Planetary Radio: Space Exploration, Astronomy and Science - Pluto Amazes!

Episode Date: October 20, 2015

Hal Weaver is a very happy Project Scientist. His New Horizons spacecraft has shocked his fellow researchers with magnificent images and data. He shares the excitement this week.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Pluto, we hardly knew you, this week on Planetary Radio. Welcome to the travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. Join me for an ecstatic conversation with Hal Weaver, project scientist for the New Horizons mission that has brought us a Pluto and neighbors that have wowed the public and shocked scientists. Bill Nye pays tribute to his buddy Neil deGrasse Tyson,

and Bruce Betts will tell us what we can see in a busy night sky. You might also win Bill Nye's personalized greeting for your voicemail in the space trivia contest. With some of the very latest news from Pluto and Charon, we go to senior editor Emily Lakdawalla. Emily, before we get into the biggest news from Cassini, another flyby of Enceladus, you've got headlines from elsewhere in the solar system. Let's start with Mars. We just had the ninth hole drilled on Mars by Curiosity, which is not very much considering how far we are into the mission, but it's only been 18 sols since the eighth hole, so they really are ramping up the pace. It's another drill hole that shows that Mars is red

on the outside and gray on the inside. I'm looking forward to the more detailed scientific results from that one. All right, just turning that red planet into Swiss cheese now. Let's hope so, anyway. Let's go much farther out to New Horizons. Of course, we'll be talking about that mission and what it has discovered at Pluto in just a few seconds with Hal Weaver. What is the latest that you've seen? Well, New Horizons releases new captioned images every Thursday and then all their raw images on Fridays. And the Friday releases contain

some really bizarre landscapes with these holes, these pits in the terrain in both Pluto and Charon, which was just fascinating. And it probably has something to do with volatile gases evaporating and leaving behind these pits, but it's still extremely strange looking. It was really exciting to see last week. You have a blog up from last week, October 13th, Charon in 3D. But let's go to a much more recent one that you just posted on the 16th at planetary.org.

And this is this latest flyby of Enceladus by Cassini. Some pretty spectacular images. Yeah, you know, this is Cassini's 20th targeted flyby of Enceladus. You'd think there wasn't a whole lot of new terrain to see. But as a matter of fact, the seasons change very slowly at Saturn, and we have really high summer sun now striking the North Pole, which is not something Cassini's been able to see before on most of the poles of most of the moons. And so they're still mapping new terrain and have these gorgeous images of this heavily cratered terrain that also has lots of fractures crisscrossing it. It's just a fascinating landscape.

The most striking of these, at least to me, is the second one down in your blog, these, at least to me, is the second one down in your blog. And it's this amazing image of these chasms snaking among the craters. Wow, this is really beautiful. That one's shot right across the North Pole. And it's just odd. You know, there's a lot of craters, which tells you this is very ancient terrain. But all of it is cut by all of these fractures, which have to be more recent. And it's really quite a puzzle to understand how we can have ancient terrain that is so chopped up by all these tectonic features. All right, what's ahead for Cassini at Enceladus? Well, there are two more flybys actually this fall,

and then that's it. We're getting very close to the end of the Cassini mission. The spacecraft will plunge into Saturn in 2017, but we're almost at the end of its last equatorial phase, which is when it orbits on the ring plane and can see icy moons up close. So we're getting very almost at the end of its last equatorial phase, which is when it orbits on the ring plane. It can see icy moons up close. So we're getting very close to the end for Cassini's images of icy moons. But not the end of planetary exploration.

In fact, I know that you are headed to a meeting to discuss JunoCam, the sort of, what, consumer camera on that mission that will arrive at Jupiter pretty soon. That's right. It will be very soon. It'll get to Jupiter, take amazing new images of Jupiter from top-down and bottom-up perspectives that we haven't had from spacecraft before. It's going to be really exciting. Emily, have a great trip, and we'll look forward to reading about that and much more in upcoming posts to your blog. Thanks again. Thank you, Matt. She is our senior editor, the Planetary Evangelist, and a contributing editor to Sky and Telescope magazine, Emily Lakdawalla.

