Planetary Radio: Space Exploration, Astronomy and Science - Running Before the Sun: Astronomer Jay Pasachoff

Episode Date: December 6, 2016

No one is more excited about eclipses than famed solar astronomer and author Jay Pasachoff. He looks forward to the total solar eclipse in August of 2017.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Welcome again, podcast listeners. It's been a while since I've shared one of these special pre-show messages with you, but the timing is right. I got this message from listener Nicholas Panagasser last week out of Las Vegas. And you know how we love to get these special greetings or messages. We've got a field for that. When people will enter the contest or just want to write to us about anything else at Planetary Radio at planetary.org. Nicholas had this message. Now is the most important time for the public to show its support of space exploration and science in general. Donate when possible and always use the power of social media to share all the great content organizations like the Planetary Society provide us. Nick, thank you. Couldn't have said it better myself.

And your timing, as I said, is perfect because we are approaching the end of the year. And with that in mind, the Planetary Society has created the Planetary Fund. The Planetary Fund is going to accelerate our progress toward our four core enterprises, revolving around our four core enterprises. And what are they? Robotic space exploration, human space exploration, planetary defense, and the search for life. In other words, most of what we talk about on this show. And so it's very, very exciting stuff. And what is especially exciting is that during this year-end giving period, any donation, any gift that you make to the Society

at planetary.org slash planetaryfund is going to be doubled. It'll be matched by a very generous anonymous member, up to $100,000. So there's never been a time like this to donate, and there has never been a more important time to help us accomplish what we need to do to promote space exploration and space science in what promises to be a very challenging year, next year, 2017. You can support the fund as a whole, just, you know, make your gift, and we will use it wherever it's most needed.

Or you can designate your gift to any part of what we do, any of these enterprises, or even Planetary Radio. If you go to planetary.org slash planetaryfund and just scroll down the page, you'll see Planetary Radio listed there too. But honest, I won't be offended if you just do an undirected donation or if you pick one of our other great, great priorities. Thank you so much, those of you who are able to participate in this and see your donation doubled. And we will go on now to, I think, a pretty fun edition of Planetary Radio. Thanks, everybody, and happy holidays. Astronomer and astronomy educator Jay Pasikoff, this week on Planetary Radio.

off this week on Planetary Radio. Welcome. I'm Matt Kaplan of the Planetary Society with more of the human adventure across our solar system and beyond. A busy show this week as we welcome back the co-author of the magnificent astronomy textbook called The Cosmos, Astronomy in the New

Millennium, along with many many other books. Bill Nye has been following space developments in Europe, and we'll catch Bruce Betts just before he attends what may be the last critical ground test for the next light-sail spacecraft. With Emily off this week, I invited back Planetary Society digital editor Jason Davis. Jason, welcome back to the show, although we did hear from you last week when I played the audio from that first episode in that terrific Rocket Road Trip series, but it's good to have you here actually able to interact.

Yeah, good to be here. You can't get rid of me. Why would I want to do that? Wonderful series. Actually, I should say two series. want to do that. Wonderful series. Actually, I should say two series. Lots of credit to Casey Dreyer and our video guy, Merck Boyan, for the Rocket Road Trip series. But your Horizon Goal series also continues at planetary.org slash horizon goal, all one word. We've talked about it before, but it's been quite a while. You're headed toward doing the last post of this?

Yeah, we should have the next post up in about a week and a half, roughly, is what I'm hoping. It was a little more ready to go when things seemed a little more certain with the presidential administration, but that's all been kind of complicated now, and I've had to go back and do a little more research and work to try to put together this final piece on what we think, or at least what I think the future of NASA's human spaceflight program is going to look like in the next few years. You mentioned in the rocket road trip series, you actually say NASA is transforming itself around the space launch system, that big rocket, and the Orion capsule. Do you stand by that? That's a major statement to make about a behemoth agency like NASA. Yeah, I do.

