Planetary Radio: Space Exploration, Astronomy and Science - Hayabusa2 Reaches a Dark Diamond in Space

Episode Date: July 25, 2018

Japan’s Hayabusa2 is just 6 kilometers from asteroid Ryugu as it prepares to snatch samples of the space rock for return to Earth.  ISAS/JAXA Director General and former Hayabusa Mission Project Manager Hitoshi Kuninaka joins us for a conversation about the spacecraft and what’s ahead.  Then we hear from Hansjörg Dittus of the German Aerospace Center (DLR) about the German/French lander called MASCOT that was carried to Ryugu by Hayabusa2. Emily Lakdawalla is the new editor of the Planetary Society’s distinguished magazine, The Planetary Report.  Bruce Betts explains how to get the most out of a lunar eclipse and the closest Mars has come to Earth for many years.  We also give you an extra week to enter the space trivia contest! Learn more at:   http://www.planetary.org/multimedia/planetary-radio/show/2018/0725-2018-kuninaka-dittus-hayabusa2.htmlLearn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Visiting a dark diamond in the sky, this week on Planetary Radio. Welcome, I'm Matt Kaplan of the Planetary Society, with more of a human adventure across our solar system and beyond. After traveling across much of our inner solar system, Hayabusa 2 is now a hair's breadth from asteroid Ryugu. It won't be long before the spacecraft touches down on this diamond-shaped mystery. Before it does, it will release a tiny lander called Mascot. We'll talk with Hitoshi Kuninaka, leader of the Hayabusa 2 mission, and then with Hans-Jörg Dietes, executive Board Member for Space Research and Technology at the German Aerospace Center. Mars is almost close enough to touch. Okay, not quite, but Bruce Betts is ready to share the great view with us. We begin with Senior Editor Emily Lakdawalla, who has just

accepted a big new job at the Planetary Society. Welcome back, Emily. Tell us about this big new task that you've taken on. You're speaking to the new editor of the Planetary Report. Now, some of the people listening to this show may not be familiar with the Planetary Report, but it's actually a 40-year-old magazine that circulates to about 50,000 people. It's the member magazine for the Planetary Society. It was started in 1980 by Carl Sagan. It was developed by Charlene Anderson, who would later mentor a young planetary science graduate into a science writer. I'm talking about me, of course. And then it was nurtured into its present state by Jennifer Vaughn,

who's now our chief operating officer, and Donna Stevens, who retired last month. It's an honor to be put at the helm of this magazine with such a legacy. It contains a lot of writing by luminaries like Carl Sagan, but also lots of engineers and scientists and astronauts and futurists and space artists. I'm looking forward to carrying its tradition on into the future and maybe bringing it into a little closer alignment with what we do on the web and having the website be influenced by the magazine as well. Yeah. I mean, how do you build on this kind of success? Can you be more specific about what you hope to do with the magazine?

Well, the magazine has always featured the voices of the people actually performing the exploration of our solar system and the universe beyond. And I don't plan to change that. I think it's one of the wonderful things that the Planetary Society does, connecting the active space explorers with the armchair space explorers, the people who enjoy the fruits of planetary exploration so much. So we will continue to do that. The pages will continue to inform people about what the Planetary Society is doing. And I will continue to feature amazing photos. I'll probably start featuring more of the particular kinds of photos I like, which are ones that are dug out of planetary image archives by amateur image processors. So I hope to feature more of those people in the pages.

to feature more of those people in the pages. I also have been looking at the catalog of what the Planetary Report, the subject matter that it's featured in the last several years. And I found a few subjects that have gone maybe a little neglected. So I'm going to be featuring some articles on some neglected planets and places in the near future.

Well, as a member of the society, as well as an employee, I always look forward to a new edition of the Planetary Report. And I can't wait to see what this new era will bring us, Emily. Thank you for taking it on. When will we see that new issue, we members?

So my first issue will be the September equinox issue, and I can tell you now that it's going to feature articles on new missions to explore Mercury and the Moon. Very much something to look forward to. And you can learn more, of course, at planetary.org. Thanks, Emily. We'll continue to talk to you about other things around the solar system as well, I hope. Yes, indeed.

That's Planetary Society Senior Editor Emily Lakdawalla, and that title now includes her leadership of the Planetary Report. We're moments away from talking with Hitoshi Kuninaka, leader of the Hayabusa 2 mission. Remember Hayabusa? I started calling it the little spacecraft that could. The Japanese mission to asteroid Itokawa faced and overcame challenge after challenge, finally returning a tiny sample of that space rock to Earth.

JAXA, the Japanese space agency and its Institute of Space and Astronautical Science, learned a lot from that experience. Now, Hayabusa 2 is almost ready to descend to asteroid Ryugu. Hitoshi Kuninaka leads the mission. Professor Kuninaka is also an expert in electric propulsion and plasma engineering and has been deeply involved in development of the ion engines that have driven both Hayabusa explorers across the solar system. He was in Pasadena, California a few days ago for COSPAR, the International Committee on Space Research 2018 Scientific Assembly. He found time and a very busy schedule to spend a few minutes with me for Planetary Radio.