And now let's talk to the CEO of the Planetary Society on the virtual eve of its 35th anniversary celebration, Bill Nye. Bill, many of our listeners who catch this show will be doing so after our celebration of the 35th anniversary of the Planetary Society. Nevertheless, it's still a few days away as you and I speak right now. I'm very excited about, among other things, the participation of, I think he's your good friend, Neil deGrasse Tyson. Yes, he is. Neil has worked so hard the last few years to engage people on social media, especially on Twitter.

And he's been successful. Being scientifically literate is cool now. That's true. Nerd is hip. And Neil's a big part of that. So the Planetary Society is giving him the Cosmos Award. And we've given this to Paul Absel, who's WGBH in Boston's produced every big time public broadcasting show you can think of. We gave it to Stephen Hawking, Jim Cameron, James Cameron, and now it's going to Neil Tyson. So it's a big deal.

For those of you who still have a few minutes, get out to Pasadena for our big celebration on Saturday night, the 24th. We'll have the 35th on the 24th, Matt. It's a deserving thing. The trophy is very cool. It looks like a big planet, Saturn, a planet that Neil is very fond of because it's got rings and is beautiful. And so we're going to show him a good time. I'm looking forward to a great time.

We've got the dedication of our new headquarters, too, and the appearance of people like Andy Weir of The Martian, who I will have as my guest on next week's show. He's done a great thing. The Martian is so popular as part of the same movement that Neil has worked so hard to cultivate. This idea that being scientifically literate, that science is cool, and being a nerd is not a bad thing. This Cosmos Award is celebrating Neil's work to advance science writ large for everybody in our society. We're really honored to be giving it to him. It's going to be a great party, Matt. The 35th anniversary. This is Carl Sagan's legacy. Bruce Murray, head of JPL, his legacy. Lou Friedman, orbital mechanician, working to get a mission to Mars with humans

orbiting in 2033 make sure this mission to Europa the moon of Jupiter with twice as much seawater as we have here on Earth and we want to get that Mars 2020 rover to have certain audio equipment and we'd really like it to have

an astrobiological focus it's an exciting time, Matt. Much to look forward to. I'll see you in Pasadena, Bill. See you in Pasadena. Thanks, everyone. That's the CEO of the Planetary Society, Bill Nye, the science guy. In a moment or two, Hal Weaver of the fantastically successful New Horizons mission.

This time we turn from the principal investigator to the chief scientist. Hal Weaver of the Johns Hopkins University Applied Physics Lab, or APL, is the project scientist for New Horizons. He has been in the planetary science game for more than 37 years, but wait till you hear him turn into a little kid marveling at his mission's revelations. It's fair to say that Hal's reaction is no different from the members of the science team he leads or thousands of other planetary scientists around the world.

Hal joined me a few days ago for a quick review of what's been seen so far, mostly of Pluto and its companion, Charon. Hal Weaver, merely congratulating you on this spectacular mission with these dazzling images just doesn't seem like a strong enough way to start this conversation, but nevertheless, congratulations to you and Alan and the rest of the New Horizons team. Thank you very much, Matt. Really, it has been almost like a dream for us as well. It's just been mind-blowing how successful New Horizons has been. The encounter just ran perfectly.

And now, the funny thing is, you know, most of the world's attention was focused on July for the flyby, but the science team, it's really just starting for us right now. Yeah, this is, the hits just keep on coming. Those, I already said dazzling, those jaw-dropping images of Pluto and Charon, they may be the best planetary science pictures of the year, and that's with a lot of great competition this year from all over the solar system. Did any of you suspect that these would be quite so spectacular? Well, you know, as you know, this was the initial reconnaissance of objects in the Kuiper Belt.

We didn't really know what to expect. A lot of us thought that Triton, the largest moon of Neptune, was our best bet for something similar to what Pluto would be like. There are a few similarities with Triton, but really most of what we're seeing has been a total surprise. It's just going to be fascinating to do the comparative planetology over the next year as the data roll in. I mean, we only got a snippet by less than 5% of the data coming in during the actual encounter period in July, ever since Labor Day. You know, Labor Day weekend, in fact, was when we first started streaming back the losslessly compressed data because, you know, we only had the JPEG lossy compressed data during the encounter week. And the quality is so much better with the

losslessly compressed data that we just started downlinking Labor Day weekend. And, you know, it's funny, we did anything but take that Labor Day weekend off because the images that were coming down were so spectacular. All of us on the science team were sitting at our computers as soon as the data were downlinked from the Deep Space Network and showed up at the Mission Operations Center and then at the Science Archive in Boulder. As soon as those data become available, we were jumping all over them and then just buzzing over the internet saying, oh, my gosh, what the heck is this? And then the following week, you know, to see that panoramic view from MVIC, you know, our color camera, Pluto just after closest approach.

