Planetary Radio • May 12, 2021

Defenders of Earth on Planetary Radio

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Bruce Betts

Chief Scientist / LightSail Program Manager for The Planetary Society

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Nancy Chabot

Planetary Chief Scientist at Johns Hopkins Applied Physics Lab, and Coordination Lead for DART

Paul chodas portrait

Paul Chodas

Manager, NASA NEO Program Office for Jet Propulsion Laboratory

Gerhard drolshagen portrait

Gerhard Drolshagen

Chair of the Space Mission Planning Advisory Group, University of Oldenburg

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Kelly Fast

Near-Earth Object Observations Program Manager for NASA Planetary Defense Coordination Office

Masaki fujimoto portrait

Masaki Fujimoto

Deputy Director General of JAXA's Institute of Space and Astronautical Science (ISAS)

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Mat Kaplan

Senior Communications Adviser and former Host of Planetary Radio for The Planetary Society

The 2021 Planetary Defense Conference brought together the leading scientists, policymakers and other experts who are working to protect our planet from near-Earth objects (NEOs). The Planetary Society welcomed six of these heroes to a special virtual gathering in late April. You’ll hear their progress reports on this week’s show. One is our own Bruce Betts! He’ll stick around for a NEO-packed edition of What’s Up.

DART approaches the Didymos system
DART approaches the Didymos system Image: NASA / JHUAPL
Hayabusa2 Sample Return Capsule Recovery
Hayabusa2 Sample Return Capsule Recovery Hayabusa2 team members recovered the intact sample return capsule from the Australian outback on 6 December 2020. Each particle of material from asteroid Ryugu is now being cataloged.Image: JAXA
NEO Surveyor Artist's Concept
NEO Surveyor Artist's Concept This artist's concept of NASA's Near-Earth Object Surveillance Mission shows the space telescope in front of a star field captured by the WISE telescope.Image: NASA/JPL-Caltech/The Planetary Society
Didymos Size Comparison
Didymos Size Comparison The DART target Didymos B has a diameter of ~160 meters and is about half the height of the Eiffel Tower. Didymos A, the primary member of the binary system, is ~780 meters in diameter.Image: JHUAPL

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Earthlings vs Asteroids: What's the Score? A special virtual event held on April 29, 2021, taking a look at the state of humanity’s planetary defense efforts.

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Trivia Contest

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A Planetary Society r-r-r-rubber asteroid!

This week's question:

Name all the near-Earth asteroids that spacecraft have touched.

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Complete the contest entry form at or write to us at [email protected] no later than Wednesday, May 19th at 8am Pacific Time. Be sure to include your name and mailing address.

Last week's question:

On Michael Collins’ second EVA, what did he collect from the Agena target vehicle AND what unrelated item did he lose during that EVA?


The winner will be revealed next week.

Question from the April 28, 2021 space trivia contest:

Who was the asteroid Kaplan named after?


Asteroid 1987 Kaplan was named in honor of Russian astronomer Samuil Aronovich Kaplan by its discoverer, Pelageya Shajn. (You weren’t thinking of someone else, were you?)


Mat Kaplan: Six heroes of Planetary Defense, this week on Planetary Radio. Welcome, I'm Mat Kaplan of The Planetary Society, with more of the human adventure across our solar system and beyond. Are we Making Progress Toward Avoiding the Fate of the Dinosaurs? That was the theme, when I welcomed an international group of experts for the only public event at this year's Planetary Defense conference. You'll hear they're very encouraging reports on today's show, and we'll talk about what's ahead, including the first mission to test asteroid deflection.

Mat Kaplan: One of those experts is our own Bruce Betts, he'll stay with us for a planetary defense centered edition of What's Up? Including the return of The Rubber Asteroid of Doom. I'm very grateful to everyone who took a moment to rate and review Planetary Radio in Apple Podcasts, I'm even more grateful to all of you who subscribed. No worries, if you haven't gotten around to it, the cosmos and I are patient. Even giant planets have reason to worry about asteroid and comet impacts. Take a look at what Comet Shoemaker-Levy 9, did to Jupiter in 1994, ouch.

Mat Kaplan: You'll find the image at top of the May, 7 edition of the Down Lake. Great space headlines too though, Mars Helicopter ingenuity has now completed a fifth flight across the red planet. I hope you'll join us for next week show when I'll welcome back ingenuity project manager, Mimi Aung. And there's much more than news at Our friends at Explore Mars have scheduled the very first Mars Innovation Forum for May 25 to 27, and they've lined up a terrific collection of Red Planet All Stars, for this virtual event.

Mat Kaplan: I'll be moderating a session called Building and Creating on Mars, but I look forward to hearing all the great conversations. You can check it out and register at The four day 2021 Planetary Defense Conference ended on April 30th, like so many other regular gatherings this year, participants had to meet online. This limitation doesn't seem to have limited the impressive agenda, or the presentations by scores of leaders from around the world. As you'll hear, it once again, included a carefully designed exercise, a simulation of an encounter with an asteroid that was as exciting as any movie, and far more instructive.

Mat Kaplan: The Planetary Society was, once again, a primary sponsor of the PDC. What you're about to hear is almost all of the hour we were given to share the excitement in a live webinar. Each of our six outstanding panelists had a great story to tell, you'll hear them introduced as we go forward, so I'll stop wasting your time and take you directly to Thursday, April 29th, and program we called Earth Leans Versus Asteroids, What's the Score. Good morning, good afternoon, good evening, wherever you are around our beautiful planet.

Mat Kaplan: I'm Mat Kaplan of The Planetary Society, where I host our public radio series and podcast Planetary Radio. We come to you today as part of the International Astronautical Academy's 2021 Planetary Defense Conference. It is the seventh biannual gathering of experts and policy makers from all over our pale blue dot. We'll hear from six of these passionate defenders of Earth, think of this as a status report. By the end of the hour, we hope you'll have a better feel for what's being done to make sure that humanity doesn't go the way of the dinosaurs.

Mat Kaplan: Kelly Fast, is the Program Manager for Near Earth Object Observations Programs in NASA's Planetary Defense Coordination Office, where she works with the Planetary Defense Officer at NASA, Lindley Johnson, welcome Kelly.

Kelly Fast: Hi Mat, thank you.

Mat Kaplan: What is the first order of business, if we want to learn how to defend our planet from big rocks, that might come our way?

Kelly Fast: Well, the first order of business for Planetary Defense is to find the near-Earth asteroids and the near-Earth objects, and the asteroids or comets that come into Earth's neighborhood and to figure out where they've been and where they're going to be in the future. If we don't know that something could pose an impact threat, and we can't take all of these other steps that you're going to hear about today also. So the first order of business is to find them.

Mat Kaplan: No doubt. Like our other panelists, you have some slides that we're going to zip through, beginning with this impressive collection of telescopes. Do they begin to give us an idea of what's being done at NASA to define the NEOs that we don't know about yet?

Kelly Fast: Oh, absolutely. This is the bread and butter of Planetary Defense, just that surveying the skies, looking for that moving point of light against the stars. And so these telescopes provided by a number of institutions that are funded through NASA program, are doing this every night, surveying the skies, looking for objects, or looking for natural objects that might not already be in the catalog. And these telescopes are provided by the University of Hawaii, with the Pan-STARRS survey, and the University of Arizona Catalina Sky Survey.