It's my pleasure to talk in this program. It is our great pleasure and honor to have you as a guest on Planetary Radio. So again, thank you very much for taking a few moments out of your time here in Southern California to join us. Hayabusa 2 is now 20 kilometers, maybe 12 and a half miles from your target, asteroid Ryugu. It seems to be going marvelously, absolutely perfectly. You must be very proud of your mission. Yeah, thank you very much. But from now on, we will start the proximity operation.

That is the space exploration. And so we are very nervous to go the safety, we can do the safety operation or not. But all of the staff, Hayabusa 2 team, are very keen to access such a phase. I'm very proud of them. You have a great right to be, and your mission has attracted worldwide attention. It has been in all of the newspapers here in California, I know,

and around the world. You probably have seen Dr. Brian May's stereoscopic images. Yeah, we are very happy. So that a lot of people interested in our space missions, and Brian May make a 3D stereo image. We are very proud of it. And some of my colleagues at the Planetary Society have also been writing about the mission since before your launch. In fact, even just recently, Jason Davis, he had a piece on July 5th about sample return, which I hope we can talk about in a moment or two, since that is the great goal of this mission. But as recently as July 11th, he included in a blog post at planetary.org some of these utterly, I will say it again, spectacular images

that are already being returned. What's ahead of us here? You'll be moving in closer soon, right? Yes, so the present state, we stay the present position, 20 kilometers apart from the target asteroid. And then so we take a lot of data using the onboard camera and IR instrument. July and August, we get a lot of information about asteroid Ryugu. And then summarizing the order of data, we will determine the landing location. We select the site to deliver, dispatch our separation robotics. And then so that the whole of the identification and determination in the next phase, we will move on to the next phase that is the proximity operation. And before we go on, you mentioned an IR instrument, and that's an infrared spectrometer,

I think, that you're carrying as one of the instruments on the spacecraft. Yes. You're closing into what the next step is, I think, five kilometers from the asteroid? Closing into what the next step is, I think, five kilometers from the asteroid? Yes, before the real touchdown operation, we tried to descent operation, so to approach to the vicinity of the asteroid to get the more detailed image. When will the spacecraft begin operating autonomously? Because I know that as you get closer to the asteroid, like many missions now, that 40-minute light travel time between us and Ryugu, 300 million kilometers away,

you really have to rely on your spacecraft's intelligence. So the previous mission, Hayabusa-1 mission, we have a lot of failure in the space operation. mission, we have a lot of failure in the space operation. In the case of the Hayabusa-1, we missed the release of the projectile at the moment of the touchdown. In that result, so collecting sample is a very tiny one, so several milligram or a microgram. But it worked. You made it back with that very small sample. Yeah. So that's a kind of the malfunction. We do not make a computer system so precisely. Based on that lessons learned in the Hayabusa 2 case, we executed a lot of the simulation in the computer simulation and the machine interface simulation.

And in that sense, we executed a lot of the preparation for the exact touchdown operation. I can tell you that all of us at the Planetary Society, as we followed Hayabusa 1, we really felt it was a heroic mission because it did face so many problems. And yet, you made it back with a sample. What has changed? You had all of that data from that first mission. I know you made a number of improvements to Hayabusa 2. Yes, I am an engineer of the electric propulsion in the ion engine system.

So I took charge of the development and operation of the ion engine dedicated for Hayabusa 1 and 2. During the operation of Hayabusa 1, we experienced a lot of the malfunction in space. So especially for the ion engine, we had a lot of the interruption of the operation using the ion engine. Our system was not sophisticated. Parallel to the Hayabusa1 operation, we started the next R&D for our ion engine. In those days, Hayabusa2 was not decided. We are focusing on the future application, not Hayabusa 2. In case of the Hayabusa 1 ion engine, thrust force is 8 millinewton. Thrust force is 8 millinewton. The next challenge, we made 10 millinewton.

So 25% increase in your thrust. That's right. That's right. Improved one. And then so in that sense we prepare for our ion engine technology focusing the future mission. And then after the Hayabusa 1 termination, Japanese government decided to go to the next asteroid sampling term mission that is Hayabusa 2. And then from the year 2011, we apply the new improved ion engine system to Hayabusa 2. Based on the lessons learned of the Hayabusa 1 inbound journey from us to target asteroid from 2014 to 2018, this year, so these 3.5 years, so that the perfect operation for the ion engine, so that no interruption of the operation in space.