And, you know, it sounds, on one hand, when I use that phrase, I always think, I don't want people to think I'm drinking the Kool-Aid, I'm doing Journey to Mars all the way, and I'm in NASA's camp. Objectively, I think you can say that. They really are, at least the centers that we visit really are transforming themselves. The signs are just everywhere. Massive infrastructure installations, kind of stripping these facilities to the bone, putting in new equipment. They really are. I think they've learned their lesson from the shakeout that happened in 2008 and are really

going full steam on this program. Now, the wild card is, is anything going to change? And you can already tell NASA is clenching their teeth and kind of clamming up and wondering, what will the next administration do? Will they change anything, make any major moves at this point? But I think NASA, just given the ability to just continue on its path, they're doing a good job and they really are transforming itself like that. Did you see the story that I discovered just this morning that there may be some changes in the first SLS mission, the first Orion mission to carry humans, which was, they were talking about it orbiting the moon. Now they're talking about sort of a

free return, as they say, where, you know, they wouldn't have to fire any rockets to make it back home. Yeah, the big question there is the exploration upper stage. SLS right now for its first mission, which is just an uncrewed Orion flight around the moon in 2018, that will use this upper stage called the interim cryogenic propulsion stage. Basically, it's an upper stage from a Delta rocket, United Launch Alliance Delta rocket. Now that's not rated to carry humans. So NASA's choice is, do we want to go ahead and build our big, powerful upper stage engine that we want for the future of SLS? Or should we try to human rate this interim stage? The consensus was it'd be much cheaper to just go ahead and build the upper stage rather than fiddling around with this other stage that they're using temporarily. But that makes everybody a little bit nervous.

Sending astronauts into space on top of a brand new second stage engine that has never been used, that's another, I use that teeth-clenching phrase, I wouldn't want to be around the moon relying on that engine to work for the first time in space. So they want to play it a little more conservatively, and that's kind of the middle ground they're coming to here, it looks like, where they'll first spend some time in these big elliptical Earth orbit profile to kind of shake out what they're doing there, and then maybe fire that engine and take them on this free return trajectory around the moon. So that way it gives them an abort capability.

If something goes wrong, they're still hanging out near Earth and can come back safely. It's all ahead, and with any luck, not too far ahead. And if you want to look back, go ahead and take a look at that Horizon Goal series at planetary.org slash horizon goal. Great work on that, Jason. We've only scratched the surface here. There is so much more available. Great fun doing that video series, the rocket road trip as well. Thanks. We had a lot of fun making it. so I hope your listeners really enjoy it if they check it out. That's Jason Davis, digital editor for the Planetary Society, my colleague there, and he will continue to follow human spaceflight. And are you on your way to SLO, San Luis Obispo,

today? Yeah, I am. I'll be heading out in a little bit for a light sail test coming up tomorrow. So I imagine we'll be talking about that soon as well. Absolutely. And I think we're going to hear about it from Bruce Betts, who will be up there later today as well. Thanks again, Jason. Thanks, Matt. Up next is the CEO of the Planetary Society. That's Bill Nye. Bill, we turn to Europe this week, beginning with the meeting last week of the member nations of the European Space Agency, ESA. Yeah, it's a big deal. They've agreed to fund ExoMars and to continue participating in the International Space Station until 2024. Now, everybody, it's 2016. I mean, it's almost 2017, but that's a long commitment. Seven-year commitment to funding this enormous

thing in space. It's cool. It's good to do. And then ExoMars is scheduled to launch in 2020. That's the rover, the European rover, right? Yeah. And it was 2018, I guess, but now it's going to be launching in 2020. And so will, it is presumed, the U.S. Mars 2020 rover. So maybe we'll make some discoveries up there and find life and change the course of human history. Is that all? It's just a thing for me. My disappointment, of course, is that because they just don't have enough money to go around, they canceled this new asteroid impact mission.

It looks like the LISA gravity wave mission, after the great success of the LISA Pathfinder mission. It has maybe, may not go up until the 2030s. That was a little sobering. Well, that's so far. You wait till we, our advocacy is done with. I'm hoping the Planetary Society can convince people that this is a worthy use of their intellect and treasure. There's been some upheaval over there, I say over there in Europe with the Brexit. And of course, there's big concern about the future of planetary science here because of our recent US election. very well funded, but it's not clear that planetary science will stay well funded because,

well, because you cut taxes, the government has less money, and there'll be less of this sort of thing, probably, because there is really no business case for exploring Mars. Selling tickets for people to go to Mars is a different thing from actual exploration. Anyway, that aside, people to go to Mars is a different thing from actual exploration. Anyway, that aside, the other thing that I found so interesting this week, Matt, this chief operating officer. Now, I, Bill Nye, rely heavily on Jennifer Vaughn, the chief operating officer of the Planetary Society. I mean, she pretty much runs the show. I'm along for the ride. But this guy, Vladimir Evdokimov, yeah, was arrested for fraud, $3 million. Just last week, there was another resupply mission to the space station that crashed. And apparently it was the second stage or the upper stage.