Kelly Fast: They're kind of the most productive of the surveys being funded by NASA right now, producing most of the discoveries. But also complimenting them, are the Atlas telescopes from the University of Hawaii. Also a nice inter-agency coordination here with the US Space Force on their Space Surveillance Telescope, and pulling asteroids out of the images that they take at night. Finally, even repurposing a telescope that was developed for another purpose. NEOWISE is the repurposed WISE space telescope, that is now full time surveying for asteroids. Wasn't designed to do that, but it's kind of a good Pathfinder on the way to how to do this properly from space.

Kelly Fast: And it's producing a lot of characterization information, size information about asteroids in the catalog. And then there are also many other observatories funded by the program involved, in following up these discoveries and trying to make sure there's enough information to calculate the orbits, to know where these objects are going to be in the future. Congress gave NASA a goal to find 90% of the near-Earth asteroids that are 140 meters and larger in size. Now we want to find all of them that our telescopes can detect, but this is the size range that would really pose a regional threat, should an object of that size impact Earth. So it's kind of a good benchmark to go after.

Kelly Fast: And the folks who do all the modeling are able to estimate that there's probably about 25,000 of those objects out there, we're only about 40% of the way through, but still plugging away every night. At the current discovery rate, it is going to take more than 30 years to complete the survey, but there are efforts to look at next generation telescopes to speed this up. But again, those telescopes I just showed you, they're just plugging away every night to this path finding that I mentioned, like from the NEOWISE telescope.

Kelly Fast: And also from a number of studies done with the community, including with the National Academy of Sciences, all of them point toward the need to put a telescope in space and that it should have infrared capability, in order to be able to yield size information and also to get these discoveries of asteroids that might be very dark in color, and harder to pick up from telescopes on the ground, that are looking in the optical and what our eyes can see. And something might be very large, but if it's very dark in color, it might be very faint. And ultimately to speed up to speed up those discoveries of 140 meters and larger near-Earth asteroids.

Kelly Fast: And also any asteroids that are picked up by the survey, add those to the catalog and then be able to retire risk from them and hopefully not, but if there is something that poses an impact threat to Earth, to discover it many, many years ahead of time, decades ahead of time. Right now in the Planetary Defense Conference we are dealing with an asteroid scenario of a fictional asteroid, that was discovered only six months prior to impact and wrestling with those issues. We don't want to find ourselves in that type of a scenario. And so there are many reasons for then looking at, what is the best way to speed up the survey and to make sure that we have lots of time. And so this is what NASA is working on.

Mat Kaplan: And we're going to hear more about that exercise from Paul Chodas, who is the evil genius out to destroy the Earth simulated fashion in that exercise. We're also going to hear about work that is being done all over the planet from some of our other panelists, but what about, worldwide collaborative efforts to track and characterize NEOs?

Kelly Fast: Right. Our Planetary Defense Officer likes to say that, "Planetary defense is a team sport, and it does take a worldwide effort." There actually is that underway, the UN recommended a collaboration, the International Asteroid Warning Network. This is a collaboration of observatories, and independent astronomers, and space institutes, and orbit calculators worldwide to bring their capabilities to bear on this near-Earth asteroid planetary defense issue.

Kelly Fast: And so there's a lot of contribution from these different institutions and observatories, in terms of following up the discoveries of asteroids, getting more observations to be able to determine their orbits, to determine where they're going to be in the future, doing modeling of what the population might be, or what impact effects might be. All of that coming together as part of an international collaboration, everybody working with their own institutions, everybody doing what they're already doing, but getting these communication channels in place. So that if there ever is any sort of impact threat that needs to be addressed, that will be in place.

Kelly Fast: And this group, the International Asteroid Warning Network, also conducts its own coordinated observation campaigns, sometimes treating them as planetary defense exercises in their own little scenarios, in order to exercise these capabilities and these communication channels. And in fact, with the Asteroid Apophis, there was a recent observing campaign that's just wrapping up, with Apophis, where astronomers around the world were observing it to try to characterize it at this last opportunity, before its 2029 close approach, so a very good collaboration.

Mat Kaplan: Speaking of international efforts, Gerhard Drolshagen, chairs the Space Mission Planning Advisory Group. formerly of the European Space Agency, Gerhard now joins us from the University of Oldenburg. Welcome Gerhard.

Gerhard Drolshagen: We heard it's important to find objects that could pose a threat to Earth, but then it's the next question, what could you do? And of course, one idea is to just move them out of the way, to prevent a potential collision with Earth. And that's why is this international group, you mentioned Space Mission Planning Advisory Group, has been established because any impact risk is global and it needed an international effort to try to do something. And this group gets together and discusses what can be done with a space mission if the object is real big and real threatening, to avoid an impact

Mat Kaplan: We've learned that not all asteroids are alike, we visited several?

Gerhard Drolshagen: That is correct. I mean, it's also realized, and we get this information from the colleagues who find the object and characterize them, that each object seems to be different. They have different sizes, obviously from very small to real big kilometer sizes, and also they can have different shapes. And in addition, what is not so obvious, to be recognized, they can have very different composition. So it turns out that those three here, which have all been visited by spacecraft, Itokawa on the left, it's about 500 meters in size. And then you have the Ryugu and Bennu, and these are all rubble piles.

Gerhard Drolshagen: So they are not solid rocks that really composed of different pieces of small rocks and dust. And if you want to deflect an object, with whatever method, then you need to know what is it made of. And there's a whole range of different proposals, what one could do to deflect such an object. And therefore it's very important to know what they are made of, and it helps, I mean, those three objects that you can see here were visited by a spacecraft, but this was for scientific reasons, just to understand what they are made of and it was not the idea to test any deflection methods. So some samples where we turned from those objects, and we learn about them. And this is very important if eventually one of these objects comes close and we have to think about deflecting it in reality.

Mat Kaplan: Fairly soon now, not too many years from now, we will finally be making a closeup visit to one of those most dangerous kinds of asteroids, those iron-nickel or nickel-iron asteroids, that's in an upcoming mission. We've heard, speaking to visiting asteroids, from Kelly, about observing NEOs, near-Earth objects from a distance, whether it's from Earth's surface or our powerful space telescopes, should we also be prepared to send fast spacecraft, to examine the threatening NEOs from up-close, maybe in fly bys?

Gerhard Drolshagen: Yes, that is certainly something which is highly desirable. First of all, by such fast missions, which could be done by a very small spacecraft, they are very powerful these days. You can learn about them, and you can get some information on the size. Normally you see a bit a dot of light, but you don't know, is it a very bright object or not too big? If you see how bright is the dot of light, or is it a dark object and it could be much, much larger. And if you want really to deflect it, you have to know what is its real size. So it is very useful to perhaps send a small spacecraft to better characterize it.

Gerhard Drolshagen: It might also help to get the real orbit, and if those people like Kelly, tell us how it could hit Earth, normally you don't know for sure. So if you fly there, it could help get better information on the orbit. Of course, you might also obtain this from ground-based telescopes and radar, but it might have to fly there. I think it's something that could be done fairly easily, and I'm sure in the future, several of these missions will be realized. Several are in planning and we can learn a lot. And this could be done on a very short notice, if a new interesting object or dangerous object is been discovered.

Mat Kaplan: Tell us about Hera?

Gerhard Drolshagen: Well, I guess we hear more about these missions, the DART Hera mission, but it's already one good example of an international corporation. Because that will be built by NASA, it's been built right now, and it should test, if you just hit the object, could you push it away, and how much could you push it away, and can you hit it to where you like? And then ESA, is buildings the Hera spacecraft that comes a little bit later, and that will characterize what has happened. And you can see how big is a crater, and what was really the composition of this object, if you just bang it very fast, you do not know is that will really help the test, and sees the effects such an impact had.

