand up to the rocking and rolling that we do, but they're pretty sensitive. Well, I'm going to come back to those seismometers. But first, tell us about this landing site. Is it everything you were hoping for?

Well, from what we can see right now, it looks really, really good. Definitely near the top end of what we were hoping to see. So far, the imaging coverage we have landing site is pretty limited. We've got that 120 degree fisheye view that we got down just a few minutes after landing that showed us a very smooth sandy surface in front of us so it looks like it's going to be really easy to deploy our instruments and there's rocks out in the distance that some of which may have given us a little trouble if we if we landed out there but actually none of those are are terribly threatening either so we think it's kind of a sandbox you know, maybe an old crater that's been filled in

with sand. And that's good for the mole especially. Seismometers are not quite as happy about it. They actually like firmer ground, but we're looking forward to testing the properties of the soil and seeing just how much that's going to affect the noise in the seismometer. Nice work, Insight, coming down in a pretty good spot. There was some mention of a pretty good-sized boulder off in the distance, which could have been a spacecraft killer. Is that the case? Well, we've actually been able to sort of triangulate on that boulder using the combination of our ICC, our context camera that I talked about, and the one image we have of the horizon from the IDC, our arm camera. That thing's about 20, 21 meters away, and it's probably about 40 centimeters high.

And technically, we can land on anything up to a half meter, but that's getting pretty close to the margin. So it probably wouldn't have killed us, but it definitely would have given us some concern and some heartburn if we come down on top of that or if one of our legs had hit that on the way down. Yeah, just as well. You're a good 21 meters away from it. Those images that you've talked about, yeah, they're limited, but they are terrific. And the one that I found both beautiful and exciting actually shows, it's two images, it shows InSight's long arm being unlatched or unlocked. Was that kind of a relief for you and the team?

Yes, it was. Of course, without the arm, we don't really have a science mission. We can't really do our measurements on the deck without serious, it was. I mean, of course, you know, without the arm, we don't really have a science mission. You know, we can't really do our measurements on the deck without serious, serious degradation. So that arm is kind of the next really critical link in getting from our dreams on the Earth to actually bringing data down from Mars. It's going to revolutionize our understanding of the interior of the planet. our understanding of the interior of the planet. And so if you see a series of pictures, you can go from, you can see the scoop of the arm just move by just a little bit and then back again. And that little motion was actually the motion that unlocked the arm from the deck. There's a hook on the back of the arm that, on the back of the scoop rather, that hooks it onto the deck.

And so that critical motion was what we needed to have in order to unlock the arm. And then, of course, we've now exercised the elbow as well, elevating the arm about 30 degrees above the horizon to start the unstow. Well, that's more great news. Before we get on to what's ahead for the spacecraft and the science, I read that you put a real powerhouse on Mars. Those big solar panels seem to be doing pretty well. Yeah, that's a little bonus record that we got. We sized those solar panels, of course, to be able to last all the way through a Martian

winter and then into the next summer so we can get our full Mars year on Mars. Plus, we needed to be able to survive whatever likely dust storm that Mars could throw at us. And the dust storm that just passed a few months ago, a few months before we landed, was probably the thickest dust storm in terms of the obscuration of the sun that we've measured at Mars since we started exploring. And that one has apparently ended Opportunity's mission, unfortunately. But that dust storm was one that's probably right on the edge. We probably would have been able to survive that one with these solar panels. And so we've sized them to make this a long lasting mission. And of course, the bonus is we've got the largest solar generator off the Earth, I think.

I haven't looked at what the generation capability was on Apollo, but certainly on Mars, it's the most juice that's ever been delivered. I think that's probably a pretty safe bet. And who knows, maybe you'll get one or two of those cleaning events that helped out Spirit and Opportunity so much. Yeah, we're sort of hoping that that's the case. We decided not to depend on that when we designed the solar panel. So we should be able to get through a whole year even without those cleaning events based on the amount of dust that settles out of the atmosphere. Those are what we're kind of counting on for the real long-range possibilities

for extending this mission into the future. Okay, so what is ahead? What's in the near term for InSight? We're heavily into our deployment phase right now. We're unstowing the arm, getting ready to take a bunch of pictures of what we call our workspace, the area that the arm can reach. pictures of what we call our workspace, the area that the arm can reach. We've had a few hiccups along the way, actually. We first had a little problem fine-tuning the radio between Mars and the Earth. The conditions on Mars affect the, especially the temperatures, affect the frequency. The frequency of our radio wandered a little bit, and we had to adjust, so we missed one of our downl links with that issue.