I felt like I was sitting there on the surface of Pluto. It was just amazing. That amazement wasn't, of course, as you know, just amongst yourselves on the team. Anybody who regularly listens to this show knows that these images and the data are going to be trickling in for many more months. It's something Emily and I, Emily Lochte-Wall and I have talked about many times. And, of course, she continues to write about. Remind us of why it's going to take so long for all of this, this massive amount of data to be returned? Yeah, well, the basic reason is because the spacecraft is so far away, more than 3 billion miles from Earth.

We have a 2-point, well, we have about a 7-foot antenna, 6.9-foot wide antenna. And even though we have very advanced telecommunication system on the spacecraft, X-band transmitters, we have two of them. Still, they're only transmitting at roughly 24 watts. It's amazing to me even that we can communicate at all, right? Yes, absolutely. We're away with this little antenna beaming something towards the Earth. We point towards the Earth. Fortunately, we have these over 200-foot-wide antennas back on

the Earth that can, it is just amazing what they can do, the Deep Space Network, NASA's Deep Space Network. But the fastest that we can transmit and reliably detect it at the Earth is 2 kilobits per second, 2,000 bits per second. And we have images that have many megabits, tens of megabits, it just takes a long time to get all those transmissions back to the Earth. And we are prioritizing, of course, what we think is the juiciest data we're sending back first. Since the second week of September and through October, and as we finish up this calendar year, most of what we think are the best data will be played back and sent back to the Earth. But it is going to take a long time to get all of the

data from that encounter week, seven days prior to closest approaching the two days afterwards, the so-called core load, the encounter load. We're still sending data back from that period all throughout this calendar year. And then we had some stuff that we put on the recorder that we couldn't quite have enough time to get it down prior to the encounter. This is what we call our compressed forward data. We're sending some of that down as well. In order to get all of those data from those nine days, that whole entire nine day period really is going to take us until next September or October. Hats off, of course, to those magicians at the DSN.

Speaking of Emily, Emily Lakdawalla, she wanted me to thank you for sharing the data from the LORI instrument camera on the RAW website. And she asked me to ask you, when is the first formal archive quality data release planned for and what might it include? We're happy to share the LORI images every single week as we get more data coming in. You know, we have a group here at APL. LORI was, you know, built here at APL. We're reviewing those images and posting them as soon as they come in. As of every Tuesday afternoon, we'll post those on that following Friday. And sometimes we have a little commentary associated with it if there seems something funny in the data or if

the stuff that's automatically produced doesn't quite do it justice. Like sometimes the images will look faint, but there's really something there when you look more carefully. So we do that every week as data arrive. But as far as the deliveries to the planetary data system, the first formal delivery I think is – you know what? I need to check on that, Matt. I put you on the spot. Yeah. I'm sorry. I should have known that that question was coming.

Everybody's anxious to get it, you know, but I just don't remember off the top of my head. Not a problem. Let's go ahead and move on and sticking with those dazzling images for a bit. It's that topography that I'd like to start with. Incredibly varied and so dramatic. Well, you already said everybody's sort of jumping around when they see these images. What do you think of it? Yeah, I know they really are jaw-dropping. These giant ice mountains, the mountain ranges are one aspect of the things that are dazzling, but oh man, just the chaotic type terrain that's on the western side of Sputnik Planum, It's on the western side of Sputnik Planum that sort of reminiscent of the chaos regions that we see on Europa. But even on a larger scale, it seems like things on Pluto and Charon as well are even on a bigger scale than what we've seen in other planetary environments.