Gerhard Drolshagen: I mean, by the way such, what we call a kinetic impact that is the idea, you hit it as fast as you can with a spacecraft as big as you can, and give it a little push. In any case, the spacecraft will be much, much smaller than the object will be, but if you do it soon enough, then you can push the object away this times that it will miss Earth. You don't want to destroy it, you don't want to change the object completely, but as we want to test the effects, and this can be done as this Hera spacecraft, which comes after the impact event to see what really has happened.

Gerhard Drolshagen: You have to think carefully what can be done, and when do you do it, and also to calculate how much push is needed in all that to deflect such objects. Perhaps one little comparison, if you have two cars on the road crossing, you want to avoid them to collide and you don't have to move the roads, which would be the orbits of these objects. You just have to make sure that the two cars are not there at the same time. And the best way we talk about asteroids is either to push one of the objects forward, or to slow it down. You cannot really do this with Earth, because Earth is much too big.

Gerhard Drolshagen: But such an object, if you push it a little bit, that it's crosses this road, it passes the road crossing a bit sooner or a bit late as in the other object, and you avoid the collision. And that is the main mechanism, and it shows it's not so easy if you look at the objects, and the massive scale they have.

Mat Kaplan: So far it's been asteroids, asteroids, asteroids. What about a comet, a sneaky comet that we might not get as much of a chance to track for very long before it heads our way?

Gerhard Drolshagen: Yes, you're right. I mean, comets are a real risk. Fortunately, there are far less comets which could hit Earth than there are asteroids, which we can find easily. But if a real big comet, several kilometers in size, they tend to be big. And we only discover it on very short notice, it comes from way out, from a far distant location and you can only see it when it starts to devolve the tail, and so it's really a difficult thing. I would say, this is a next step we have to deal with. First, we try to deal with the more dangerous and more numerous asteroids, comets are a real threat, but right now it's difficult to deal with them. But we will work with them.

Mat Kaplan: Thanks, Gerhard. let's go now to Paul Chodas. Paul is manager of the Near Earth Object Program Office, he's based at the Jet Propulsion Lab, very close to where I am right now at Planetary Society Headquarters. Thanks for joining us, Paul.

Paul Chodas: [crosstalk 00:18:34] Thanks for having me.

Mat Kaplan: You're very welcome. Glad you're here. Let's go to your first slide, to how many NEOs are we keeping track of?

Paul Chodas: There are increasing numbers, 25,000 and more, and these are the real orbits of some of them. We're finding about 2,500 of these NEOs every year now, so the observatories that Kelly showed at the beginning, are very productive. But the question then is, do any of these pose a threat? So the group I work in CNEOS at JPL, is charged with the idea of figuring out what the orbits are of these asteroids and whether or not they have a chance of impacting NEOs, so We do an impact assessment on each one of this.

Mat Kaplan: That's an award-winning NASA acronym, CNEOS, the Center for NEO Studies. Here's the CNEO's website, which I think you're hoping lots of people will visit.

Paul Chodas: Yes. We are kind of the central repository of the orbit information for NASA's program. We do the calculations of the orbits, we have lots of tables and data on our website, you can go to our website and get predictions of where things will be, close approaches, yes. Asteroids become observable when they get near the Earth, and so we often see them coming in from the night-side, and many of them are very small, but some of them will be making close approaches, so we keep track of all the close approaches and update this continually. So we often see news items, I know on my phone, I see news items about, "Upcoming close approach." And, "NASA warns about a close approach."

Paul Chodas: Now, these asteroids are not heading for the Earth. I mean, sorry, they're not heading for an impact. They're going to come close, the asteroids on our close approach list, very few of them have any chance of impacting NEOs near us. So that's one thing that makes our site worth checking. We have 9,600 that are larger than 140 meters, and about 900 that are larger than one kilometer in size. So you see the discovery rate with NASA's funding of all of these telescopes has just been growing exponentially.

Mat Kaplan: So the good news there, right? For the most dangerous of these, the ones that are bigger than a kilometer, that red line down at the bottom, pretty flat nowadays, that's a success story, Isn't it?

Paul Chodas: It sure is. We think we found all about 95% of the population of the large ones, larger than one kilometer in size. And those are the ones that could result in a global catastrophe if they should hit, so we have kind of retired that risk. Essentially, there are only a few left and the odds that any of those will hit the Earth in the next hundred years that are extremely thin. We'll keep looking for all of these asteroids, of course, but the larger ones are pretty well taken care of. And now we're focusing on the orange line, and getting to the 140 meter in size, and as Kelly said, our goal is to find 90% of that population.

Mat Kaplan: Great goal.

Paul Chodas: Then the question is what type of event would occur if an asteroid of that size should hit the Earth? So the little ones produce bolides or superbolides, really bright meteors, but as you go to larger and larger sizes, you air burst, you get local devastation, and then in the orange region, you start getting regional, continental, to a little below global size damage, and then the green area is the larger ones that I said earlier, that we have already found 95% of.

Paul Chodas: Bolides happen about once a year, the five meter objects are pretty common, but the number of all NEO down as you go to larger and larger sizes. So for example, Chelyabinska size object is a superbolide or major airburst, somewhere in that area, which is basically a hundred years between impacts of that size. And as you go to the orange area, Regional Scale Devastation, a 140 meters sizes, and we're talking about thousands, tens of thousands of years on average between the impacts. Now that doesn't mean it can't happen next year or in the next decade, but the odds are against it.

Paul Chodas: For those of the audience who are interested in learning how to deflect an asteroid, we've loaded a realistic simulation onto our website. These are hypothetical asteroids that are headed for the Earth, and you are given the opportunity, having your own launch vehicle, and you specify when you'd like to deflect this asteroid in terms of years before impact. And you say when you want to launch your deflector, and this is an example of a kinetic impactor defense mechanism. And you can actually test the real physics on simulated asteroids, and as you devise your emissions, you can move that green dot, the current trajectory of the asteroid, you can move it so that it will miss the Earth.

Mat Kaplan: Your Personal opportunity to save the Earth. For those of us who are old enough to remember the game Asteroids, this is a pretty significant upgrade, I would say. Just really one more thing that you have to tell us about, even though the Planetary Defense Conference is virtual this year, it still has my favorite part of the conference every year. It is the Planetary Defense Conference exercise, which as I said, you are sort of the mastermind of, tell us just a little bit about this?

Paul Chodas: Yeah. I've been nicknamed the Threat Master in previous years, I devise a hypothetical case with a certain specified warning. In this case, we had six months between the time the asteroid was discovered and the time when it could hit, and we go through the question of what would we know when? And then we kind of inform the decision-makers of what the uncertainty levels are. So there's a lot of talk about probabilities of this and regions of possible impact, and this example is from our exercise where the region of possible impact covers central Europe, in this case.

Paul Chodas: So then we would present this image to decision-makers and they would consider, "Well, what would we do, is mitigation possible or are space missions possible? And what about the disaster management, how would you handle this situation?" Now in this case, it was many months before impacts, but the uncertainties are very difficult to deal with in decision-making. And as the impact got closer and closer, this region shrank,[inaudible 00:25:00], but then of course there's less time to react.

Mat Kaplan: I cannot tell you how much fun to be in the room when this happens, face to face, and listen to people, who even though they know it's an exercise and they're reminded on every slide that shows up on the big screen, how tense, how anxious the audience or the participants become as this takes place. I can't wait for the next one of these hopefully face to face in a couple of years. Thank you, Paul. Much more of our public event at the 2021 Planetary Defense Conferences ahead, including great questions we took from the online audience and a report on the upcoming DART, our Double Asteroid Redirection Test mission.

