Planetary Radio: Space Exploration, Astronomy and Science - Mysterious Tabby’s Star, With Tabby Herself

Episode Date: January 10, 2018

It may not host an alien “megastructure” but Tabby’s Star still guards many mysteries of science. Astronomer and astrophysicist Tabetha “Tabby” Boyajian leads the worldwide team that is revealing this strange light in the sky.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Tabby Starr, with Tabby herself, 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. Astronomer and astrophysicist Tabitha Boyajian is here to talk about the star that has generated so much speculation in the last couple of years. She'll tell us that the evidence for alien megastructures has not shown up, but the science she is uncovering is still extraordinary. Bruce Betts and I have not one, but two new contests to tell you about in this week's What's Up, even as we prepare for the next total eclipse. you about in this week's What's Up, even as we prepare for the next total eclipse.

First, though, we journey back to Mars with our favorite tour guide, Planetary Society Senior Editor, Emily Lakdawalla. Emily, another great and comprehensive update on Curiosity as it slowly crawls toward the release of your new book as well, which I don't like to miss a chance to plug that that's coming up in March. But let's talk about the latest from the rover, including its progress on the red planet. Yeah, so it's been almost four months since my last update. I was having trouble finding a good stopping point, but curiosity got to a really interesting place. So in the last four months, the rover has been crawling sort of southish, perpendicular to Vera Rubin Ridge,

which used to be known as Hematite Ridge, because from orbit, the CRISM instrument on Mars Reconnaissance Orbiter saw signatures of the mineral hematite, which is an iron oxide that generally forms in liquid water. So they've been eager to get to this ridge for a long time. The ridge does have very pretty looking rocks. The lower part of it had these very finely laminated, very thin layered rocks that were actually pretty similar to the ones that Curiosity had been driving on until that point. these windows of more bluish grayish rock peeking up through the reddish layers. And those contain all kinds of interesting looking features. So it's been pretty fun to follow the scientists crawling around looking for hematite spots and seeing what they see in these bluish rocks. What's going on with these color images taken from orbit? The images from orbit are from not a camera exactly,

although it is sort of a camera, but it's a camera that can see in way more than three different wavelengths. It's a hyperspectral imager. And so they're able to actually get a spectrum at every spot. And the spectra have little dips or wiggles in them. And those wiggles happen when light interacts with the molecules or the crystals of certain minerals in certain ways. So wherever there's a wiggle, that can tell you that there's a certain mineral present. And so in this case, they're looking at maps of where there is a strong dip because of a particular absorption that happens with hematite. And I think one of the coolest things about this story is that the person who put together those maps, or one of the people, is none other than Abigail Freeman,

who used to be one of the Planetary Society's student astronauts on the Mars Exploration Rover mission. She was one of my students back then, and I'm just so proud of her. So that's one of my favorite details. We are all very proud of her. And you can see the results of this color imagery, the spectroscopic imagery from space with one of Emily's patented little slider images. And before we move on, I've got to mention one of those finely laminated rocks. It's just such a pretty picture of this rock called Widom. It is really gorgeous. And, of course, we get these gorgeous images because of an amazing camera on the end of the robotic arm called MOLLE, the Mars Hand Lens Imager. Most people hear about MOLLE when it takes self-portraits of the rover, but it wasn't just sent up there to take selfies.

It was sent up there to take super close-up images of rocks and see these amazingly fine features. We can't possibly cover everything that is in this latest piece, but I do encourage you to take a look at it. It's a January 6th update at planetary.org, Emily's blog, of course, the Planetary Society blog. Just a couple more things that I really would love to talk about, even without its drill, Curiosity going back to doing wet chemistry, but on purpose. Oh, yes. So it's SAM instrument.

It's the little oven inside the belly of Curiosity that can heat up drilled materials and sniff the gases out of the oven and use that to tell the composition of the rocks and whether there's organic molecules present or isotopes or other cool things. It took along with it a small number of these wet chemistry cups that contain a solvent that can make organic molecules easier to detect. And it finally used one of those for the first time. And I don't have any specific results to report from that, but I can tell you that the scientists are very excited about what they saw. Yeah. In fact, you said that Ashwin Vasaveda, because he's a good scientist, he wouldn't tell you what was up, but there is something interesting going on.