Possibly because the gravity is so much weaker. For example, Pluto's surface, the gravity is about one-sixth of what it is on the Earth. And so maybe you can blow things up by a factor of six. Similarly to what you see on a cometary surface where the gravity is so weak, you can have these spires of hundreds of meters high, even though there's hardly any strength involved in the material. But they can be maintained because the weight of the stuff is much less. And maybe similar things are true on

Pluto's surface. You can actually maintain very large structures because the weights are relatively small. Maybe that's one answer for why we're seeing such spectacular but very large-scale features. We do have these snake-skinned kind of regions in what are called the dorsa. Very large, long, linear features. There's evidence of the glacier flow in the Sputnik Planum region. But even in the highlands to the east of Sputnik Planum, it looks like there's evidence that the volatile material that had condensed in that region but now is now flowing back into Sputnik Planum. You know, you see these channels. Just the variety of geomorphology is mind-boggling.

Does that possibly explain these spectacular canyons that rival the Valles Marineris system on Mars that you've revealed on Charon? Yeah, I know. And Charon, I mean, Charon looks like it's been busted open or something. Yeah, yes. You know, at some points in its past, you get this thing just encircling near the equator the entire dwarf planet. It is really deep and it is really wide, the chasm. dwarf planet. It is really deep and it is really wide, the chasm, exactly what's going on and how old that is, I think, are TBD. Are we any closer to understanding those gorgeous red patches on both Pluto and Charon? Yeah, I mean, we're starting to get back more and more compositional

information from the LISA instrument, our near Infrared Spectral Imager. That's actually the biggest data hog among the instruments on New Horizons. And it's because there's so much information there. When you take more than 60,000 footprints on Pluto's surface in multiple wavelengths, 256 wavelengths, that's just a lot of information. And it takes a long time to get those data down, but we're starting to get it down. But it is a complicated instrument. And making sure that we don't misinterpret those data takes careful analysis, but we're starting to tease out a bunch of things. You know, we found places on Pluto where there's clearly exposed water ice.

But the fact that there's so much methane around and that's such a strong absorber in the near-infrared spectral region being sampled by LISA makes it difficult to tease those out. But then the very darkest regions where there's less methane, exactly what that material is, still working that. New Horizons Project Scientist Hal Weaver will return in a minute. This is Planetary Radio. Casey Dreyer here, the Planetary Society's Director of Advocacy. The New Horizons Pluto encounter was NASA at its best. But did you know that it was almost canceled twice? It was saved by thousands of space advocates who wrote and called Congress nearly a decade ago.

Today, more missions are threatened by budget cuts, including a journey to Europa and the Opportunity rover on Mars. You can learn more at planetary.org slash stand-up. Pluto was just the beginning. Hey, hey, Bill Nye here. I'd like to introduce you to Merck Boyan. Hello. He's been making all those fabulous videos, which hundreds of thousands of you have been watching.

That's right. We're going to put all the videos in one place, Merk. Is that right? Planetary TV. So I can watch them on my television? No. So wait a minute. Planetary TV's not on TV? That's the best thing about it. They're all going to be online. You can watch them anytime you want. Where do I watch Planetary TV then, Merk?

Well, you can watch it all you want. Where do I watch Planetary TV then, Mark? Well, you can watch it all at planetary.org slash TV. Welcome back to Planetary Radio. I'm Matt Kaplan. I hope all of you have seen and been appropriately dazzled by the flyby images of Pluto and Charon returned by the New Horizons spacecraft. Those images and other data will continue to trickle back to us across 3 billion miles for months. What has already been revealed will keep scientists busy for years. Project scientist Hal Weaver told us before the break about the fantastic colors on the surfaces of these distant worlds. Researchers have some initial thoughts about the chemistry behind them. I saw a picture of some little vials of stuff that somebody has been synthesizing down here,

and it's been given this name of Tholins. Yes, Tholins. That came originally out of Carl Sagan's lab and Vishun Kare, who worked with Carl for so many years, and then he moved over to the Ames Research Center and has been working for many, many years with Dale Cruikshank, one of our co-investigators. And Dale put together a bunch of vials of different kinds of tholins. Depending on exactly how you mix them together, these are hydrocarbons, heavy hydrocarbons that are produced by radiating either with ultraviolet light or cosmic rays or charged particles in original starting ices that have molecular nitrogen, methane, and carbon monoxide.