Mat Kaplan: Where did we come from, are we alone in the cosmos? These are the questions that the core of our existence. And the secrets of the universe are out there, waiting to be discovered, but to find them, we have to go into space, we have to explore. This endeavor unites us, space exploration truly brings out the best in us, encouraging people from all walks of life, to work together, to achieve a common goal, to know the cosmos and our place the... This is why The Planetary Society exists, our mission is to give you the power to advance space science and exploration. With your support, we sponsor innovative space technologies, inspire curious minds and advocate for our future in space. We are The Planetary Society. Join us.

Mat Kaplan: We are now honored to welcome Masaki Fujimoto. Masaki, is Deputy Director General of the Japanese apace agencies's Institute of Space and Astronautical Science. He has joined us from Japan where, Masaki, I believe it is just past midnight. Thank you for staying up so late to join us.

Masaki Fujimoto: My pleasure. Thank you.

Mat Kaplan: Congratulations on the recent magnificent success of Hayabusa2. JAXA's second spacecraft to return pristine asteroid material to eager scientists on Earth. Where were you when that sample return capsule streak through the sky on just the 5th of December, last year?

Masaki Fujimoto: Yes, I was in Woomera, where the capsule landed. But even though I was in the place where the capsule landed, I was staring into my PC screen, when you guys were enjoying the fireball running across the sky.

Mat Kaplan: Well, I've only seen the video, but it's pretty impressive. But you were there when the capsule was found in the desert, and that precious sample was carried back to a lab.

Masaki Fujimoto: Yes, I was in the headquarters of the operation team, I didn't witness everything, but I was involved in all the procedures, and after landing it took only 57 hours before we brought the sample back to our curation facility. And then a few days later, we opened up the capsule to find the 5.4 grams of samples, 55 times more than the minimum requirement. So it was a big success, I'm really proud to be a part of the team.

Mat Kaplan: As you should be, you and the entire team. And as you know, we've covered this on Planetary Radio, as well. Those samples, I don't know if they're being distributed yet, but eventually, those are going to go to labs all over the world, aren't they?

Masaki Fujimoto: Yes. So now we are performing the initial curation until June this year, and then for one year, we will perform the initial analysis, a prenup preliminary examination, so that we can create a catalog. Scientist's all over the world we'll understand the science size potential of the samples, and then starting next summer, we will be distributing the sample to all the scientists interested in analyzing the samples. So they will submit the proposal to us, and then there will be a whole process, and a selected scientists will have the opportunity.

Mat Kaplan: And I know how closely you'll cooperate and collaborating with the OSIRIS-REx team, which I believe is returning it sample from Bennu in 2023, if I remember correctly?

Masaki Fujimoto: Yes.

Mat Kaplan: Hayabusa2, of course, your spacecraft was delivering wonderful science long before that sample capsule made it home, can you briefly recap, highlight the work that the spacecraft was doing when it was up close and personal with a Ryugu?

Masaki Fujimoto: Yes. So, it was performing close proximity operation for one and a half year, and during that one and a half year... Well, first of all, when we got to Ryugu, we were so shocked by it's unfriendly surface. It's a sample [inaudible 00:29:55], so we have to land on the surface, but when we got there, every way on the surface is so rough. So we need to change the way we land on the surface, so we developed a new way of landing on the surface and getting the samples. We eventually managed to invent it, and made patch down twice, and the second touchdown was after the impact experiment, which excavated subsurface materials to the surface.

Masaki Fujimoto: We would deploy a impactor and let it reformed itself into a bullet and hit the surface, and make the artificial crater. So this is the closest relevance that this mission has to the [inaudible 00:30:34], I think. And after deploying the impactor, that main spacecraft itself will evacuate because you don't want to hit the debris from the impact excrement, to the spacecraft in a dangerous situation. So instead of the main spacecraft, we deploy the small detached camera and what we are witnessing here is the crater formation process under the micro gravity.

Masaki Fujimoto: And we are learning a lot about the crater formation mechanisms, and also also this impact experiments enabled the sub service material to come up on the surface, from which we grabbed the samples.

Mat Kaplan: Just amazing footage. As stunning as these pictures, we're now seeing of a helicopter flying on Mars, this is just amazing to see a human-made crater forming on Asteroid Ryugu. Since this was an impact, what it makes me think of, of course, is the role of Planetary Defense in the Hayabusa2 mission. Was this a major component of the mission?

Masaki Fujimoto: Well it's yes and no. We do leak some part of the asteroid exploration program of humanity in a sense. Playing some role in planetal defense, is almost a duty. So this impact the experiment, has some flavor of it, but what we also learned from the exploration of Ryugu is what's the best way to characterize the surface physical condition of a small body. And from my experience at Ryugu we learned that thermal infrared camera is one of the best instrument to characterize the surface condition, and that's why we are participating ESA's Hara mission, which was described in the previous talk.

Masaki Fujimoto: We are providing a thermal infrared camera so that the Hara mission will image the surface after the impact experiment by the US component, and then a camera should be one of the key instruments to characterize what the experiment was like as a whole.

Mat Kaplan: All right, something else to look forward to in the Hera mission coming up along with everything else that is going to be happening in the next few years. One of the biggest things that will be happening is the DART mission, which we've already mentioned. Nancy Chabot, is coordination lead for the Double Asteroid Redirection Test, DART, at the Johns Hopkins University Applied Physics Lab.

Nancy Chabot: So, as we talked about, DART is a NASA mission to demonstrate this kinetic impactor technology. And what that means is pretty simply, we're going to launch a spacecraft and we're going to target a small asteroid, and slammed the spacecraft into it. And what this is going to do, is it's going to give that asteroid that little nudge that we talked about already. Just sort of adds up to a change in the asteroids future path, and deflect it, so this is as a mission to demonstrate this kinetic impactor technology to deflect an asteroid. DART stands for the Double Asteroid Redirection Test. The T is for test, very important.

Nancy Chabot: This is just a test, it's the first step. This is not an asteroid that's a threat to hit the Earth, or on a path to hit the Earth. We're taking this first test step in order to do this technology. Before I go too much further, I really want to say too, that DART is a team, so I'm really happy to be here today and talk about DART and share DART, but we have hundreds of people at work at APL on this right now. We also have our partner institutions, which are bringing other, we have scientists around the world who are participating in to make this mission a reality in this success. So it really does take this international collaboration and hundreds of people working to make a mission like this, on a path to do this first test.

Nancy Chabot: What I want to say too, is that this is really the ideal target to do this first test, is this Didymos system. So the Double Asteroid Redirection Test goes to a double asteroid system, and that's what you're seeing here. So there's the big asteroid Didymos then Dimorphos, the smaller asteroid, goes around Didymos every 11 hours and 55 minutes, like clockwork. And we know this because telescopes on the Earth have been observing it for years. And so we know this very precisely from all of these measurements that have been done by the Earth based telescopes.

Nancy Chabot: And so what's going to happen is the DART spacecraft's going to come screaming in, actually 6.6 kilometers per second, 15,000 miles per hour, slam into Dimorphos. A few days before that LICIACube, which is the Light Italian Cubesat for Imaging of Asteroids contributed by the Italian Space Agency. We'll get kicked off, and LICIACube will get some spectacular images of this impact event from DART. And then it'll make a closest approach by the asteroid, about three minutes later, and then just continue speeding on its way. But now LICIACube is long gone, the DART spacecraft is definitely fully destroyed, so how are we going to know how much we deflected this asteroid?