And so is that related? Are the crashes of rockets related to a guy arrested for fraud. Just think what the scandal would be if somehow someone in NASA was able to skim off $3 million. That's just inconceivable to us in the United States. It just shows you it is a different culture that runs the rocket business in other parts of the world. What a wild time, Matt. It's a wild time. Yes, it is. Thank you, Bill. Thank you, Matt. That's the CEO of the Planetary Society, Bill Nye the Science Guy.

If you studied astronomy in college, if you're an engineer who took a physics class, if you're an amateur astronomer or just a fan of the night sky, there's a good chance you've read something by Jay Pasikoff. The list of books he has written, co-written, contributed to, or edited is extraordinary. It was nearly three years ago that I welcomed Jay and colleague Alex Filippenko for a conversation about their brand new edition of The Cosmos, Astronomy in the New Millennium. Jay hasn't slowed down since. He is Field Memorial Professor of Astronomy at Williams College and directs the Hopkins Observatory there,

but is frequently traveling the world to conduct observations or share his research. I ran into Jay at the recent meeting of the American Astronomical Society's Division for Planetary Sciences in Pasadena. He accepted my invitation to sit down at the planetary radio table for a conversation that included next year's North American total solar eclipse. I don't think there's another person on our planet with more enthusiasm for eclipses than Jay. You'll also hear him mention the so-called black drop effect that has puzzled astronomers observing transits of Mercury and Venus

for more than 250 years. Follower of the sun, is that fair, Jay? I like to say I precede the eclipses rather than following them. They go thousands of miles an hour across the globe, so eclipse chaser is not a term that I like to use. You run ahead. That's right. You precess. Eclipse preceder. We're pushing eclipsophile these days. Let's get to the big event that I'm sure you're excited about next year. But initially, what's happening here at TPS? You said you have a poster. I know how to look at the sun. I'm basically a solar astronomer. But when things go in front of the sun poster? I know how to look at the sun. I'm basically a solar astronomer.

But when things go in front of the sun, then I know how to use the solar resources to observe them. So in particular, I got particularly interested for the transit of Venus in 2004. And we very carefully observed the two transits of Venus in 2004 and 2012, but we've been using transits of Mercury to explain some things about the transit phenomenon and what the black drop is that you see at transits of Mercury and Venus. Most recently, there was a transit of Mercury on May 9, 2016, that was largely visible from the United States. It's a seven-hour event.

The sun rose at the Big Bear Solar Observatory in Big Bear Lake a couple of hours east of here, east of Pasadena and up in the mountains. Do you know Claude Plymate up there? And Claude Plymate had things all set up.

And his wife, Teresa, arranged a talk for me for the group there. But Claude was very helpful. And we used the 1.6-meter solar telescope, which is a much better resource than had ever been used before on a transit of Mercury. We have absolutely fabulous videos and stills of this event. We were working in particular with Dale Gary and Bin Chen of the New Jersey Institute of Technology who run, from the scientific side, the facility now. So we have these very high resolution observations and we can follow Mercury going across the solar disk in front of the solar granulation, which we've sharpened with the

adaptive optics that we were using at the time. And then when it approaches the limb, we can see the black drop effect that we originally explained with spacecraft observations of the 1999 transit of Mercury, proving that it does not need to result from an atmosphere because Mercury, of course, doesn't have an atmosphere, whereas for Venus the black drop effect had been often said to come from Venus' atmosphere. So we were able to show that a couple of hundred years of statements about transits of Venus were basically wrong. We're still able to learn from these natural phenomena.

Yes, astronomy is wonderful, and we learn all these new things. I had a little conflict with my publisher, Cambridge University Press, about the new edition of my textbook, which is called The Cosmos. And the new contract they gave me somehow had a clause asking me to vouch that the facts were true. And I looked at this. I hadn't seen this particular clause before. I said, well, in astronomy, all the time we learn that so-called facts turn out not to be true after all. So I really can't sign this clause that all the facts are true. And in fact, I do have in the preface of various of my editions that don't believe

everything you read here. So in any case, they took it back to the legal department that eventually we got that clause struck out of the contract. I'm not surprised that they came around to your point of view. The big event that's happening next year, which I know you must be very excited about. In fact, you were just showing me one of your grandchildren using an eclipse viewer. We've got the big North American total eclipse coming. It's less than a year now.