And I read that these ion engines are driven by microwave, which is quite innovative. We know and are very excited about what ion engines enable spacecraft to do. I'm sure you're familiar with the Dawn mission, which is the orbiting series, of course. Could you have achieved what Hayabusa 2 and Hayabusa 1 have done or are doing without ion engines if you had had chemical propulsion? Yeah, that's right. The Japanese rocket system is a very tiny one, so we do not have the capability to send a large amount of the mass to deep space. We need high-efficient propulsion system that is electric propulsion ion engines. We need high-efficient propulsion system that is electric propulsion ion engines.

As for the Japanese case, usage of the ion engine is a unique solution to make round-trip space missions. It is an exciting innovation. You have a number of other innovations that are part of this spacecraft, including how it will be returning data and receiving commands, how it is receiving commands from Earth. I know that part of your collaboration with NASA, you're making use of the Deep Space Network. Yeah, that's right. Japan has the only communication dish in the vicinity of Japan. Communication time is very limited for the deep space operation.

On the other hand, NASA has a lot of the dishes in the worldwide, So Goldstone, Madrid, and Canberra, that is a deep space network, very effective and powerful communication system. Hayabusa and the Hayabusa 2 case was supported by NASA or DSM. You mentioned that the Japanese government had said they wanted you to use this new and improved ion engine technology. You only had two and a half years, I believe, from the time you were told begin to build Hayabusa 2 to when you had to launch this spacecraft. That's an extraordinarily

short amount of time to create a spacecraft, isn't it? In Hayabusa 2 case, for the developing time frame is only 3.5 years. That's a very tiny one. That is one of the problem, one of the issue to be solved in those days. So company staff and JAXA's people are working so hard so that we accomplish our system in time for launch. And I was off by a year, but that's still an extraordinarily short period to be able to pull a spacecraft together. I'd like to hear more about some of what you are also carrying on the spacecraft,

in particular these little rovers that are called Minerva 2. Minerva 2 and the mascot. Yes. Tell us about Minerva 2, first of all. Original Minerva 1, dedicated for Hayabusa 1 mission. We released the Minerva robotics from the spacecraft, but unfortunately we failed to land on the surface of the asteroid Itokawa. At the moment of the release, we take only one picture from the mothership Hayabusa, but the Minerva cannot reach to the surface of the asteroid. In the Hayabiscus II, so we have a next trial.

So we install the three Minerva II. Next time opportunity, we want to succeed the landing operation of the Minerva II. And these are actually, they've been called rovers, but they're actually more hoppers, right? Yeah, that's right. Very low gravitational field environment so that they can move by hopping manas.

How will you take material from the surface where you go, actually from under the surface? You have an impactor. Can you talk about how that will work? One of the lessons learned of the Hayabusa-1 mission, the collected surface material is affected by space weathering effect. Under the ground, we may have very fresh material. The Hayabusa 2 mission, we installed the impactor. We call this small carry-on impactor. It installed the chemical powders. The ones we explode chemical reaction,

we accelerate the copper pallet. It's almost like an explosion firing a bullet or a shell into the surface. You make a little crater. Yeah, that's right. And is it at that moment that the sample material is blown up into the collector? No. So that is a relatively dangerous operation. You don't want to be too close. Yes. So once the impactor was separated from the mothership Hayabusa 2, it will take an escape maneuver to go to the another side of the asteroid. And then several tens of minutes later, impactor automatically

explode. At that moment, maybe a lot of the fragment will be scattered around environment. Some of the fragment may have a very high velocity. So once we have a collision, so we have a very serious phenomena. So that in order to avoid such kind of phenomena, so a spacecraft takes the escape maneuver. Tenth day later, fragment will be disappeared. And then so spacecraft come back to the original position. And then so it will search the nuclear crater, and we will take another touchdown operation vicinity of the nuclear crater. Something that struck me when I read that the impactor is made of pure copper, I remembered,

I think, that on the deep impact mission, which impacted a comet, that impactor was also a copper sphere or copper bomb. Ah, yes, that's right. Why copper? That is a very difficult question. We use the specific technology, exploded deformation impactor technique. That is commonly used copper material

because copper is easy to expand. Ah, okay. That is a unique metal to apply such kind of technology. So all of this is still ahead of us, and the greatest feat that is still ahead of us is 10 days after this impact, collection of the sample, and then soon after, you begin the return trip to Earth? Yes.

Proximity operation of Hayabusa will take 1.5 years. During that proximity operation, we have a two-month conjunction time frame. So in that time frame, we cannot communicate with spacecraft. So two months rest. First of all, this year, 2018, we want to try to execute two touchdown operations. And then next year, we will try the impact operation. And then after that, we will try the third trial of the touchdown. And then end of 2019, spacecraft leave for us.

And then the return capsule, reentry capsule, comes down in Australia, is collected. What happens with that sample material after that? Does it go to a lab in Japan? We will take the same manner of the Haibusa-1 mission. And first of all, we will search the landing position of the capsule. We fly to there by helicopter, heliport mission. And then so we will pick up the returned capsule. So after that, we will hire the business jet. And then from Umera, we will take the directory flight from Australia to Haneda. And there to enter into, I'm sure, a very clean lab. Yes, that's right.