Nancy Chabot: And that's when the Earth based telescopes come back in to play this really key role. And because this is a binary asteroid system, they can measure what that period is now. And we think we're going to change it by about 10 minutes, so maybe more like 11 hours and 45 minutes. But we don't know, actually, that's why we need to do this test on a real asteroid out in space. And then Hara, like we heard about, is going to come by in 2026 and have all this great characterization to really bring together, and we can gather the most information possible about this kinetic impactor technology experiments.

Mat Kaplan: So exciting to think that we are actually nearing the point where we will, for the first time, see if we have the capability to deflect an asteroid.

Nancy Chabot: And I really just want to say that, going back to this team theory, it's been a challenging year in lots of ways, but yet this work has continued. And procedures on top of procedures, and it really is a testament to how much people believe in this project and how dedicated everybody is. Some of the things that'll happen is the rollout solar rays they are going to get put onto it. The DRACO camera, which is going to be used to help target the asteroid is going to get put onto this in the next few months. And this is all to prepare the mission, to be ready to do this kinetic impactor technology demonstration, ready to launch in November of this year.

Nancy Chabot: So it's not very far off, Space X, Falcon 9 rocket from Vandenberg in California, and, we're really excited to be on track for that.

Mat Kaplan: Fantastic. Thank you, Nancy. You know, our last panelist is my partner in the What's Up? Segment of Planetary Radio, for over 18 years now. He is the Chief Scientist for The Planetary Society, and the Program Manager for our LightSail 2 CubeSat that is still up there catching some rays, Welcome Bruce Betts.

Bruce Betts: Thank you, Mat. Good to see as usual.

Mat Kaplan: Tell us about the big announcement that you made on behalf of The Planetary Society this week, using the PDC as the background?

Bruce Betts: We've announced another round of our Gene Shoemaker Near-Earth Object grant program, which funds astronomers, amateur and professional around the world, that you can see a display of where we've funded over the last 24 years. And we fund them to upgrade their observatories in whether it be a new camera, or re aluminizing a mirror, or making them more robotically controlled so they can get more data. And although now most of the professional surveys as Kelly noted, discover most of the Near-Earth Objects, there's still a need for lots of observations from lots of places, for followup observations that if a position on the sky, so that people like Paul Chodas, can calculate Orbitz and figure out whether it's going to hit Earth.

Bruce Betts: And then also characterization of these over time and observing them, things like light curves, brightness with time, so you can figure out their spin rate, or whether one asteroid is actually two, like DART we'll go explore a binary system. And also what they're made of, things that you'll need to know if you are going to have to deflect them at some point. So we have just announced an open call for proposals, they're due at the end of July, and you can find out more at

Mat Kaplan: Also something brand new from The Planetary Society, what are the new STEP grants?

Bruce Betts: Yeah, we just started a new grants program, open international call for proposals, pre-proposals due May 26 called STEP, Science and Technology Empowered by the Public. Because we are a member organization, these things only happen because of members and donors to our program. And now we're able to offer some larger grants through a competitive process across all sorts of space exploration and technology areas. But one of our three core enterprises is planetary defense, defending from asteroids. So hopefully we'll get some things that don't fit into the Shoemaker NEO grants, we'll find out that we've got some good proposals to the new STEP grants program.

Mat Kaplan: You and our other colleagues of the society, we got to have a good time coming up with this acronym. We only usually get to have the fun everybody else does coming up with clever acronyms, like the rest of you on the panel. [crosstalk 00:39:43]-

Bruce Betts: [crosstalk 00:39:43] make acronyms for everything, but they get rejected periodically.

Mat Kaplan: True. Yeah, rightfully so. There's so much more that the society does plug, plug in ways to help us improve the understanding of, and the support for planetary defense?

Bruce Betts: We've got a lot of free resources on our website that you can find the, having to do with planetary defense. We have everything from frequently asked questions, things about Apophis, the asteroid in a close fly by in 2029, general frequently asked questions. There's an online asteroid defense class that I teach you in, just over an hours time, give you a basic introduction to asteroid defense and the types of things that our amazing panel work on. And we've also got infographics posters and then the budgetary analysis for the US program over time, from our political advocacy guru, Casey Dreier.

Mat Kaplan: And other great videos, those of you who joined us before the started the hour, you might've been treated to that series of dinosaur videos, that Bruce produced with our staff, Merc Boyan, our great video producer, absolutely entertaining. And those were all available on the website as well. I'll just add that The Planetary Society is proud to be a primary sponsor of the Planetary Defense Conference, something that we are really quite proud of.

Bruce Betts: I was just going to say this is an amazing conference, brings together experts from around the world in all the aspects of asteroid threat every two years, and we're just proud to be a part of it.

Mat Kaplan: And how we made it, thank you panelists. You've done an admirable job of presenting what each of you could have, we could have used the entire hour to present. For Misty West, who asked us on Facebook, and this is a great question, does the launch of all the Starlink and other microsatellites, all those big constellations of satellites that are now being launched. They have an impact on the surveys for asteroids that Kelly, told us about. And I know Kelly, do you want to take that first, but any of you are welcome to jump in.

Kelly Fast: Sure. I can say a few words. The surveys already deal with satellites that pass through their fields of view and leave streaks in their images, so it's something that they've been dealing with already, it will get worse with the increase in satellites. And it is more of a problem toward pre dawn and sunset, those times of day when the sun really lights them up relative to the sky. So it's something that they're already used to dealing with and continuing to deal with, better looking at, okay, how to deal with that larger volumes. So it will affect them, but it's not shutting anything down yet. So no worries there.

Mat Kaplan: Of course, we do have other astronomers who have expressed a good deal of concern about what may happen when these thousands upon thousands of new satellites start circling, our planet, does anybody else want to jump in on this?

Paul Chodas: Oh, let me jump in, just by saying that we have an advantage over the astronomers who observed galaxies and that sort of thing. Asteroids move, so that we have the opportunity, if they go behind the satellite and the streak of a satellite clambers one image of the asteroid, we may get it another time. So I think it will kind of degrade the efficiency, perhaps, if there is tens of thousands of satellites, but I think that surveys will still be able to find asteroids.

Mat Kaplan: That's reassuring. [Hothpop robot crosstalk 00:43:22], Love that, who asked us on YouTube, "Did the impact by Hayabusa on Ryugu, were we able to tell if it may have changed its orbit in a measurable way, even if only a tiny bit?" Masaki, and that's probably one for you?

Masaki Fujimoto: Well, first of all, the size of the grader is like 20 meter diameter, and the depth is like 3 meter, so it's really a tiny impact experiment. And I don't think there's a way, well, the amount was really small if there's any, deflection effect. And I don't think we have any way of measuring the delta created by the impact. So no, short answer is no.

Mat Kaplan: I'm going to speak for Isaac Newton here, and Nancy, I'll ask you, why do we have more confidence, looking at the laws of motion, that DART will generate a possibly detectable change in that motion?

Nancy Chabot: So, one of the reasons that DART is using this double asteroid system is because we're not changing the asteroid necessarily, as much around the sun, as we are changing the small moon asteroid that goes around the main asteroid. And that's really, what's going to make it more measurable and using the things here on Earth, that we'll be able to bring this in and have a deflection that Earth based telescopes can very easily measure. And I should mention that, that's happening in late September, of 2022. And that time is chosen because the asteroid and the Earth are actually minimize their distance.

Nancy Chabot: And so the telescopes on the Earth are going to be able to get really high precision data to really dial down what this deflection is because of that time. And that's why [inaudible 00:44:56] system is the time to do this first test.