One of the points we like to make is that this is such an exciting thing when you are in the zone of totality. And there are about 50 million Americans is that this is such an exciting thing when you are in the zone of totality. And there are about 50 million Americans who do live in this 60-mile or so wide band of totality that goes from Oregon to South Carolina. There are, of course, about 300 million others who live outside, and they don't really realize the difference between a total eclipse and a partial eclipse. Even if you have a 99% partial eclipse,

that still leaves it 10,000 times brighter than in the band of totality, and you don't see any of the interesting phenomena. So it's important to get outside during the eclipse, looking on a website or computer screen or a video screen, just doesn't do it at all, you miss the effect. There's a primal wonder in standing outside in the middle of the day when the earth goes dark around you, the quality of the shadows change about 15 minutes in advance, getting strangely sharper,

the light turns an eerie color, and then these very rapid events that will take place for about two minutes on August 21st, around 10, 15 in the morning on the West Coast and in the afternoon on the East Coast. We really want people to be outside. We are working in advance to properly educate the ophthalmologists and the medical professionals who often falsely warn people about hazards that are not as great as they claim. Often people get the mistaken idea that there are some strange rays that come out of the sun during an eclipse, which of course is not true. It's merely that most of the ordinary light is shut off, allowing us to see this halo around the sun, the corona,

that is up, it's up today, but it's behind the blue sky on a normal clear day. But I also want to stress the point that falsely warning people for so-called security, safety, it can be counterproductive because the eclipse is so glorious people who are banned from seeing the eclipse will soon meet a friend or relation who saw the eclipse and says wasn't it glorious and these kids will say oh no my teacher locked us in the room or the school board kept us from seeing things because they said it was hazardous

and the other person will say what do you mean I watched it, it was great, it was the most fabulous thing I've seen in my whole life. And then the next time there's a warning for safety or getting vaccines or having safe sex or doing all the warnings that we want people to follow, they won't respect the authorities that are putting out these warnings. So it's important to give accurate information. And we are trying now in advance of the 2017 eclipse, knowing the history of false warnings to try to get accurate information out.

Why is it so important to you that children, even very young children, be able to participate in this? Well, I was inspired in my professional interest. I remember in high school, the Hayden Planetarium in New York, I know for eclipses, I saw one the first two weeks of my freshman year at Harvard. There happened to be an eclipse over Massachusetts, but I did start my younger daughter out at the age of six months and the elder one at the age of two and a half years. But so often the attitudes of kids towards science is formed in those early years. This granddaughter whose picture you saw looking from the Caltech campus at a partial eclipse that was here in 2014, she's going to

afternoon program once a week on science and we get a report of the wonderful things they've seen. And they're just inspired by this, and they can be inspired to go on. So we want to get the kids early. Well, first of all, we want them to know that the sun is not harmful. There are no special rays coming out of the sun. And we want them to know that there are interesting people called scientists who do interesting things. Astronomer and author Jay Pasikoff will tell us more in a minute.

This is Planetary Radio. Hello, I'm Robert Picardo, Planetary Society board member and now the host of the Society's Planetary Post video newsletter. There's a new edition every month. We've already gone behind the scenes at JPL, partied at Yuri's Night, and visited with CEO Bill Nye. We've also got the month's JPL, partied at Yuri's Night, and visited with CEO Bill Nye. We've also got the month's top headlines from around the solar system.

You can sign up at planetary.org forward slash connect. When you do, you'll be among the first to see each new show. I hope you'll join us. Hi, I'm Kate. And I'm Whitney. We've been building a youth education program here at the Planetary Society. We want to get space science in all classrooms to engage young people around the world in science learning. But Kate, are you a science teacher?