You take an original ice of that composition, which we know exists in the Sputnik-Planum region. In fact, it's just a giant sheet of molecular nitrogen ice mixed with this impurities of methane and carbon monoxide. But if we know that if you hit that kind of material with charged particles or ultraviolet light, that you break the bonds and reform this complex hydrocarbons, and exactly on what the chemical mix is, and you throw in some hydrogen cyanide, which we know isn't Pluto's atmosphere, you get all kinds of different kinds of heavy hydrocarbons

that are generically termed tholins. And depending on exactly what the chemistry is, you can get different colors. Generally, they tend to be kind of reddish, but you can get gray and yellowish. And you produce those in the lab. And when you look at the spectra from those things, they seem to mimic what you see on Titan, Saturn's largest moon. And we're in the process of comparing those Tholan spectra to what we're seeing on New Horizons. But we're just at the infancy of doing the detailed analysis. You mentioned the atmosphere that hugs these little worlds, or at least Pluto. It was just yesterday that I saw the blue sky.

I mean, really, a blue sky? Pluto has a blue sky. I mean, it's been amazing. We finally just got down last week. The color data from after we passed by Pluto and now look back, so you see just barely the crescent of Pluto illuminated by the sun, but now you see a haze all around Pluto. We saw the haze before in panchromatic light through all visible wavelengths, but now when

we look at the individual colors, that stuff is blue, just like what we see when we look at the blue sky on the Earth. And we think that this haze, this stolen haze that scatters, preferentially scatters blue wavelengths stronger for a reason that we're still trying to determine. But certainly the data tell us that we have this blue haze surrounding Pluto. And it's structured. I mean, you can actually see layers of it. That's been one of the big surprises is how strong and how highly structured that haze is. And our atmospheric scientists on the team are just busily cranking through those data and trying to come up with explanations of exactly what's producing it. It's going to keep people busy, I'm sure, for a very long time. You really do sound like a kid

in a candy store. I don't want to miss any great science that you would want to tell us about. What else have you been picking up, even if it's not fully understood yet? Yeah, well, you know, we're starting to get our resolved images of the small satellites as well. And it seems to be, you know, we see a couple of what look like impact events on these small satellites. And also it looks like in the case of Nix, we even see color variations over the surface. And in fact, in the impact crater on Nix, it looks to be a different color, more yellowish or reddish than the rest of the surface, as if we're excavating material. You know, once again, pointing towards an impact event. But this is basically in its initial phase as well.

And we're all on the science team looking forward to the Division of Planetary Sciences meeting that we have coming up in early November. That's going to be our first real opportunity to present to the community these initial results and our first attempts at the interpretation. And we are looking forward to the feedback that we'll get from them. We have the whole day, essentially, the morning anyway, set aside for Pluto plenary talks. And then, you know, going later in the afternoon, we'll have in parallel with some other sessions, some other Pluto presentations. And the team is just really working hard towards that particular set of presentations. I wish I could be at DPS this year. I'm sure Emily will be in the room and we will get a full report from her. And I

hope that this won't be the last time we talk to you either. Before I let you go, how's the spacecraft doing? Well, that's been the other wonderful thing. I mean, the spacecraft just survived the Pluto encounter. If you recall, we were worried that there may be some dust in the system

that would impact the spacecraft and potentially cause some trouble. But as far as we can tell, everything has just been working beautifully. And in fact, you know, we talked earlier about how long it takes to get all the data down. But in fact, it would have taken even three months longer because our original plan was to send back all of the data lossy compressed first, the JPEG artifacts, but just to make sure that we got everything down. But everything was working so well after the encounter, we said, you know what, the risk that something is going to go wrong now that we've passed Pluto and the need to send back

the data down to lossy compressed, let's just forget about that. Let's just go straight to the systematic downlink of the losslessly compressed data and the full image quality, the full quality of the data. Let's just start that. And so we chopped out three months that we would have had originally set aside for the lossy compressed data downlink. And we just went straight to the losslessly compressed. And that will get us settled with all the data on the ground three months earlier, which is great. But that was testimony to how well all of our spacecrafts is working the spacecraft subsystem. You know, there's been no deterioration at all in the spacecraft. I have one other question that Emily wanted me to ask you. Of course, you know that she and our boss at the Planetary Society, Bill Nye, were thrilled to join you for the encounter back there at APL.

Since then, has the science team sort of dispersed? I mean, how do you work now? How do you keep the open exchange of data and ideas flowing on this big team? We've divided up the science objectives into four different themes, science themes. We have science-themed teams. One is GGI, geology and geophysics. Another is composition. Another is atmospheres.