That's all fixed now. The next thing that happened was that we took an image right before we were finishing what we call the step two of our unstow. Because that image turned out to have the sun in one corner of it, the auto exposure routine in the camera actually timed out and that aborted the rest of that sequence. And so we're redoing that sequence right now, actually, it's been set up to the spacecraft and we should have the remainder of the arm and so process completed by tomorrow. But once we do that, we can start taking pictures of that workspace, putting together a stereo image set of that to be able to do our digital terrain model and start Mars forming our test where those instruments might go. And hopefully around Christmas time, we can start deploying the seismometer. Wow, that's pretty good. And I can't think of a mission that hasn't had at least a setback or two. And it sounds like these have been reasonably minor that they've certainly

have been overcome, which must be reassuring. Yeah, I mean, really, we're shaking out a brand new vehicle in a brand new environment. This is really typical. It's just fine-tuning, you know, how we operate, sort of learning the details of how it's going to adapt to the Martian environment. Once those seismometers, the SISE, S-E-I-S, instrument is down there on the ground, there are six of them, of course. They're so exquisitely sensitive. How hard is it going to be to pull science data out of all of the noise in the signal-to-noise ratio, I mean, from wind and temperature and so on, that you're going to have on Mars. I mean, I'm thinking of Troy Hudson telling us last week on stage at Caltech that even the overhead passage of that tiny moon Deimos will be detectable by the seismometers. That's right. I mean, the funny thing about seismology is that actually modern seismology is all about

processing noise and getting information from the noise. Because the noise is just one person's noise getting information from the noise. Because the noise is just one person's noise is another person's signal. It's kind of a truism in science. And so you have all this noise, and the noise is actually all coming from somewhere, okay? So it's coming from, you know, atmospheric turbulence. It might be coming from the temperature cycling of the surface. It could be coming from the gravitational pull of a tiny moon orbiting overhead. If you're trying to look at a Marsquake signal, you want to remove as much of that stuff from your data as possible. But on the other hand,

most of these noise sources actually have information on them. So for example, when Phobos goes overhead and it pulls up the surface of Mars by a little bit and then lets it go back down again as it goes away, the amount that it actually goes up and down depends on the details of the structure of the interior. And there's ways that we can interpret that in order to figure out the size and the density of the core. That signal is really weak, but we can look at it as Phobos goes overhead over and over and over again every six and a half hours. We can sort of keep on stacking up those signals, just adding one to the other and increasing that signal while the noise stays the same. And pretty soon, we have a pretty good determination of the flexing of Mars due to that tiny gravitational traction of Phobos.

So that's just one example of how we can use noise to get information about the interior. Meanwhile, you know, we've tried to shield the seismometer against as much of the environmental factors as possible. We put a wind and thermal shield over the top of it. We've encased the seismometer in sort of a double-walled thermal enclosure. And inside that, we have the vacuum enclosure that given us fits a couple of years ago. So we have sort of three levels of protection of the seismometer. But we can't shield it against things like a little pressure front goes through. It actually pushes down on the ground and makes a signal that way. So those things are just things that we have to measure

with other sensors on our spacecraft and try to mitigate the effect of that on the seismometer. So we've got a whole set of things to shield it. We have a whole set of things to measure the environment that's affecting it. And all that together was going to allow us to really delve down into the sort of the depths of the small displacement universe on Mars. Are you also looking forward to starting to take the red planet's interior temperature? Oh, absolutely. I mean, that's going to be a lot of fun, too. You know, it's going to be

both fun and a little bit nerve wracking. I mean, Troy was talking to me the other day about, we went through our seven minutes of terror, but pretty soon, you know, once we get the mole down on the surface, we're going to go through about seven weeks of anxiety, you know, every day, you know, going down a little bit further and hoping that we don't, you know, hit a rock or have some other kind of issue with the mole. So it's a little bit of a nail-biter, you know, once we get the mole in and get beneath the surface where we can't see what's going on, and of a nail biter, you know, once we get the mole in and get beneath a surface where we can't see what's going on and it's just going to, you know, do whatever it's going to do. So it's a little bit of slow motion terror, you know, it's coming up next spring.