Definitely. And we should hopefully hear about it in March at the Lunar and Planetary Science Conference. And I said, first, wet chemistry on purpose for good reason. I guess there was a little bit of a spill once. Yeah. One of the cups evidently leaked on the way to Mars somewhere. And so the SAM team has been dealing with this derivatization agent, this solvent being kind of loose around the inside of SAM for a long time. It's kind of made some of their results difficult to interpret, but they've

really gotten a handle on the problem. And so they were ready to try to actually on purpose pierce one of these cups. And you have told us that that long time bulky drill, they may be close to getting that workaround to get going. Yeah, hopefully so. So these exciting rocks, I think before Curiosity drives down off the ridge, they should have a chance to drill into some of them. Let's cross our fingers. All right, just one more topic. And that is, well, you've included an image of this rock, which has been getting some perhaps undeserved attention because of some little figures on it, which you call sticks. Yeah, I think the mission is referring to them as sticks too. They're these funny things poking out of the rock. They're a different color. To my geologist's eye, they look like places where there were large crystals that formed inside the rock, maybe when it was very wet with mineral rich water. And either we're looking at

the actual crystals that formed, or we're looking at places where those crystals dissolved away, and then were refilled again with another mineral. It happens a lot in earth rocks. And so I think that's what we're seeing here. But of course, the conspiracy theorists on the internet got a hold of this. And actually, it's not totally fair. There are some geologists on the internet who are like, wow, those look like trees fossils. And yeah, it's within the realm of possibility that these could be fossil evidence of life on Mars. But we have got to go back to Carl Sagan and say extraordinary claims require extraordinary evidence. Just a photo is not going to convince me of that.

Thank you, Carl. It's all waiting for you. This and much more along with these great images in that January 6th blog entry at Planetary.org. And what, a couple of months to go till the book? Yep, should be out in early March. Thank you, Emily. Thank you, Matt. Senior Editor for the Planetary Society, that's Emily Lakdawalla. Freeman Dyson speculated way back in 1960 about how a super-advanced alien civilization

might capture all the available energy of a star. The great physicist had no idea these spherical megastructures, hundreds of millions of kilometers across, would one day be given his name. Fifty-five years later, a star would be named after the astronomer and astrophysicist leading a team that has discovered some very odd things. Those findings would lead some to speculate that Tabby's star might host a Dyson sphere, or perhaps a partial one. Tabitha Tabby Boyajian continues to coordinate humanity's investigation of that star.

continues to coordinate humanity's investigation of that star. What she and her team are learning may not leave room for E.T., but it is remarkable science. Tabby spoke with me from her office at Louisiana State University a few days ago. Tabby, welcome, and thank you so much for being part of Planetary Radio this week, and congratulations on the publication of this paper that's going to tell us more about your star, Tabby's star. Thank you. And thank you for having me. I want to start with your TED presentation.

And we will put up a link to this TED Talk along with other relevant bits and pieces having to do with this work that you have underway. But you open that TED Talk with a quote that is a favorite, of course, of many of us at the Planetary Society. Extraordinary claims require extraordinary proof. Of course, it's a quote from our co-founder, Carl Sagan. Certainly applies in this case, doesn't it? That's the point the whole story was trying to get across. It's not good science. Wishes don't make for good science. But there is a piece of me, and I bet a lot of people listening to this, who wish that you had found something more mysterious, or at least indications that, you know, all that speculation out there about what might have been

circling the star and causing these strange dips in brightness, that maybe it might have been circling the star and causing these strange dips in brightness, that maybe it might have had something artificial behind it. Do you wish that the data had taken you more in that direction? I don't really feel that way in a sense. I'm just working through all these problems. You know, we're just kind of like chipping away at the block and we're able to rule out different hypotheses, the more data that we get and the different kind of data that we get. And this is kind of, you know, what we're working