Another is plasma and particles. And each of those teams has been holding web cons, basically. Every week, each team meets. In fact, we have one for GGI today because we're keeping our noses to the grindstones and, you know, systematically going through and analyzing the data and then talking about it as we get into the analysis. And that's been partly also to so that we could have some great new results every week for the public. The outputs from each of those science theme teams has been the raw material for these public releases that we have every week. So the teams, not only are we exchanging emails, we have list serves for each of these science theme teams.

So we communicate that way as people make their way through the data. They report to each of the teams via these listservs. But then we have regular, regularly scheduled weekly webcons where we go over the data, you know, maybe a different person each week who discusses, wow, this is what I found and, you know, gets feedback from the rest of the team. So that's what we've been doing, and we've also, in addition, been working on actually trying to synthesize various ideas, write them down, getting ready for the Division of Planetary Sciences meeting in November. That is going to be one exciting meeting. How long before the next encounter?

New Horizons is not done examining the Kuiper Belt? Oh, that's right. You know, we're starting up the planning. In fact, we're about ready to do a trajectory course maneuver. We're going to fire the hydrazine thrusters on the spacecraft October the 22nd, you know, next week for the first time, and we have a series of four thruster firings that'll take place to put us on a trajectory to 2014 MU69. A Kuiper belt object that was discovered with Hubble last summer will divert the trajectories to enable a flyby of that Kuiper belt object, a very different kind of Kuiper belt object, which we call a cold classical, as opposed to what we had in the Pluto system, which are Plutinos. Those are resonant Kuiper belt objects. They're in resonant orbits with Neptune. This

other Kuiper belt object that we hope to fly by, we're going to put in a proposal to NASA next spring with some details about what we plan to do, the scientific objectives of flyby. But we already know that the spacecraft, after these maneuvers that will be taking place over the next several weeks, finally finishing up the first week of November, after we finish those maneuvers, will pass by this Kuiper Belt object, this cold classical Kuiper Belt object,

on January the 1st, 2019. So set your calendar, set that up in your calendar to, you know, and a few months before that is when we'll first acquire it with the LORRI instrument on New Horizons, and then we'll have a flyby. Can't wait to do it all again. Hal, thank you so much for sharing all of this wonderful science and your enthusiasm for this mission and what it has revealed about Pluto and its little family out there. Someday, maybe in 200 years, I think this system is going to be a very popular tourist spot. Yes. Again, thank you so much, and best of luck as this mission continues.

Well, thank you for everything that you do. And, Emily, you're great proponents for the NASA's planetary program, and you do a lot of great work, and thank you for everything that you do. And Emily, you're great proponents for NASA's Planetary Program, and you do a lot of great work. And thank you very much. You are most welcome. Research Professor Hal Weaver is the project scientist on the New Horizons mission. He has been doing great planetary science since 1978, spending the last 13 years at the Johns Hopkins University Applied Physics Laboratory in Maryland, that's headquarters for the New Horizons mission, his work blankets this and other solar systems, including groundbreaking discoveries about comets.

His detection of water in Comet Halley earned him NASA's Medal for Exceptional Scientific Achievement back in 1988. We'll be right back with this week's look at the night sky. That's what's up with Bruce Betts in just a few seconds. Time for what's up on Planetary Radio. Therefore, we are joined by Bruce Betts, the Director of Science and Technology for the Planetary Society. Yet another guy who will join Bill Nye and Neil Tyson and me on stage at the 35th anniversary celebration. More to explore. Yes, we know some of you have already passed the date.

Still, we're excited. It's still a few days away as we speak. Welcome. Thank you. I don't know what you're going to be doing. I want to be surprised. It's going to be a variety show, I hear. Not just you, the whole thing.

I'm not going to give it away. Just a hint, you might want to wear a poncho. Okay. I was thinking of other protective gear, nfl protective gear because i thought you might juggle on stage but okay oh i never drop anything no you just throw things oh that's true all right what's up pre-dawn sky is super awesome mars venus and jupiter and they are close together venus is the brightest then jup, and then Mars is much dimmer and reddish. And Jupiter is above Mars by just a little bit and getting closer to Venus, which is above

that. And Venus and Jupiter, the two brightest planets, two brightest objects up there besides the moon and the sun, will be almost just a degree apart on the 25th and 26th of October. So worth seeing that planetary conjunction. Excellent. Things have picked up in the sky. They're a party. On to this week in space history. The amazing Mars Odyssey spacecraft went into orbit 14 years ago, still working. 14 years ago, still working. That is some hardware. It is incredible. In 1967, Mariner 5 flew past Venus.