To begin to examine this material. What are the scientists hoping to discover? Because I know that because of the type of asteroid this is, a type C asteroid. That's right. They are hoping that it will have some very, very interesting materials. Yeah, yeah. This asteroid Ryugu is classified to C-type asteroid. C means carbonaceous chondrite type asteroid. So the scientists thinking about it contains water or organic material. These are expected. We are now making the new

curation facility in Sagamihara, Japan, to adapt the Ryugu materials. Scientists want to take a signal of the water or an organic material from the collected sample. Yeah, it's pretty exciting because we really are looking back into the past of our solar system, right? And to conditions that may have led to life on Earth. Very exciting. That's right. Asteroid is the fossil of the solar system. A fossil, yes.

Yeah, that's a good way to put it. The Earth's material is a lot of the weathering and the temperature effect, so that the whole of the material is changed. So asteroid and the comet in the solar system keep in the ancient situation of the solar system. There's one other instrument that I want to ask you about before we talk about your partner in this, the DLR.

And that is something that's on the spacecraft that was funded by donations. And I saw a show of gratitude. There was a thank you message from you to people who put this there. Can you tell us about this? So we gathered the donation to the Hayabusa 2 mission. And then so we gathered the people's name in the digital manner. We installed the small memory. And then we make film fish.

And then so we install the name list. And we love sending people's names across the solar system at the Planetary Society. Was there a camera as well that was supported by, I saw, Cam-C? Cam-C, yeah. That was supported by donations? Yes, that's right, that's right. Based on donation, we developed the Cam-C. The Cam-C will take the touchdown operation. It will take

exact touchdown locations. As for the name list of the donated people, that film is installed in the target marker. So we installed the five target marker. Before the touchdown operation, we release the target marker on the surface of the asteroid. That actually goes to the surface and then helps Hayabusa to find the spot. That's right. The list is installed in the target marker, so this list will be landed on the surface of the asteroid. And with any luck, we'll sit there on the surface of that asteroid for another four billion years.

Maybe, maybe, if it doesn't hit anything else. This represents something that I know is important to you, and that is the power of a mission like this to inspire, to bring members of the public in, young people especially. And this is important to you. I think so. I have already said to you, so Hayabusa 2 has a lot of the barriers to develop the short time duration. It was accomplished by the very young people who are inspired by the story of Hayabusa 1 mission. So we finally succeeded to the Hayabusa 2 spacecraft in time for launch. One of the most delightful things that I think JAXA, ISS has done is, I know with Hayabusa, there was a little sort of a cartoon character that was developed,

represented the spacecraft, and became very popular, right, in Japanese society. I think so. So commercial movie maker make a lot of the several movies for commercialize.コマーシャル映画の作者は 多くの映画を作っています そのため 日本で 非常に有名な 映画の一つの物語が 早草です この秋に 別の発表会議を 行っています ペピ・コロンボの イーサーとジャクサーの 共同ミッションです マーキュリーに スペースクラフトを 送っていきます we will send our spacecraft to Mercury. Another space program, JAXA, ISAS, is now developing the lunar surface landing mission.

We call it SLIM. And then, so, future mission, MMX Martian Moon Exploration Program. So, sample return mission from the Phobos or Deimos. So, 2020s, we want to realize, deliver our space asset to the solar system from Mercury to Jupiter. So they are our space asset, so JAXA's Deep Space Frito. Based on that, such kind of the swarming technology, we want to investigate solar system. These are ambitious plans.

How important is international partnership or collaboration in achieving these? That's a very, very important factor. So JAXA is the daughter partner, minor partner. In the other case, we are the major integrator or a major player of the space mission. In the minor partner case, we deliver a small component or a separation robotics to another space agency. In the opposite case, we receive the component from the international agencies. And then so we bring such device to the target. That is a collaboration. In that case we have a mutual benefit to each country.

If we promote such kind of international collaboration, we can make a good relationship between two countries or many countries. Not only space topics but also whole kind of the issues. Yes. That is the final goal, I believe. Just one other question, a somewhat personal one. You've said that exploration is in the human heart. Does that help to drive your work on this mission and the other missions that are upcoming? From now on, JAXA, not only JAXA, but also all of the international,

will go to the next step of the space exploration program. It will stimulate us and then to encourage the company's activity and accelerate technology advancement. Space exploration will stimulate human beings, I believe. But for you personally, you find it stimulating? So, I get the... It's in your heart, you said. I get very senior person, but yeah, President State, I take the Director General of the

ISSAS of the JAXA. So, we want to encourage our staff of ISIS people and then expand this passion to the Japanese community and worldwide. Thank you again very much. It has truly been an honor to speak to you. All of us wish you the greatest of continued success with Hayabusa2. We look forward to the return of those samples and the great science ahead. Thank you very much. Finally, I want to say May the force be with us. Yes.