with here. We're kind of set with a really big question and, you know, ask, you know, how do we answer this question? And this is the kind of steps that, you know, we work through to get to where we are today. It's called good science. Tell us about this star KIC 8462852. So KIC 8462852 is a star that was observed by the Kepler space mission, which was a NASA mission launched to find planets orbiting around other stars. And it did this by observing a large number of stars, over 150,000 stars, continuously for four years, measuring the brightness of each one of those stars really, really precisely. It was trying to detect the sign of a planet crossing in front of one of those stars and blocking out a tiny bit of light. We have talked a great deal about this mission, including the man who

worked so hard to get it into space and against great odds. Do you feel that it has been as important a mission as we've heard from so many other astronomers? Oh, yeah, absolutely. I think, you know, it definitely reached its mission goals. It revived stellar astrophysics, for instance, and the kind of phenomena that we can observe with this high precision photometry that, you know, wasn't necessarily related to exoplanet science, what the mission was designed to do, but it just kind of revealed so much more interesting phenomenon that we can study in so much greater detail and learn more about, you know, the physics of how our universe works.

Talk about what happened in 2015 that led to the publication of the paper that sort of opened up all the excitement about what is now very colloquially commonly known as Tabby's Star. That paper that you led the writing of called Where's the Flux or WTF? Yeah, so this star, as I mentioned before, it was identified from the Kepler data set. And I suppose we'll talk more about this later, but it was identified through the Planet Hunters platform, which is a citizen science online tool where users can sign on and look for interesting signals in the data,

nominally exoplanet transits. The thing is, you're looking through every star's data, and they came across this star, which really didn't fit into any bucket of things that stars do. Once the science team was notified, we started to try and learn a whole lot more about the star, try and figure out what was going on. This was several years prior to 2015 when the paper was published. It took quite a while to work through the many things that we could come up with until we got to the point where we had exhausted really all explanations that we could think of.

We kind of had to write it up and put it out there so the whole world can, you know, take a stab at trying to figure out what was going on. And a lot of people did get pretty excited about what you put out there. And there were not just a few, but many, shall we call them artist concepts of kind of fanciful stuff that might explain what you discovered at this star. I mean, what was so odd about the light curve? The light curve itself was, Kepler observed it for four years. So you have four years of ultra precise photometry. So how bright the star is. And most of the time the star is flat, meaning nothing is really going on. But then it's

punctuated in about a dozen different places with these dips. And these dips range from just less than a percent to over 20%. They're really not like any dips that we've ever seen because their shapes, their durations, when they occur that you can never really predict when the next one will come or what it will look like. Nothing really looked the same. We now know, of course, that planets transiting many, many stars cause these dips in brightness that Kepler has used to discover so many planets in our galaxy. But this one really did stand alone, right? Right. So a planet going around a star, you can think of it as orbit.

It will periodically cross in front of the star and block out the same amount of light every time it goes in front of the star. And it'll do this in a regular pattern each time that it orbits. This is not what we observe for this star. We observe very irregular dips in its brightness. These dips are all very different from each other. Some of them are very, very large. So we're talking about a planet will make maybe a 1% drop in a star's brightness. These drops, you know, go up to 20%. Were you surprised to see that the reaction to these findings went in the direction that they did that the speculation, you know, took off so, so wildly?

I think everybody was surprised that it pretty much went viral at that point. We really weren't prepared for that at all. You got to admit at least some of the imagination that went into some of the artwork that showed such things as Dyson spheres. Freeman Dyson has actually been heard on this program talking about what a Dyson sphere is, or at least Dyson spheres that were not complete, right? Because if somebody had actually built an entire sphere around this star, we wouldn't be seeing these dips and rises in the brightness of the star, right? Yeah, that's correct. We're really unsure, I think, how these things, you know, would look if they do exist. And so this is kind of, you know, where the artistic conceptions come from.