Interestingly, it was originally designed to go to Mars, but when Mariner 4 worked at Mars, they made some modifications and sent it to Venus. It didn't just turn around in space and go the other way. You know, that's harder than you might think. So I've heard. Pesky orbital mechanics. Forgot the keys to the Mars hab.

Okay, I'm done. Alright, on to random space fact. Very sexy. So, continuing our planetary society, 35th anniversary celebration. As of 1980, there had been a total of 79 human space flights. As of 2015, 310. Wow.

Very impressive. Oh, by the way, on our Halloween show next week, our Halloween visit to Mars with Andy Weir of The Martian, we're going to have a great Random Space Fact intro. So stay tuned. Because it's not mine. No, no, it's just especially good. Yours are lovely.

No, I know. It is especially good. You are correct. Yeah, you've heard it. All right, on to the trivia contest. We asked you, as of 1980 and 2015 each, how many planets had been orbited by spacecraft? How did we do, Matt? Made people work for this.

Because of that, I think our numbers were down a little bit. So those of you who got in, random.org says your chances were better. Our winner, if he got this right, is Steve Wienel, a first-time winner in Antelope, California. Regular listener, I think. He says as of 1983 had been orbited, as of 2015, that number is six. Is he correct? That is indeed correct. We had Earth, Mars, and Venus in 1980, but we have added Jupiter, Saturn, and the other direction, Mercury. So, Steve, congrats. You have won. You're getting a Planetary Radio t-shirt. And these are cool. Talk about things that Bruce throws. Planetary Society rubber asteroid of your very own. Yeah, everybody throws those. You can't help yourself. Like a lot of people who responded, he said, six in 2015, seven if you include dwarf planet Ceres.

He adds as justification, dwarf human is a human, therefore dwarf planet is a planet. Tell it to the IAU. Yeah, these terminology fights, they're hard. I don't like to get into them. But Ceres is a fine and interesting body. Absolutely, as we are hearing more of almost every day. Uranus and Neptune, of course, the folks who were left out. We got this from Torsten Zimmer, a quote from Uranus, an interview that he read a few years back.

I guess I'll never get a second chance to make a first impression. I was a little bit dull that day during the flyby of Voyager, and I think my name might have played a role as well. Maybe a name change and using the planet dating site eplanet.com. I like that. Planetharmony.com. I don't know. Planetharmony. Planetmatch.

You're on. We're going to get rich. Yeah. Oh, don't use this in the show. Okay. I'll leave it out. Surprise. Oh, don't use this in the show. Okay. I'll leave it out. No problem. You know how wealthy those planets are.

Jacob Pribnow, finally, of Lincoln, Nebraska, with a sentiment we can all get behind. He says, I'm on the Zibby Turtle train, our guest a few weeks ago. Let's go to Uranus and Neptune. We're ready for next time. We continue on. and Neptune. We're ready for next time. We continue on. As of 1980 and 2015 each, how many asteroids had been explored by spacecraft via flyby or orbiter? And Matt says I may be getting too hard. So here's a hint. In 1980, the answer is zero. Gosh, you're halfway there. So figure it out as of 2015. Go to planetary.org slash radio contest and get us your entry.

You have until Tuesday, October 27 to get us this answer. That would be the deadline of 8 a.m. Pacific time and the prize. We're going back to this. We did this a few years ago, but it's been a long time. You've got a Planetary Radio t-shirt, but how about

the science guy, Bill Nye's voice on your answering system will send you an MP3 with a personalized greeting to all of your buds. There you go. Cool. Go out there, everybody. Look out in the night sky and think about improvised maracas. Thank you and good night. I hope this doesn't have anything to do with why I need to wear a poncho at the anniversary celebration. You never know. He's Bruce Betts. He's the Director of Science and Technology for the Planetary Society,

who joins us each week here for What's Up. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its cosmic members. Danielle Gunn is our associate producer. Josh Doyle created the theme music. I'm Matt Kaplan. Clear skies.