No. Are you? Nope. We're going to need help. We want to involve teachers and education experts from the beginning to make sure that what we produce is useful in your classroom. As a first step, we're building the STEAM Team. That's science, technology, engineering, arts, and mathematics. So teachers, to learn more about how you can help guide this effort,

check out planetary.org slash STEAM Team. That's planetary.org slash STEAM Team. And help us spread the word. Thanks. Bye. Bye. Welcome back to Planetary Radio. I'm Matt Kaplan,

astronomer and self-proclaimed eclipse preceder. Jay Pasikoff has returned to our show. Let's bring it back to DPS. Just before we started to record, you were on the phone setting up a lunch, which you said is a regular thing you do at this meeting? Well, as I said before, I know how to look at the sun with the various assets of telescopes around the world. A couple of decades ago, I discovered in talking to one of my graduate school friends, Jim Elliott, who discovered the rings around Uranus, that my equipment for studying the sun at eclipses, very fast readout, accurate imaging devices, were the same that he was using to study rings by so-called

occultations, when something hides a star, for example, except he was not using a filter at all to get as much light as possible, and I was using special filters for the solar corona. So I started working with him to take my additional apparatus along to these events. After the eclipse some years ago in Indonesia, there was an occultation scheduled by Neptune. At the time, we were looking for rings around Neptune. And then in 2002, there was a major occultation,

and by major, I mean an especially bright star that was to be visible from Mauna Kea in Hawaii, and I was assigned one of the telescopes there, and we used all the telescopes on Mauna Kea for this wonderful occultation of a star by Pluto. And what you then see is that Pluto blocks the starlight, but the starlight does not wink out immediately because Pluto has an atmosphere. So it weeks out gradually and sometimes with little spikes of intensity that come from a focusing in Pluto's atmosphere. So long before the New Horizons spacecraft, dear, we have been

studying Pluto's atmosphere. There are three groups of people around the world who are mainly working on this kind of thing. My group from Williams College is combined with my colleagues at MIT in the Lowell Observatory. And then the group at Southwest Research, SWERI, which runs New Horizons, has their occultation people. And sometimes they've previously been at MIT for graduate school, for example. They've previously been at MIT for graduate school, for example. And then Bruno Sicardi and Thomas Wiedemann had a group of French astronomers who very successfully look at occultations around the world. A year ago, there was one of a 12th magnitude star, which by our standards is bright.

Usually the stars are 50 or 100 times fainter than that. And I was observing with one of our pieces of apparatus. Incidentally, following this great success in 2002, we've had a series of grants from NASA's planetary astronomy for support of our work, which included getting identical systems, three for MIT, three for Williams. Congratulations. Thank you. And so we had one of these systems on a one-meter telescope at the Mount John University Observatory in New Zealand,

and it was such an important event that NASA flew its instrumented airplane, SOFIA. SOFIA, as listeners of this program know, we've flown on SOFIA, and I know about that trip to the Southern Hemisphere. Well, so we had coordinated results. We have a pair of papers submitted to Icarus, the planetary science journal, and I'm the lead author on the ground-based observations. Dr. Amanda Bosch from MIT is the lead author on the SOFIA paper, and Dr. Mike Persin, who is also here, the lead author of a poster that's going to be a paper about what's called the central flash. When you get right in the middle, which required maneuvering for SOFIA to be there,

there's focusing around Pluto from not just the image bent on one side or the other, but in the middle. The middle of Pluto is right smack in front of the star. The atmosphere focuses some light around. You get a little brightening in the center. And that enables us to see deeper into Pluto's atmosphere than we could otherwise. So we have these great results that we're busy talking about. And once a year at DPS, people from the three groups together have lunch,

and I've organized that for today, where we're up to 16 people for lunch today. Is there any replacement for actually being able to sit down with these folks over a meal or mix with them, have a beer someplace, at a meeting like this face-to-face? I think it's very important to get together face-to-face. There really are new ideas, new methods that get generated with these face-to-face imagings. And we can talk on Skype or send emails back and forth, but it's no substitution to actually seeing each other. There's a lot of science that gets developed. There is, of course, a rivalry for telescope time, often among the three groups, but we want to do it in a friendly manner. And we look forward to seeing our colleagues from all these three rival groups at lunch today.