So we're back to extraordinary claims require extraordinary proof. Did you and your team set out after all this speculation started to try and examine this star more closely and eliminate some of these wilder possibilities? At that point, when this news came out, this was just identified as an interesting target for SETI searches, SETI being the search for extraterrestrial intelligence by my colleague Jason Wright at Penn State University. We had discussed a few months before the paper came out, a project to look for radio signals around the star using SETI, the Green Bank Observatory. We wrote a proposal to do that. And, you know, at this point, you know, things were still in the works. We're still,

you know, working on the paper. It hadn't come out yet. We submitted the proposal. It was this proposal, the idea of this proposal that got leaked to the press. And that's kind of what started the whole hysteria around, oh, wait a minute, scientists can't figure this out. So maybe it's the aliens. Yeah. Well, I know that that SETI search did take place. The Breakthrough Listen people were involved as well out of Green Bank, right? Was anything found? The observing run for that at Green Bank Observatory started in, I think, late October of 2017. I know it was fairly recent, right? Yeah, it was fairly recent. The data actually just got finished transferring to Penn State, where it's being hosted, I think, at the end of the summer of 2017. And so it's a huge amount of data, and it's going to take a lot of work to go through it and really do the search properly.

Is it safe to say, though, that in any preliminary consideration, if it's fair even to talk about preliminary data, that there doesn't seem to be much in the way of any mystery about radio emissions from the star or its vicinity? Yeah, I mean, it's a possible outcome, but it's not very probable. And we knew that from the very beginning. Yeah. In the meantime, your examination of the star with the help of all of these citizen scientists around the world, it continued to the point where now you've got this paper that is about ready. It has been accepted by the Astrophysical Journal Letters, and we can put up a link to a draft of it, a January 3rd, 2018 draft. This paper has to be a little disappointing to people out there who really wanted to find the work of E.T. at Tabby's Star. I can't speak for them. I don't know.

No, I certainly do not expect you to be their spokesperson, but you have said that the indications are that it probably has a much more, what's the word I want, prosaic explanation? Yeah, a more ordinary explanation. The main results of the paper are, one, we actually saw it doing its thing again. We never really knew if it would do its thing again at all. That was a huge accomplishment that's detailed in the paper. And we also got some really special data that we didn't get when the Kepler Space Telescope observed it, is that we observed it in many different colors. So light comes in, you know, kind of a spectrum of colors. We observed it in, say, blue and yellow and red. And we're able to measure how deep these dips were in each one of these colors. We observed it in, say, blue and yellow and red. And we're able to measure how deep these

dips were in each one of these colors. And this is important because this will actually tell us the kind of material that's passing in front of the star, if that's what it is. Imagine if you had a planet that's going in front of a star or something very opaque, like a megastructure or Dyson sphere of some sort, you would have it block all colors of light equally. And what we saw in our data was, in fact, that the blue light got blocked more than the red light. This kind of signature points to whatever is doing the blocking being dust. I wouldn't be surprised if there aren't a few folks out there who are saying, oh, yeah, well, the aliens just built big color filters into their Dyson sphere to make it prettier.

There's plenty of that out there, yes. This dust and the fact that you are, as you said, because color can tell us so much about what's happening elsewhere in the universe, is there a chance that we will learn about the composition of this dust? universe. Is there a chance that we will learn about the composition of this dust? With the data we have, you know, in this paper, we're able to constrain kind of the particle sizes down to, you know, much less than, you know, a couple of tenths of a micron or so. Wow. There's still a lot to be learned. We see this signature that indicates dust and these dust particles are likely pretty small. small, which seems to indicate that

this dust is probably circumstellar, so it's going around the star in some way. That being said, we don't know what created the dust, where it's coming from, where it's going, the processes that are involved in explaining these variations, as well as the very long-term variations that we haven't brought up yet. This star is known not just to have these short-term, very wacky-looking dips, as Kepler observed, but also go through variability in very long-scale times. So we're talking about years to decades to even possibly centuries. This is amazing. And also that just that you can determine the probable size of these dust particles that are circling a star that is almost 1300 light

years away from us. It's quite incredible what we can do with the instrumentation available today. I agree. Astronomer and astrophysicist Tabitha Tabby Boyajian. She has more to tell us about her star and how citizen scientists are helping us reveal its secrets. This is Planetary Radio. Hi, this is Casey Dreyer, the Director of Space Policy here at the Planetary Society. And I wanted to let you know that right now now Congress is debating the future of NASA's budget.