One would hope. Hayabusa2 project manager Hitoshi Kuninaka on Planetary Radio. Hans-Jorg Dietes was also in Pasadena for the biannual COSPAR Scientific Assembly. This expert in gravitational and other fundamental physics served as director of the German Aerospace Center, or DLR's Institute of Space Systems. He was appointed as DLR executive board member for

space research and technology seven years ago. The DLR has worked with partners in France to develop Mascot, the mobile asteroid surface scout, a tiny lander that has been carried to asteroid Ryugu by Hayabusa 2. We'll hear more from Professor Didis about the DLR next week when we'll continue our coverage of COSPAR. Our conversation this week focuses on that little lander that will soon begin its explorations. Professor, welcome. It is an honor, as I told Professor Kuninaka, who was sitting in your chair maybe 10 minutes ago, an honor to speak to him, an honor to speak to you, not just about Hayabusa II, although I hope we can start with that, but about what the agency that you help to run, the DLR, the German Aerospace Center,

what it accomplishes and how it accomplishes it. But first of all, as I said, welcome. Thank you. It's a pleasure for me as well. Well, Professor Kununaka, you will be happy to hear, had very nice things to say about their partnership and collaboration that they have with you at the DLR. But I know it's not just the DLR. There is at least one other agency that is very involved with what has come to be this spacecraft that is part of the Hayabusa 2 package. Very much as Cassini carried Huygens to Titan, Mascot is being carried to Ryugu.

Yeah, that's right. This is a trilateral partnership for these Hayabusa 2 spacecraft. And in particular, the lander, where we talk about it's called the name is Mascot. We do it together with our French partners. And so to say is a Japanese-European project. and so to say is a Japanese European project. Nevertheless, we have as DLR a long-term partnership with JAXA as a strategic partnership where we try to do a lot of other projects as well. It's not only exploration.

But this specific project, Mascot, where we built the lander for Hayabusa 2, is done together with our partners in the Centre National d'Etudes Spatiales in France. CNES? Did I get it correct? Okay. We call them CNES, yeah. Okay. MASCOD, the Mobile Asteroid Surface Scout. Tell us about this little spacecraft? Yeah, the idea came up after Hayabusa 1, when the Japanese asked us maybe to bring up another spacecraft. At that time, it was a national project,

as you may remember, with high attraction at that time. It was in 2011 when there was a decision made by the Japanese Space Agency. And as you might remember, that was the time when they had this terrible earthquake, the Fukushima earthquake. It was becoming a national symbol, was Hayabusa 1, and the Hayabusa 2 became a very important mission. And at that time, we had a discussion in Europe and in Japan how we can make it together. But the problem was it should be a very small lander only. 10 kilograms was the maximum mass.

Tiny. This is really tiny. Very low mass. So to say two shoeboxes. At that time we called it the shoebox experiment and not more. And the question was what to do? Is it possible? So we did studies

together with French partners and we said okay, we can do it. It was clear that the lander is not massive. It had no active landing mechanism. It's just passive. We throw it out of the spacecraft. It must land, approach slowly, really carefully.

Otherwise we could be rebounced and this was a risk. At escape velocity? Yeah, yeah, yeah. Escape velocity on Ryugu is not much. It's not much. It's some centimeters a second only. So you have to approach very carefully.

And if you have no landing mechanism, if you have no dampers on board, as we did it, for example, on landing on Churyumov-Gerasimenko, As we did it, for example, on landing on Churyumov-Gerasimenko, where we had active systems, dampers, anchors. Yes. And there are many, many ideas to fix it on the surface. It's not the case here. So we land mascot completely passively. It falls down. And the hope is, oh, not the hope, but we know it's slow enough not to become rebalanced.

And when it lands, you don't know what side it's going to come down on. It's roughly cube-shaped or rectangular, but you can, it will right itself. Yeah, there's a mechanism that we can turn it upside down or downside up. There's a clear downside for the

spectrometer on board. It's called the microarmiga. It's a French contribution. It's an instrument where we can get information about the surface on which we land. And then there's a mechanism where you can catapult it up. It's just an extender motor. It's a tiny thing because escape velocity is small. Gravity is small.

So it needs a tiny force to bring it up. And it shouldn't be too much, just to give them a push to hop on the surface. Is this just a mass that moves inside the spacecraft? It's a small mass on an extender motor, but it's really small. It's maybe a mass of some grams only, 100 grams. Like this is just enough and you move it fast and then it hops up. I have a wind-up toy at home that works exactly the same way. It has a little eccentric weight. You wind it up and then it just kind of bounces across.