Just one more question for you. When was the first edition of Cosmos? Well, the first edition of my book, which is actually 17 editions ago, was called Contemporary Astronomy. When I first went to Williams College as a professor, the books then had too much about instrumentation and the orientation of the sky and not enough about modern science. And so I developed the idea of having a textbook. It was first called Contemporary Astronomy that brought in the modern science earlier on. And that's gone through several different versions. And we brought in Alex Filipenko from the University of California at Berkeley, who's an expert on supernovae and cosmology, now to work with me on this latest version, which is called The Cosmos Astronomy

in the New Millennium. And he has been on the show to talk about the book. When was that first edition of what led to Cosmos? Do you remember what year it was? Well, my very first edition was copyright 1977 of Contemporary Astronomy. And then two years later, some professors preferred to teach the planets ahead of stars. So there was one called Astronomy from the Earth to the Universe that went through six editions. But my point is, almost 40 years now,

has to be hundreds of thousands of students who've had their introduction to the universe because of this book that you began, and now Alex Filipenko co-writes with you. That has to be satisfying. Well, it is very satisfying. Another satisfying thing, I got a letter, an email about a month ago from a woman who said she's a new professor at the University of California. And just to let me know that here was the book that started her off in astronomy. And she sent a photograph of my Peterson First Guide to Astronomy that she had used decades ago.

So it really is wonderful when you can inspire a student. I know that many people have been inspired by eclipses. Tycho Brahe was one of those back in the 16th century. And I'm sure we'll get a lot of kids inspired by seeing this eclipse that's coming this summer, if we can get them out watching it. And where will you be? I will be at Salem, Oregon. My colleague Jay Anderson is a meteorologist.

I'm actually doing a Peterson First Guide to the Atmosphere with him. And he has compiled decades of satellite imaging of the Earth, looking down for cloudiness statistics. And you can see in his coda colad map which and you can get them on eclipse o file EC LI P s o ph il e.com and you can see that the western United States have better cloudiness it's more favorable cloudiness statistics than the middle or eastern part of the country instantly I do have a website to link all this. It's just eclipses.info, E-C-L-I-P-S-E-S dot info. And we link to all these other sites right there just to make a one-stop shop for people who want eclipse information.

Jay, I look forward to joining you along that path of totality less than a year from now. Thank you so much. It's been a delight talking with you. It's been a delight talking with you, too. Thank you for inviting me to discuss. Williams College astronomer and author Jay Pasikoff. We talked at the American Astronomical Society's Division on Planetary Radio. We've got Bruce Betts, the Director of Science and Technology for the Planetary Society, standing by. Before we get into the usual What's Up content, you, like Jason Davis,

are headed up to San Luis Obispo today. Tell us what's going on. We are going up to Cal Poly San Luis Obispo to do what should be some of the final testing on the LightSail 2 spacecraft. We will be doing a simulation of key flight events from opening of the solar panels to deployment of the solar sail. Although we will be deploying the booms, we won't actually deploy the sail material this time because we're trying to limit the number of times it gets unfolded and folded, but we'll be testing all the major systems and simulating spaceflight as closely as possible in an Earth environment. And if all goes well, what happens after this? If all goes well, we will deliver within the next few weeks the spacecraft to Air Force

Research Laboratory in New Mexico. And there it will meet up with Georgia Tech's PROX-1 spacecraft and light sail to fits inside PROX-1. PROX-1 gets deployed when in space and then we get deployed from Prox-1. We basically pass it off. If we find issues, then we fix them before we deliver and test again. All right, fingers crossed. Let's go up to the night sky.

What's up there? Well, we've got the Geminid meteor shower coming up. This is typically the best meteor shower of the year, peaking the night of December 13th and 14th, but good a few days before and a few days after. The challenge this year is it's a nearly full moon, so that's going to make seeing meteors tough. You'll be able to see the brighter ones, but not the usual numbers, presumably. It's still worth a look as the brighter ones will still be there. Meanwhile, while you're out there, if you're looking in the early evening, check out Venus, super bright, low in the west.

And to its upper left, much dimmer and reddish, is Mars. And in the predawn east, we've got Jupiter looking super bright. We move on to this week in space history. It was 1972 this week that Apollo 17 launched and landed on the moon. This was the last landing of humans on the moon. Yeah, rumors about an Apollo 18 mission. To the contrary, rumors. I should say myths. Ridiculous. Fake news. That's what that was. Indeed it was. On to

Random Spooky News Guys. Apollo 17 returned about one of me, or about 110 kilograms, about 244 pounds of lunar rocks and dirt, the largest return by any single mission. Very impressive. That's quite a pile of rock. It is indeed, and most of it's still hanging out in Johnson Space Center, and scientists still analyzing it with new technology as the years go by. Yeah, one of the big thrills of my life early this year when I got to stand on the other side of glass from some of that dirt. You know, we should put you on the other side of glass at the Planetary Society. You'd be better for everyone.