The House has proposed to increase NASA's budget and also increase planetary science in 2018. The Senate, however, has proposed to cut both. You can make your voice heard right now. We've made it easy to learn more if you go to planetary.org slash petition2017. Thank you. You can share your passion for space exploration by giving someone a gift membership to the Planetary Society, this holiday season or any time of year. Your friend or loved one would join us as we nurture new and exciting science,

advocate for space, and educate the world. The gift of space starts at planetary.org forward slash give space. That's planetary.org forward slash give space. Because come on, it's space. Welcome back to Planetary Radio. I'm Matt Kaplan, ready to continue my conversation with astronomer and astrophysicist Tabitha Boyajian. Tabitha has led one of the most detailed examinations of an individual star in the history of astronomy. That star earned the attention it's getting by exhibiting the strangest fluctuations in its brightness of any star found so far. An alien megastructure like a Dyson sphere is probably not responsible, but there's still much more for us to learn about Tabby's star. With much more to learn, therefore, about this star, I wonder, do you stand by a description that you gave it some time ago as the weirdest star we've found so far?

Well, I guess I'm biased, perhaps. Well, it is your star. But, you know, to have this much effort and work and go into studying just a single object and we're still kind of scrambling to, you know, really come up with a physical model to explain it. Now, you know, we have data that points to dust, but, you know, just painting that picture of, okay, well, now what? We're still really

trying to work that out. It is still a big mystery. It's just, you know, we have to work at it in many other different ways. And the good thing is that, you know, we have boatloads of data now from this whole summer, the star started doing really funky things, and we continued to collect more and more and more data. And hopefully in another 10 years or so, we'll have even that much more data that we'll be able to really be able to test out certain theories involving, you know, what's going on with the star. Having this much data about an individual star, does this represent sort of a revolution, maybe too strong a word, but an important evolution in astrophysics and our study of the other stars, the hundreds of billions of them just in our galaxy? Yeah, I think it does represent a new era in the amount and quantity of data that we can collect with the available instruments out there,

very, very widespread. But most importantly, I think, is this whole field of time domain astronomy, which is, it's kind of a new deal. This project here was made possible with the Los Cumbres Observatory, which is a telescope network that's completely robotic, and they have stations situated all over the globe. The scheduler goes and tells the telescope to make your observations, say, every two hours, and then it goes off and points at other things, comes back, observes your star, continues doing that throughout the night until the sun comes up at a certain location, and then it passes this schedule on to the next station where it is dark out. And so you have a continuous eye on the sky, no matter where you are in the globe.

And telescope time still, for the most part, costs money. And you were able to raise some from the public. Yeah, that's right. We had a very successful Kickstarter campaign where we decided to pass this theme on of, you know, the star was discovered by the public and perhaps the public would still want to help us learn more about the star. And so we were able to raise over $100,000 to purchase observing time on this network of telescopes to monitor their star and figure out what was going on. This paper that will appear shortly, as we said in the Astrophysical Journal letters, it's titled, by the way, the first post-Kepler brightness dips of KIC 8462852. You've got a lot

of co-authors, co-investigators on this paper. They include people whose names will be familiar to listeners to this show, Alex Filippenko, Amy Meinzer, many others. How did so many people get involved with this? That's a really good question. Well, we're monitoring. We had a kind of smallish network of folks that were collaborating on triggered observation. So when we saw the star start to dip again, whenever that would be, we would notify our smaller network and say, okay, well, you know, let's get some spectra or let's get some, you know, high resolution images. And so that network was notified at this point. And we decided to, you know, use what everyone else uses today is Twitter to kind of get the word out a little broader. And we had an amazing response from

the whole astronomical community. I would say the whole astronomical community, but pretty much everyone at a telescope that night pointed their telescope and got some observations for us. And so it was very much a collective effort of both amateurs and professionals to get all this data so we could figure out what was going on. And these are just the people who had access to the telescopes, professionals and amateurs, as you said. Let's talk now about the Planet Hunters Project and the vital role that it played in this. I'm going to guess to begin with that it has made you a big believer in citizen science. Oh, yeah, absolutely. I personally, I never heard of citizen science before I got to Yale, where I started working with the Planet Hunters group.