Yeah, it's the same. But in that case, it bounces a much longer distance. So it goes up, falls down very slowly, and touches the ground a little bit distant. That's why we hope that we can do in a time where we're on the surface, where we can operate actively on the surface, roughly maybe three different sites. But these are defined by accident. It falls down. It cannot be… You can't say, like Curiosity rover, let's go over there and look at that rock. You have to get lucky.

No, no, no. You have to be lucky. And it's a fairly short lifespan because, like Huygens, we mentioned Cassini-Huygens, you have no solar panels. So once you run out of battery power, that's the end? That's the end, yeah, indeed. That's what's a compromise to make it small. We have only batteries, and if they are down, we are done.

So what is the science that you hope to accomplish? You mentioned this instrument provided by the French, which is a spectrometer? It's a spectrometer, It's a spectrometer. And we have a magnetometer on board. I think it's also important to know about the magnetic field or get some magnetic field information. This has been built at the Technical University in Braunschweig in Germany. And then there are two other instruments. There is

a radiometer, a camera. It's actually charming to think of this little box loaded with scientific instruments bouncing or hopping across the surface of this world that has been out there for billions of years and is now only being visited for the first time, as far as we know, by anything intelligent. How is the signal returned to Earth? Yeah, this is only possible via the orbiter. We have a weak communication line, so to say, to the orbiter. And from the orbiter, then it's transferred to Earth.

Again, like Huygens. Again, yeah, like Huygens. It's the same idea. You can do it only via the orbiter because otherwise you would need a very strong antenna system on board of the spacecraft. That's not the case.

This is another compromise. We made a lot of compromises to make it small. The science that may come from this, we talked a little bit about this with Professor Kuninaka, but you are a scientist and I know you have a lot of colleagues who are very excited to be visiting this Type C asteroid. The question is always if you land, what is most important to measure? And of course, if you land on an asteroid, the big question is,

is there any information with respect to what happens in the early time of our solar system? Because we think that these are the relics of the early times of our solar system, these asteroids. So the question is, is there some information about how life could come up in our solar system? Are there organic molecules? We can find them.

So we have to look for that. Is there some information about water? Is there water? The question is still one of the big questions we have in our solar system, how the water came to Earth, how so much water came to Earth, and why is it only on Earth and nowhere else. These are the questions. And if you bring up instruments on a body like that,

it's always a question of priority, what is most important to measure. I think the most important thing is if you land somewhere, you have to measure where you have been landed. And this might be one of the key questions also for Huygens. Huygens landed, but there was no information where we really landed. We only have, so to say, information on other channels, but we couldn't measure that directly. Not directly anyway, yeah. And you see, this is not a desert one. It was one of the major missions in space we did in the last 50, 60 years.

It was landing on Huygens, on Titan by Huygens. But at the end, we have no information where we landed on. There are many, many other information, quite interesting information. where we landed on. There are many, many other information, quite interesting information. So I think the most important information if you land on an asteroid is where we have landed, how it looks, the material.

Ryugo, the Japanese selected this Ryugo as a C-type asteroid. So C-type means it's a contrite sun, a more organic material than what we expected. The last one was not a C-type. It was an S-type asteroid. That was the Itokawa. Itokawa.

So there is definitely a different material. That's what we know now. So now we expect different materials. So material is important. All the other information, of course, as well. But I think the most important thing is the material of this asteroid. Another thing is, and that's what we learned from the first pictures, it's a very dark asteroid, very, very dark, only 1.5% of albedo. That means it's a piece of coal,

so to say, where we land. Not from the material, as it looks like. Just incredibly dark. It hardly reflects any light at all. A piece of coal in the night. Yeah, yeah. But that means that it's absorbing a lot of energy. It's hot there. We expect surface temperatures of roughly 90 degrees Celsius.

Really? I had no idea that it would be that high. Yeah, it's high. My goodness. That's what I learned now from these first pictures. So the selection of the landing point in the next weeks is one of the most important things. It becomes not too hot on surface. Yeah, fascinating.

You mentioned Comet Gerasimenkov, 67P, that brilliant success at the comet, which we are still getting science out of. How does this mission promise to complement that? I mean, here we are at this type C carbonaceous chondrite asteroid. We were at a comet, which we also now know had water and organic materials. It certainly appears that at least in the last 10 or 20 years, we've learned a great deal more about these building blocks of the solar system. Yeah, but I think the most astonishing for me is that they all look different. If you look to the big planets they all look completely different yes and i mean completely

means they are really we can't we can't understand this different behavior really so up to now we have no idea the same with the moons of these planets imagine when nasa landed on moon in 1969 the first time at the end we had a feeling that the moon could be a bit boring object in a case. I mean, it's not boring. But imagine all the moons of all planets look that we would have given up, I guess. I mean, it's okay. It's not, yeah.