Yeah, yeah, yeah. Go on. Yeah, yeah, yeah. Go on. Yeah, yeah, yeah. All right. Trivia contest. We asked you, what type of geologic features surround the residual

north polar cap of Mars? How'd we do? Very, very big response. And I suspect it had everything to do with the very special prize that we're going to be awarding this week.

And that is that Pluto globe. Brand new globe of Pluto based entirely on the images gathered by the New Horizons mission. Comes to us from Astronomy Magazine. It really is impressive, and it's going to look really good on some shelf, I hope, to Rob Connolly. Rob Connolly in, get this, chosenbyrandom.org, San Luis Obispo, California, first time winner. Total coincidence, I swear. He says it appears... Sorry, I don't have it to deliver.

You could have dropped it off. You're right. He says, it appears from my travels in Google Mars, the North Residual Polar Cap is surrounded by sand dunes. Perfect. There's a huge sand dune sea that surrounds the Residual Polar Cap in the north on Mars. Well, Rob, the ways of random.org are mysterious, but they work for you. And you'll be getting that beautiful globe of Pluto. Thank you very much to the folks at Astronomy Magazine for providing that. As always, we've got some other interesting stuff.

From Kevin Hecht, a regular in Pleasant Plains, Illinois. He says, at least I hope it's dunes. He said, we found dunes on Pluto and Titan and Indiana. He said, all the cool places have dunes. I had to include this just because I'm so impressed by it. John Bethauser in San Francisco. Inexorable changes in climate and seasons are hidden within the sublime and beautiful telescopic plateaus on the Martian ice caps. How thick the layers of time are within this chilly stratigraphy may be revealed by HiRISE and its companions. Him write good. It'd be good.

Davy Van Ness in Rotterdam, Netherlands. He also said Sam Dunes said the main ring of Dunes is apparently called Olympia Undae or Undae. He said this was a fun one to figure out. Reading Martian maps with Latin feature names is like trying to find a hotel in France pre-GPS. A lot of comments related to two other topics, at least one of them fictional. I'll let you guess which one. Michael Unger, Vancouver, British Columbia, said sand dunes spice. Lots and lots of dune references from many people this time, and a lot of references to a certain guy who lives at the North Pole here

on Earth. Jenny King in Bailey, Colorado was one who made a comment about this. She talks about the water ice and dry ice or CO2 ice at the North Pole. The Earth's North Pole, she says, on the other hand, is located in the midst of constantly shifting sea ice or possibly in the midst of a workshop belonging to some corpulent time-bending wizard. shop belonging to some corpulent time-bending wizard. I don't want to offend Santa this close to the big day, so we'll leave it at that. He knows you've been naughty. That's what I'm afraid of.

All right, what do we have for next time? For next time, we go back to Apollo 17. What did Gene Cernan, the last person to walk on the moon as part of Apollo 17, say before he entered the lunar module for the last time? So his last words while outside a spacecraft and on the moon. Go to planetary.org slash radio contest. I love that. you'll get a Planetary Society rubber asteroid, a 200-point itelescope.net account, that international nonprofit network of telescopes all over this planet, and we've got another copy of Extranaut,

the game of solar system exploration from Dante Loretta, the principal investigator for the OSIRIS-REx mission that is on its way to an asteroid right now, Asteroid Bennu. And it's this great game that we talked about last week, this Good Housekeeping Game Award winner for 2016. You can win it. And with that, I think we're done. All right, everybody, go out there.

Look up the night sky and think about shovels. Thank you, and good night. You can dig it. That's Bruce Betts. He's the Director of Science and Technology for the Planetary Society. He's digging it now. Who joins us every week here for What's Up. Planetary Radio is produced by the Planetary Society in Pasadena, California,

and is made possible by its transiting members. Danielle Gunn is our associate producer. Josh Doyle composed our theme, which was arranged and performed by Peter Schlosser. I'm Matt Kaplan. Clear skies.