I hope you get to set that record for the deepest hole drilled anywhere off of our own planet. We didn't say enough on last week's Planetary Radio about the international nature of this mission. Can you give us some examples of the global contributions? Well, this is really a global partnership. The main parts of our payload actually come from places outside the United States. The seismometer, which is the heart of our mission, is primarily built by the French, and it's financed by the French space agency, CNES. They partnered with several other partners. The Swiss have supplied the data acquisition electronics and the box containing all the instrument electronics for the seismometer.

Germany built the leveling system, the framework that holds a seismometer and has motorized legs that can level it on Mars. The British contributed three of the six sensors that are on the seismometer, the short-period sensors. And the United States actually contributed virtually all of the protection, thermal and wind protection, as well as the cabling that connects the seismometer to the spacecraft. And so the seismometer itself is an international collaboration. Plus we have the HB cube, the heat flow probe that is built primarily by Germany. The hammering mechanism was actually built in Poland, and the United States helped the Germans with a lot of the detailed design work, especially the shock mitigation mechanisms to keep the insides of the mole from shaking themselves to pieces. And so the payload has been built all across Europe and the United States. And we have scientists from all over the world on our science team as well. So once the data starts coming down,

the data is going to go streaming out to Europe, to Asia, Australia, as well as the United States, and scientists on the team are going to start pouring over the data. And then just months after we acquire it and start looking at it, we're putting all that data out onto the internet, available for anyone in the world to download and do research on themselves. And so I think, you know, both in terms of the input to this mission and in terms of its value and the availability, this is really a global mission. Yeah, I know a lot of scientists who can't wait to get their hands on that data. And we had one of them on stage with us last week, Caltech geophysicist Jennifer Jackson, who said that she's also looking forward to InSight helping us better understand our own planet, Earth. Is that true

for you too? Yeah, I mean, that's really what almost all the science that we're doing in the solar system comes down to is really understanding the Earth itself, how the Earth formed, where it came from, so to speak, how it evolved to where it is today, and where it kind of sits in the universe in terms of habitable planets, non-habitable planets, and so forth. And so Mars is just another laboratory, really another experiment on building a planet. And if we understand not just what it's like today, but how it got to where it is today, and we start using that information to inform our models of the Earth's formation and evolution, we can start really understanding how the Earth got to be where it is, how it got to be a habitable planet versus, you know, a hot hell like Venus or a cold, desolate place like Mars. What are the turning points? What are the tipping

points between, you know, going in one direction or another? And we're finding new connections all the time between what seem to be, you know, obscure details of the interior of the planet and some extremely important parameters in terms of habitability. You know, the interaction between the magnetic field of the Earth and, you know, the protection of its atmosphere from the solar wind erosion and the cycling of carbon through the mantle and back up into the atmosphere through volcanic venting. These are all things that look like they're really critical for maintaining a habitable surface on the Earth. It's really putting a bigger focus on geophysical research on the Earth.

And by extension, you know, the research on other planets and then informs us of what's going on on the Earth as well. Very exciting stuff and so much ahead of us, Bruce. I've just got one more for you. Is it true that you started thinking about a mission like this about 40 years ago? Oh, yeah. The thing is, you know, I get a lot of credit for, you know, making this mission happen. And I take that all with a little bit of salt because it was really obvious, even back in the 60s, that, you know, this kind of exploration of planetary interiors was an important thing. And that's why there were seismometers, heat flow probes, precision tracking on the Apollo landings on the moon,

exactly the same kind of payload that we have now. Hopefully, we have a little bit better technology now, 45, 50 years later. But that was clear back then. And when I was a graduate student, I saw the Viking missions go to Mars with a pair of seismometers we had high hopes for, which due to limitations that were placed on the instrument really didn't pan out for Viking. But, you know, as a geophysical graduate student in the mid-70s, you know, the failure of the Viking seismometers to give us data was a real disappointment.