Paul Chodas: Let me add a little math, there. The, projectile velocity makes a big difference, and a DART will be screaming into that little moon, and transferring a lot of its momentum in the mass of the spacecraft as well. Whereas with Ryugu, it was a little bit less velocity and certainly a smaller projectile, so unless the deflection.

Mat Kaplan: [Dean Sherman 00:45:22], who on YouTube asked us if in the future we establish bases on the Moon and Mars, could we also use those to track NEOs? And I'll add to that, would there be substantial value in using those other vantage points?

Kelly Fast: Well, certainly it'd be great to take advantage of any vantage points, but again, groups that have been assembled to study how to best do this, have pointed to space telescopes as being the way to go. And it's something that you can actually do now, we've launched space telescopes, and so if we want to keep going on the survey, we need to go with the technology we have now. Launched the space telescope, the NEO surveyor that we need now to keep racking up the discoveries. However, as these other technologies come into being, like the ability to have telescopes on the moon, then absolutely those should be added just like we have telescopes distributed around the Earth.

Kelly Fast: So there's no reason why not, but there's technological challenges to overcome, and so it's something that would be further down the road than the capabilities that we have right now at NASA, with our ability to launch space telescopes.

Mat Kaplan: Anybody else see value in putting telescopes up on our nearest neighbor, or on the Red Planet?

Nancy Chabot: [crosstalk 00:46:40] of astronomers If we want more telescopes, I think. So, yeah. [inaudible 00:46:44] I mean, but Kelly's right, the space-based surveyor is really what we need for the asteroid issue, and we need that as soon as possible.

Mat Kaplan: Another endorsement. Kelly, let me stop there and ask you, what is the current status of that spacecraft, which is, as you know, all of us at The Planetary Society have been looking forward to, along with you for years?

Kelly Fast: Right. Currently the NEO surveyor is going through development, it's being developed toward later this summer. It's a key decision point B, which we'll take it further through developing the design of this space-based telescope. And so it's the sort of thing that is continuing, as funding allows at NASA, to keep that development going.

Mat Kaplan: So here is a question from S McNeil, on YouTube, who asked which asteroid is forecast to come closest in the next century, and how closest it forecasted it to come, and how large is it? I think the name of that asteroid has already come up, hasn't it, Paul?

Paul Chodas: Yes. I think you're referring to a Apophis, which will approach-

Mat Kaplan: In deep.

Paul Chodas: ... closer than the satellites, on Friday, the 13th of 2029. April, Friday, the 13th.

Mat Kaplan: Because of the work that you and others are able to do now, how do we know that you're not off by a degree, a minute, a second, and that it really is going to come between us and the geosynchronous satellites.

Paul Chodas: I have a recent story and that is what we were able to predict the occultation of Apophis, and we heard a little bit about this during the Planetary Defense Conference. We know the orbit of Apophis so accurately, that we can predict the shadow that the starlight would cast on the Earth, and deploy observers to watch the shadow and see when when Apophis occulted that star. And so our knowledge of the location of Apophis, is down to within hundreds of meters. And this is typical of an asteroid that is really well observed by optical astronomers, and by radar. So we know the orbit of Apophis really, really accurately, and we can predict the close approach in 2029 with superb accuracy.

Paul Chodas: Now, a better question is what, what might happen if it goes through a keyhole and it could possibly come back and hit later? The recent radar measurements of Apophis, have enabled us to even eliminate that possibility. So Asteroid Apophis is now completely removed from our risk of asteroids that could hit the Earth over the next hundred years, because we know it's orbit so accurately.

Mat Kaplan: That makes me think of another question, and it brings up the tragic, terrible loss of the great dish at Arecibo, Puerto Rico, which of course was also capable of doing radar examinations of asteroids and other objects in the solar system. For any of you, how big of a loss is that dish, and should we be looking to replace it?

Kelly Fast: Well, it is a huge loss to the program NASA was funding the, radar that was done at Arecibo, which is an NSF facility, and had its other astronomical and atmospheric missions there. It was the most sensitive radar system on the planet, we still have the Goldstone Solar System Radar, which is very capable and it has the steerability that Arecibo didn't have, but it doesn't have the sensitivity, and so it was able to help kick Apophis off the risk list, was just fantastic. But there are still limitations on the sensitivity, and so it is something that is lacking, and it's the sort of thing that hopefully in the future, may be in coordination with other agencies, to look at possibilities for what capabilities might be available in the future, across the government for that sort of capability,

Mat Kaplan: Gerhard, you may be the best person to ask about this, although Masaki, maybe you're aware of something. With a Apophis, that close pass still several years away, is there discussion of sending up a spacecraft to observe it more closely, even though it will be coming so close to Earth, to get really close within tens or hundreds of meters?

Gerhard Drolshagen: Yes. Obviously, that is a very good opportunity to visit an asteroid, which is known to be something like 300 meters or slightly larger. The orbit is very well known, as we heard, it will pass within a certain distance, and this is known, up to a few tens of meters, the separation from Earth. So it's a unique opportunity to learn about the composition, also to test the spacecraft, the capabilities and visit it. Because we have plenty of time for a planning, and several activities are planned to send a spacecraft, just a reconnaissance spacecraft to Apophis, when it makes its very close approach on Friday the 13th, in 2029.

Gerhard Drolshagen: It will also be visible from the ground, and I guess everything including radar, and I hope a new radar facility will be available, we will put in place. And also certainly, spacecraft are plan to be sent there to get as much information as possible, because it will come close and it should not be too difficult to reach it. Of course, we try to avoid impact with Earth, but this is for our group, if the object is big, if a serious damage is expected. But smaller objects, as we saw from one of the charts from Paul, hit Earth all the time. So very small ones are just meteors or fireballs, but also objects can get bigger, some meter size that can be observed in space by optical telescopes, or by radar.

Gerhard Drolshagen: And of course, one aim is to find some that do eventually hit Earth, and you do not even try to deflect them, that could be harmless. But you see them coming, you can predict where will the impact, you can estimate what is the composition, and study the effects. And so far, this has happened four times that astronomers, planetary defense experts manage to see an object coming, that hit Earth afterwards. They we're all just in the meter class, no damage was done. In a few cases, meteorites are recovered on the ground and it's a very good test case to see them coming and see what happens, are our prediction all right?

Mat Kaplan: Another great development. Masaki, would you and your colleagues at JAXA like to see a mission to Apophis in 2029, or thereabouts?

Masaki Fujimoto: Just wanna mention that Hayabusa2 is on the second mission, it's now in the extended mission phase, and it will make a close fly by of one of the near-Earth asteroids, and it will rendezvous with another near-Earth astroid in 2031. And both of them are potentially hazardous astroid, so Hayabusa2 mission now has a more lighter defense flavor than before. So it's not Apophis itself, but Hayabusa2 is still working to contribute to the planetary depends.

Mat Kaplan: I wonder if, may be, you could also say something about the MMX mission, which is in a sense, an asteroid encounter mission, even though it's going to the moons of Mars?

Masaki Fujimoto: True. The science theme is about Who Brought Water to Earth, which was born dry. Hayabusa2 is pursuing that, as our samples from Ryugu, we will try to answer that question, but one sample is not enough. So we will get more samples from Phobos, one of the Martian moons, and we'll address the same question, analyzing the samples from Phobos. But at the same time, we may find some Martian samples that's been sitting on the surface of Phobos for a long time, so bringing sample backward Phobos may enable us to bring some Martian samples at the same time. In that sense, this MMX mission is our first Martian Mars exploration program for JAXA. It's not just a small body mission anymore, so it has a Martian exploration flavor JAXA.