But they all look completely different. I mean, if you look to the icy moons on Jupiter, if you look the moons on Saturn, they all look different. I mean if you look to the icy moons on Jupiter, if you look the moons on Saturn, they all look different. So we have a variety, a large, large variety of all these bodies and the question is why? This for me is the biggest puzzle. Why they all look all different and now we have seen one comet in detail but this is only one and the question is does the next one look the same? We have no idea. The big surprise was the shape.

Now we have seen Ryugu the first time on June, and it looks like a diamond. It's regularly shaped, more or less. I mean, there are some graders in. Compared to 67P. Yeah, but it's a completely different shape. Why is that? So I think we have many, many information we get by visiting these kind of bodies. And we can only take out the selection of them.

And these are not by accident, but the selection is taken by many other questions like how we can reach them. Is it easy or not? But I think this is the most important. Then we have the types of the C and S type. But if we then select them, this is indeed by accident. And we have roughly 750,000 of these objects in our solar system.

And we take out one and the shape looks surprising. The question is, if we look for the next one, is it surprising as well? And I think this is the big puzzle. We need a larger sample. It's dangerous to do science on a small sample size. It's relatively, it's dangerous to say, but it's relatively easy to land on a small body. It's much easier than to land on a planet. easy to land on a on a small body it's much easier than to land on a planet so there was the idea of having these small landing systems that we can do it maybe repeat it having always this kind of

landing systems and then we can investigate and then maybe we can find more information of more bodies this is now the second time that we land on an asteroid. The information baseline is not as big as we would like to have. The history of 50, 60 years in space, 60 years, is that we learn by each of these missions and we get more questions by any missions as we had before. It's good and bad. The nature of science. Do you see any reason?

Do you expect to be surprised by what we learn about Ryugu? I hope so. No, I think, I mean, there's a lot of things we like to be confirmed of. I mean, we say, hey, this was a theory

and this is also nice to see. The theories are not completely nonsense. We will see a lot of new things. As we have seen it from Itokawa, the Japanese has found them. They brought back one milligram of material and detected more than 120 minerals in this one milligram. This was unexpected. This was unexpected. One would expect a small body like that has a more or less homogeneous material and is not a composition of many, many minerals. And this is what they learned there. So I expect many new information, many new questions.

Hans-Jörg Dietes of the German Aerospace Center, or DLR, talking with me at the Kospar Scientific Assembly. Back with Bruce in moments. Time for What's Up on Planetary Radio. The chief scientist for the Planetary Society is on the line once again. That's Bruce Betts. Welcome back. Thank you. Very, very exciting week, isn't it? It is. The time has come.

I've been talking about it, but now it's here. Mars opposition on July 27th, opposite side of the Earth from the Sun, and closest approach on July 31st. This is the closest approach since 2003, so therefore it'll be brighter and bigger than it has been, brighter than everything in the, every natural thing anyway in the night sky, except for the Moon and Venus, which is also up. So we got that going on. You can learn lots of details and all about oppositions and close approaches on our website, planetary.org, where I've got a blog talking all about the Mars opposition and closest approach, what else you can see.

But there's also a total lunar eclipse, which I also talk about in the blog. And that occurs, for those of you in most of Europe, Africa, Western and Central Asia, the Indian Ocean, and Western Australia. So not us. Sorry, Matt. Unless you want a road trip. I'm always ready for a road trip. But here's what's even super cooler is it'll be near bright Mars in the sky.

So you'll have reddish moon and reddish Mars hanging be near bright Mars in the sky. So you'll have reddish moon and reddish Mars hanging out near each other in the sky, which is not coincidental, as you can find out in my blog. And then also, so Mars is rising at opposition. It's rising around sunset and setting around sunrise. And so Mars is in the east in the early evening. And then if you just swing across the sky, across sky, you'll see Saturn looking kind of bright and yellowish. And then farther over Jupiter, super bright, usually brighter than Mars, but not right now. And then Venus, even brighter over in the west. And they nicely follow along a line, proving once again that we orbit in a

relatively flat solar system in terms of the big object orbits. It's exciting, man. It's really exciting. Go out there and look up, everyone. And Bruce's blog that he mentioned, this nice little Q&A, you can find it, of course, at planetary.org, where all of our great blog posts are. Awesome. We move on to this week in space history. 1971, astronauts first drive a car on the moon with Apollo 15 lunar roving vehicle, first one. Dune buggy.

Dune buggy. 1984, Svetlana Savitskaya became the first woman to spacewalk. Huh, I'll be darned. Okay. Move on to Random Space Fact! Sorry, I'm kind of excited today. At closest approach for the 2018 opposition, Mars will be 24.31 arc seconds in diameter. Now, ever since 2003, every opposition we get, the Mars hoax pops up saying Mars will be as big as the full moon, which of course is very, very wrong, but let's figure out how wrong.