And so I was thinking back then, as were a lot of my colleagues, be really great. You know, we needed to actually get another mission out there with a seismometer. And it still is the source of amazement to me that here 40 years later, I'm actually so deeply involved in doing it when I was waiting for someone else

to do it 40 years ago, but somehow it worked out a little bit differently. Well, I'm glad you stepped up. And Bruce, thank you on behalf of everybody who has been waiting for these instruments or instruments like them to reach the red planet. We're there. Best of continued success as we see them deployed and start to deliver science back home. Well, thank you very much, Matt. And I look forward to talking to you again on the show as well when that science starts to flow in.

We've been talking with Bruce Banner. He's a principal research scientist at the Jet Propulsion Lab, and he is the principal investigator for the InSight mission, now preparing to reveal the deep interior and much more of the history of Mars and maybe of our own planet as well. Time for What's Up on Planetary Radio. Bruce Betts is the chief scientist for the Planetary Society and does a lot of other stuff.

He also spends a lot of time looking at the night sky, and then he comes in every week and he tells us what he sees. So I'm hoping he'll do that for us now. Hi there. Hi. I saw light pollution and clouds. But there's more to look forward to. We've got great stuff in the sky this week. Let's start with the Geminids meteor shower peaking on December 13th and 14th. Best viewing will be after midnight once the moon is set, and it's often the best meteor shower of the year with 100 meteors per hour potentially

seen from a dark side. So the night of the 13th into the morning of the 14th. We also have planets you can look at while you're at it. In the evening sky, Saturn's getting awfully low, but you might pick it up low in the west after sunset. And then Mars still shining quite bright despite fading up in the south in the early evening. On December 14th, there will be a lovely combination of the moon next to Mars. In the morning, we've got Venus dominating in the east sky. Then coming up below it to the lower left is Mercury. And coming up a little bit later will be Jupiter. And looking further ahead, we've got December 21st. Jupiter and Mercury low in the east will be hanging out very close together in the pre-dawn sky.

But wait, if you're really inspired, there's a comet. Now, you probably won't see it with naked eye, although you might from a dark side, but pull out some binoculars, find a finder chart online, and look for comet 47P Wurtinen. It's not that hard. I should be able to pronounce it. It gets closest to Earth on December 16th. Again,

you're going to probably want binoculars or a telescope for this one, but it's out there, 46P Ortonen. Very cool. Maybe I'll take a look. Yeah. On to this week in space history. 1998, 20 years ago, the International Space Station as a multi-module space station was born when the Unity and Zarya modules were connected to each other this week. Further back in time, 1972 Apollo 17, the last of the Apollo missions to the moon landed on the moon.

We move on to random space fact. This is a little bit what I was sounding like when my cold was much worse than it is today. I have no excuse. Osiris-Rex, of course, getting to asteroid Bennu. Bennu was named using a contest that the Planetary Society held by Michael Puzio, at that time a nine-year-old. And it was because of the similarity he saw between Bennu, at the Planetary Society held by Michael Puzio, at that time a nine-year-old. And it was because of the similarity he saw between Bennu,

which the Egyptians depicted usually as a gray heron. Osiris-Rex, the touch-and-go sample mechanism, looked kind of like the long neck, and the solar panels looked kind of like wings, and that's why asteroid Bennu is named asteroid Bennu. Michael, who is now a high school freshman. We heard him early in the show during the interview that he did on Sunday on National Public Radio. Well, how appropriate. All right. We got an interesting contest here.