Mat Kaplan: Bruce, does Apophis seem to present a nice opportunity for public outreach about planetary defense?

Bruce Betts: Yes, it does, man. I'm glad you mentioned that. Yeah, we've got an asteroid that's coming by that's big, 300 meters ish, but not scheduled to hit, but actually will be visible by a portion of the planet, including Europe. And it'll just be a dot passing in the sky, but I think it will be a great opportunity to raise awareness of the asteroid threat awareness of the work that people like those on our panel, and at the conference are doing. And to hopefully move us towards greater safety in the future from asteroid impact.

Mat Kaplan: I don't really expect any of you to have an answer for it, it's from [Mel Powell 00:55:50] who I happen to know as a wise guy, who listens to Planetary Radio, he asked us on Facebook, can we purchase Planetary Society Apophis protection helmets in case Paul Chodas, is off by a degree or so? Yes, Mel. We'll get right on that and add that to our store very soon, won't we Bruce?

Bruce Betts: Oh, yes. Yes we will.

Mat Kaplan: Paul, here's one, maybe you could explain the term you use. [Nikki Hyman 00:56:18] on Facebook asked, "What is a keyhole?" What is that keyhole you referred to in this context?

Paul Chodas: Great question, it's of a gateway near the Earth, so that if the asteroid comes in and misses the Earth, if it goes through this little gateway and sometimes it's less than a kilometer in size, sometimes it's tens of meters in size. But we can calculate that the asteroid goes through the little gateway, It's gravity will bend the asteroids orbit, of course, and then it will go into a different orbit around the sun, but by our calculations it could possibly hit. So when we take a look at the math and we run that backwards, we can figure out the size of the gateway that would lead to a possible impact years later, so that we call a keyboard.

Mat Kaplan: Here's our last question, folks. It comes from [Jay Harkey 00:57:13] on YouTube. Are there any resources available to educate amateur astronomers about how to collect the necessary information on NEOs, maybe become part of that tracking that Bruce talked about, that we fund through the Shoemaker NEO grant program, maybe also an idea of the equipment that might be required to become a serious observer of asteroids and NEOs? I think probably any of you could begin to address this, but Bruce, let's start with you?

Bruce Betts: I'm not sure there's a one-stop shop, I will point out the groups that do this. Some are individuals, some are groups of amateur astronomers, some are professionals. They have been doing this for a while and have pretty done advanced set up such as pulling out your six inch telescope in the backyard. So my suggestion would be to check out some of the observatories, you can find the Shoemaker NEO grant winners and look around for what they've got online, and at least get an idea of what type of facilities they have from our website and reports on those at, one word.

Mat Kaplan: Anybody else who wants to jump in on this, please do. And maybe also to say something about the importance of the contribution of amateurs, Kelly, did I see your hand?

Kelly Fast: Yes, I was just going to comment. Well, first of all, since you mentioned the important contribution of amateurs, there are some who have some, it's hard to even call them amateur facilities, because they're very substantial, with very good capabilities and actually contribute follow-up observations of asteroids to the Minor Planet Center. Some of them are members of the International Asteroid Warning Network, so it's fantastic. And I was also going to mention kind of at the other end of the spectrum, if you don't want to go out and buy equipment and you just want to put your toe in the water, there are a lot of citizen science opportunities, both in asteroids and in other areas.

Kelly Fast: And NASA has pages on citizen science, there're citizen science funded by NASA. The program that I manage funds the International Astronomical Search Collaboration, which allows school groups do a citizen science with images that come from the surveys funded by NASA, trying to find maybe things that were missed in the processing. And so, there are ways to get involved or just reaching out to your local astronomy club, or museums, once they open up. Just to at least, again, dip your toe in the water and find out a little more. And then of course, you mentioned Bruce's websites, there on The Planetary Society website.That and other areas are fantastic for education on how to learn about this, just to see how far you want to go.

Paul Chodas: There are some good resources that you can get, Eyes on The Solar System comes to mind, at JPL, and this JPL website, you can put yourself near an asteroid, on the orbit of an asteroid, all virtually of course. That's a good way to learn about the dynamics of the asteroids. And our website, I have to to plug it one more time, as I often do, the CMEOS group provides the complete list of all the close approaches. You can investigate what the next close approaches are, and it's a great source for all the stats on NEOs.

Mat Kaplan: Thank you panelists, and much more importantly, for everything that you are doing and will be doing in the future to help prepare humanity to defend this beautiful planet that we all share. We also want to thank all of you out there, who joined us for this public event today. We will, I hope, see you in two years at the Eighth Planetary Defense Conference. Thanks again, and have a great day.

Mat Kaplan: Want to see our great panelists, their slides and videos, drop by for the complete event. But not just yet, because Bruce and What's Up? Are moments away. Time again for What's Up? On Planetary Radio, fresh from the Planetary Defense Conference, where they save the Earth, I believe. The Chief Scientist of The Planetary Society, Bruce Betts, congratulations.

Bruce Betts: Well, it was an exercise. Things could have worked out better, but the real Earth is fine and has good views, the night sky. I got a lot to say, so I'm just going to skip to that if you don't mind?

Mat Kaplan: But I'm so curious, because Paul Chodas didn't tell us the end of the exercise, was Central Europe wiped out?

Bruce Betts: I can neither confirm nor deny the wiping out of Central Europe. It was an exercise. It was a very, very challenging exercise, as Paul probably discussed with you. He was truly devious, but it got people thinking about those really complex things, where you don't have enough time. The real bottom line is, you need the observations when you have the time, so you don't have the time, you just are so limited in what you can do other than evacuate, target evacuate all of Central Europe.

Mat Kaplan: See, I'm glad you didn't go straight to the sky. But now we're ready to go up there.

Bruce Betts: Okay. We got planets, we got all the visible naked eye planets are visible, although Venus is really tough. It's super bright, but it's very low in the west, shortly after sunset. Mercury is above it, not as bright, but a little higher up for the next few weeks. And they are coming closer together, Venus will get higher and easier to see, Mercury will get lower. They will be a half degree apart on May 28th, That's about the width of the full Moon. Speaking of the Moon, it will be hanging out near Venus on the 12th, though again, very tough to see, and that's right after this comes out. The 13th, hanging out with Mercury, 15th with Mars, Mars is up in the south west, looking radish in Gemini.

Bruce Betts: And then in the pre-dawn, we've got Jupiter and Saturn, very easy to see now in the east, south east, and the Moon will hang out with Saturn on the 31st, Jupiter on the first, but wait, don't order yet. The best is yet to come. I've got a total lunar eclipse I've arranged for you, and Ooh, actually I won't claim arranging it because half the world will be mad at me for skipping them. A total lunar eclipse May 26, thanks to a International Date Line, it's May 26th, wherever you are, centered basically on the Pacific Ocean. So if you're in Eastern Asia, Australia, New Zealand, you'll be able to see it starting in the evening of the 26th.

Bruce Betts: And if you're in the Eastern Pacific, as we are Mat, you'll be able to see it in the pre-dawn skies. And if you're very far off that center, you won't be able to see it. It's a short totality this time, It's about 15 minutes only of totality. The Moon is just passing through off center in the shadow of the Earth, and so it's a short totality. You can find out more at the NASA eclipse page, or at, does a nice job customizing it for your location, what you'll be able to see.

Mat Kaplan: Man, that is busy. So will Southern California be in the path of totality?

Bruce Betts: Yes. Except for the most southernly part of it, because of you. Now, yes California, the West Coast we'll see it totality, by the time you're in the middle of North America, middle of the US. You'll be seeing it just in totality at sunrise, and if you're on the East Coast, you won't be seeing the eclipse much at all. And if you're in Europe, well, there'll be more, there'll be others.