The full moon has an angular diameter of about half a degree, or 1,800 arc seconds. So for the 2018 close approach, the full moon will be about 74 times larger in diameter than the maximum Mars disk size. Yeah. And you, you address this in that blog post as well, which I was glad to see. It's so true. All right, we move on to the trivia contest, still talking about Mars. And in this case, the reason why its brightness varies so much from one opposition to another. What is the eccentricity of the Mars orbit, which defines how non-circular it is, basically? How'd we do, Matt? I'm going to go straight to our winner,

because you already told me that he had this right, because I'm excited. He's in my old hometown, the place where I lived for 30 years or so. And that's Long Beach, California. Lucas Sabat or Sabate, he didn't give us the pronunciation, but Lucas said that this eccentricity is 0.0934, which means what? It's, for those who have taken your analytical geometry, trigonometry kind of stuff, it's how much is your ellipse squished, to use the non-technical term. So how much is your circle squished? And so if you're not squished, you have an eccentricity of zero. And the farther you get from zero, the more squishy it is. And Mars has a much higher eccentricity than Earth,

for example. Well, Lucas, congratulations. You're going to get that Planetary Radio t-shirt and a 200-point itelescope.net astronomy account. We have some other interesting stuff from Tony Knutson in little Stewartville, Minnesota, up there on Interstate 90, here's a random space fact for you. He says, if Mars's orbit was the size of a ping pong ball, you could imagine squeezing that ball in a millimeter and a half on the sides. Or, you know, if you prefer the top and the bottom, which I thought was pretty good. Yeah, that would be the equivalent of Mars eccentricity, I'd take it. I don't know how good his math is there, but I'll take his word for it. Norman Kassoon in the UK, a regular listener and entrant who always has interesting stuff for us. He says Mars experiences a dramatic change in atmospheric pressure because of its eccentric orbit.

Are you familiar with this? Yes. because of its eccentric orbit. Are you familiar with this? Yes. Mars, because of its higher eccentricity, it actually varies significantly in how much solar insulation it gets, so how much solar radiation it gets. It's a non-trivial variation, which changes various things on Mars, and it's much more significant than, say, for Earth, where we don't see much variation. Other factors, particularly the tilt of the Earth, vastly dominate. Just a couple more of these.

Russell Frizzell in Olympia, Washington, along with a bunch of other people, including Zoe Reinertz in Germany and Robert Laporta in Connecticut, they said that the eccentricity of Mars's orbit was a clue for Kepler to the natural laws of planetary motion. In other words, they helped him figure out that stuff goes around other stuff in ellipses. All right. Way to go, Mars. Way to help Kepler get a clue. And then a couple of other people, Jordan Tickton, Laura Dodd added, this eccentricity has been changing that one and a half million years or so ago, Earth years, it was pretty close to circular, but it's getting more eccentric every day, just like you and me. It is indeed. And that's why we, on very long periods, are getting closer approaches than we did in previous human history. Yeah, it's all in these big, long cycles that are driven by, primarily by Jupiter's gravitational influence on Mars. And in line with that, from Robert Klain in Chandler, Arizona, your and Bruce's personal eccentricities are quite endearing and one of the big reasons I

listen to the podcast each week. Oh, I thank you. I think? No, I'm pretty sure. With that, we are ready to start a new one. All right. Can't get enough Mars Close Approach. When will be the next Mars Close Approach when Mars is closer to Earth than in the 2018 Close Approach? When will Mars next be closer to Earth than in 2018? Go to planetary.org slash radio contest. And I want to be kind this week to all of the people who hear this program too late to answer the contest. We'll call this an experiment. Maybe we'll make it a regular thing, maybe not. But since some of you will probably be hearing about the Mars opposition and a close approach and the eclipse after it happens, we're going to give you more time to enter the contest this week. How

about we move the deadline out two weeks? That means that you will need to get us your entry by Wednesday, August 8th at 8 a.m. Pacific time, and you will have a chance to win a Planetary Radio t-shirt that you can check out at chopshopstore.com. That's where the Planetary Society store is. You can see all our cool stuff. And a 200-point itelescope.net account from that worldwide network of telescopes that anybody can use. 200-point account is worth a couple hundred bucks US. They have a brand new planning tool that you can see on their site. It's very cool. It helps everybody find lots of beautiful objects in the night sky and then examine them with the telescopes that are part of the network. So good on you, iTelescope. Cool. And with that, I think we're

done. All right, everybody, go out there, look up the night sky, and think if you put a T-shirt on a tank, does it become a tank top? Thank you. Oh, God. He's kind of proud of that one. I am speechless. I have nothing to add to this one. Yes. Except that a tank top would be wise to wear currently across much of the United States and the world. So stay cool, Bruce, and all the rest of you as well.

Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its members around the world. Mary Luz Bender is our associate producer. Josh Doyle composed our theme, which was arranged and performed by Peter Schlosser. I'm Matt Kaplan. Ad Astra.