Yeah, apparently very easy, encouraging a lot of people to participate. What chemical elements were named after celestial bodies or the gods and goddesses for whom the bodies were named? I already know, but how do we do, Matt? You bad, bad boy. In the week following, maybe the biggest response we've ever gotten to the contest, we've had the smallest in a very long time. I try to mix it up. We had just enough to make this worthwhile. Random.org chose for us Timothy Myers, a first-time winner in Saratoga, California. He's got nine of these. Sirium, name for asteroid Ceres.

Helium for Helios, the Greek name for the sun. Mercury, not surprisingly named for Mercury. Neptunium, Neptune. Palladium, asteroid Pallas. Plutonium, Pluto. Selenium from Selene, the Greek name for the moon. Tellurium, this one feels a little trickier to me, from Tellus, the Latin name for Earth, and Uranium, of course, Uranus. Those are exactly the ones that Timothy Myers provided.

So, Timothy, you are the winner. He didn't add the 10th one that Howard Medlock in Lubbock, Texas, proposed. He said this is, for those with imaginary friends, Krypton. Indeed. Timothy, you have won a Planetary Radio t-shirt from the Planetary Society Chop Shop Store. You can see it at chopshopstore.com. A 200-point itelescope.net account to do astronomy all over the world on that terrific network of

scopes. And yes, you can donate that. And a copy of Jeff Bennett's Max Goes to Mars, which would have been great for nine-year-old Michael Puzio if he was still nine years old. But it's really a very good book. And Jeff is a very good guy. And I want to mention on his behalf, because he does all this stuff for free, over the next couple of years, Jeff Bennett is going to be, he's offering a free visit to one community per month, schools, communities, whatever, colleges. And he is a terrific speaker about science, about planetary science, about climate change. And it's truly free. I think he's crazy, of course. But if you want to get in on this, you can go to JeffreyBennett.com slash visit. JeffreyBennett.com slash visit.

So, Jeff, good on you. We've got some other good stuff here, as you might imagine. Adam Ladak, or Ladak in Toronto. He says, is it celestial fate or just science? Selenium, the Greek name for the moon, discovered in 1817, sits right above the previously discovered tellurium named after the Earth on the periodic table of elements. I bet you didn't know that. I did not know that. Random element facts. And finally, from our friend Torsten Zimmer in Germany, these are the only ones of which the news has come to Harvard,

and there may be many others, but they haven't been discovered. I hope we have some Tom Lehrer fans out there other than Torsten and myself. That clears us out for this time. We're ready for the next contest. All right. Drive the quantum mechanical state of the... Oh, no, you said I was supposed to do something easier. All right. How about this? We talked about Comet 46P Wurtzmann. What spacecraft was going to visit Comet 46P Wurtzmann? Go to

planetary.org slash radio contest. You have until the 12th, December 12th at 8 a.m. Pacific time to get us the answer for this one. And we will award somebody a Planetary Radio t-shirt, a 200-point itelescope.net account. And get this directly from our friends at National Geographic. It is the National Geographic Space Atlas, Mapping the Universe and Beyond. This is the second edition. It is brand new. I cannot imagine a more gorgeous book, as you might expect from National Geographic, to take you on a tour of the cosmos. But wait, there's more. Oh, no. It's a two-book set. They're also including, this is the almanac from National Geographic,

which you are going to want to leave in the bathroom, enough said. It is really fun. It's not just space stuff. It's an almanac. What can I say? It's also beautiful, as you would expect. And I measured, this is about seven pounds worth of books. So the postage is going to cost the Planetary Society a bit, but nothing's too good

for you, our winner of this latest contest. We'll be deducting that from someone's pay. Yeah, let me guess. I think we're done. All right, everybody, go out there, look up at the night sky, and think about the reindeer comet and whether his tail always points away from the sun. Thank you, and good night. I'm more interested in whether his nose glows red from the heat of the sun. That's Bruce Betts. He's the chief scientist for the Planetary Society, and he does join us every week here for What's Up. Or whether he gives off gas when he heats up. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its proud members.

Mary Liz Bender is our associate producer. Josh Doyle composed our theme, which was arranged and performed by Peter Schlosser. I'm at PlanRad on Twitter, but you can call me Matt Kaplan at Astro.