Mat Kaplan: Just be glad you survived the exercise, if you're in Europe.

Bruce Betts: Just be glad this is only a test. Should this have been a real asteroid impact? Well, let's make sure there's not one. Okay? We move on to [inaudible 01:05:19] fact.

Mat Kaplan: Men, I thought it would never end.

Bruce Betts: I thought I'd go on farther, but I just figured everyone would already hate. So, I like this one, the Perseverance Mars Rover, you've probably heard of this. It is about the same mass as the car, the Chevy Spark. It only weighs currently 38% of a Chevy Sparks since all Chevy Sparks are on Earth, and the one Perseverance is in Mars, gravity. But their mass is about the same.

Mat Kaplan: I was going to say something about the Chevy Spark, but I didn't want to get in trouble with General Motors, so I won't. That's interesting, I've heard it compared to a golf cart. I guess you could compare the Spark to a golf cart, as well.

Bruce Betts: Yeah. It's hard to find a car that's that low i mass, but it's massive dude.

Mat Kaplan: And the Spark is not, good on your Chevy.

Bruce Betts: So much for that sponsorship. We move on rapidly to the trivia contest, and after that comment, I think you won't be as surprised when we find out who the asteroid Kaplan was not named for, but we will find out who the asteroid Kaplan was named after. How'd we do Mat?

Mat Kaplan: Kind of a really nice response, a whole bunch of very sympathetic listeners. Thank you, everyone. We'll hear from a few of them, but first tell us who is it named after?

Bruce Betts: It is named after cousin Samuil.

Mat Kaplan: Uncle Sam?

Bruce Betts: Your uncle, Sam, who ironically, perhaps, is a Russian, Soviet astronomer, Samuil Aaronovitch Kaplan, lived from 1921, 1978. He was a Russian astronomer and astrophysicists at Lviv University Observatory in the Ukraine and at the Radio Physical Research Institute in Nizhny Novgorod, in Russia. He did a bunch of astronomy stuff with white dwarfs and solar radiation, [inaudible 01:07:22] that kind of stuff.

Mat Kaplan: Are we related? A lot of you wondered, I don't know. I've never had a genealogy study or DNA or anything like that, he probably didn't either. Maybe a descendant?

Bruce Betts: Yeah. I'm guessing he didn't have a DNA test that, Okay, go ahead.

Mat Kaplan: Robert Johannison in Norway, discovered the same thing you did, that this Kaplan... that Kaplan, I should say, worked at the Radiophysical Research Institute, where they do research in the fields of Radio, Radio Astronomy, Radio Engineering, you can see where I'm going here? So radio.

Bruce Betts: It unites all the Kaplans of the world.

Mat Kaplan: Yeah. I tell you, that's the apple doesn't fall far from the Institute, I guess. Here's our winner, she's a first timer, Jennifer Dobbins, in the state of Florida, which is a state of mine. Jennifer, congratulations. You got it with Samuil Aaronovitch Kaplan. And I believe that Jennifer has one last copy of the new pocket, Atlas of Mars. Which is that terrific little book, little pocket book. It'd have to be a big pocket, but it's still kind of pocket size, assembled by Henrik Hargitai. Jennifer. I bet you'll be able to get a little cutout, a little overlay of the state of Florida, that you can use on these beautiful maps.

Mat Kaplan: I'm looking at mine of California right now, that I can see right through. Also from Europlanet, thier Central European Hub. And that's the last one of those that we're going to give away. You may be able to guess what we're going to give away in the new contest, but here's some other stuff first, [Mark Dunning 01:09:04] in Florida, "Imagine my shock and disappointment when I learned it, wasn't named after our Kaplan, I mean, sure. Samuil was probably a great guy and all, but Come on, Minor Planet Center, there's room for two Kaplans in our sky, and maybe even more."

Mat Kaplan: From [Elijah Marshall 01:09:21] in Australia, "You guys need to get in contact with the Catalina Sky Survey, and get Mat and Bruce's names on asteroids. After all Bill already has 19695 Billnye." I didn't know the boss had an asteroid, not surprising, I guess.

Bruce Betts: Well, ours will be better. No, I'm kidding.

Mat Kaplan: We're kind of coming to that. [Cameron Landerson 01:09:46] in Texas, "Best of luck to Bruce, at the Planetary Defense Conference," he sent this before the conference, of course, "they'll need it once they have to deal with the soon to be discovered 2021, Mat Danger Kaplan. Perhaps he'll think twice about using his middle name." [Eason Beglu 01:10:05] in Ontario, Canada. "Now I'm wondering what Bruce's full name is, is the asteroid 21506 Betsill named after him?"

Bruce Betts: Sure. The Betsills changed our name from... No, it's not. It's definitely not.

Mat Kaplan: [Michael Kasbowle 01:10:26] in Germany, "Maybe the Rubble asteroids could go by the name, Mat Kaplan?"

Bruce Betts: Oh, I love that.

Mat Kaplan: All of them or just one? From our poet Laureate. [Dave Fairchild 01:10:40] in Kansas, "Kaplan is an asteroid, we'll visit it someday and make it part of what will then be called the OPA," Expanse reference, for those of you who aren't immediately aware of it, "it honors astrophysicist, and Samuil's his name, so when will Mat our friendly host receive his claim to fame?" Finally, this a major bit of hope from Edwin King, in the UK. "Hang in there, Mat. You might get an exoplanet."

Bruce Betts: Ooh, I stopped there. Let's violate all the rules and give you, maybe a dwarf planet in the solar system.

Mat Kaplan: That'd be appropriate, wouldn't it? Yeah.

Bruce Betts: We could rename Uranus. I mean, everyone's always been uncomfortable with that in the English speaking world. So it was supposed to be named after King George, so it's named after King Mat.

Mat Kaplan: If it's my planet, I guess I would be royalty there. So I think that's appropriate

Bruce Betts: And we'd be happy to send you there if we possibly can.

Mat Kaplan: Yes, yes. I should have known. We're ready.

Bruce Betts: You're so ready. Coming back to near-Earth asteroids, Here's your task. Name all the near-Earth asteroids that spacecraft have touched? Oh, all the near-Earth asteroids that spacecraft have touched, go to

Mat Kaplan: Ooh, be careful with this one, everybody. You have until the 19th, that'd be Wednesday. May 19, at 8:00 AM. Pacific Time, to get us this answer. And have you guessed it? I got your near-Earth asteroid right here, it's made out of rubber, and it could be yours if picks you and you've got the right answer for this one, keep those cards and letters coming and go [crosstalk 01:12:27]-

Bruce Betts: Rubble asteroid MatKaplan, the prize on this week's Planetary Radio.

Mat Kaplan: Mat Danger Kaplan, I like that. I think I'm going to change my middle name. Say, goodnight, Bruce.

Bruce Betts: Goodnight Bruce? All right, everybody go out there and look up in the night sky and think about what around your house you would like to name Mat Kaplan.

Mat Kaplan: We used to have a dog house, which... wouldn't have been appropriate.

Bruce Betts: Then it would just be confusing, because Mat would always be in the math.

Mat Kaplan: He's Bruce Betts, he's the Chief Scientist of The Planetary Society. And he's always right here with us inside What's Up? Planetary Radio is produced by The Planetary Society in Pasadena, California, and it's made possible by its members who are just trying to save the world. You can become a planetary defender at Mark Hilverda is our associate producer, Josh Doyle composed our theme, which is arranged and performed by Pieter Schlosser. Ad astra.