And it's just, it's impressive any way you look at it. It really is. Any way you look at it, it really is. And this Planet Hunters, I think it was founded, among others, by Deborah Fisher, somebody who's an old friend of this program, who you spent, what, four or more years working with at Yale? Yeah, that's right. So how were you able to use these citizen scientists around the world as part of the Planet Hunters Project to help you study Tabby's star? The Planet Hunters Project, like you said, was founded by Deborah Fisher in hopes to find planets in the Kepler data that the computer algorithms would have missed for whatever reason, right? And so it was a huge gamble on whether or not, one, people would actually be interested in looking at time series data,

which it really isn't that interesting if you compare it to something like Galaxy Zoo, where you're looking at pictures of galaxies. It's in a completely different class. But also that, you know, how would a computer actually miss something that is by nature periodic? But actually, the project, you know, when I got there was extremely successful. And the few years that I was there, we found, you know, numerous other planets that had been undetected by the computer algorithms. Another strength of Planet Hunters is that it actually works so that you can have serendipitous discoveries just fall into your lap without even doing much work in the sense that the computer program, you actually have to tell

the computer exactly what to look for and it will find that for you. It won't find anything that you don't tell it to look for by nature. But planet hunters, you have just humans sorting through data and looking at it. And this is a very easy way to identify kind of oddities. And this is how this star, KIC 8462852, is found. It is, in some ways at least, an almost unprecedented team of professionals, amateur astronomers, and citizen scientists who learned on the Planet Hunters site, which is planethunters.org, and they are still recruiting people. You can still go there and go through the tutorials and join this effort to find new worlds around our galaxy.

It's quite something, I think, to have led a team like this. I'm also thinking of your own team, just as you were once a postgrad at Yale with Deborah Fisher. You've got your own folks now at Louisiana State University, even including undergrads. What're all here to help, you know, in teamwork, trying to solve things, finding the optimal way to work through something. It's really amazing to have these young researchers here and be able to train them to do science. And this is an amazing opportunity for them, I think, to, you know, get involved with it. I don't want to close before we talk a little bit more about astronomy that can be done from space. And I wonder if there are any upcoming efforts that you are excited about that will, you know, follow on the legacy of the Kepler mission. I'm thinking in particular of TESS, this Transiting Exoplanet Survey Satellite that is, I believe, supposed to launch this year. to launch this year. Yeah, TESS will be super exciting, I think, but it's an entirely different parameter space than what Kepler gave us. Kepler did kind of like a point and stare. So it picked this one tiny, tiny spot in the sky, stared there for four years, and then that was it.

Then it moved on to its K2 mission, which looks at each spot in the sky for 90 days or so. The TESS mission is doing more of an all-sky survey. So it's looking at the entire sky, most of it only for about a month. But once you get up to the poles, you're looking at about 300 days or so. And so it's kind of a new parameter space that we're looking at, but we're looking at the entire sky, which is pretty amazing. And so we'll have a lot more data to work with. We're actually working with the idea of putting test data into the current Planet Hunters program.

There's still tons of planets, I'm absolutely sure of it, left in the Kepler data set. It's not that, you know, we're done with it. You know, it's found everything that we could have found, like there's still a lot of really good stuff in there. Having test data fed into Planet Hunters as well. And so maybe, you know, users could choose which to pick, you know, one over the other is definitely something that we're working on, I think will be really exciting in the next year to come. Are you looking forward to a new generation of even more powerful instruments, both on the ground with the appearance of these giant new telescopes, like the giant Magellan telescope, but also more powerful instruments

in space, James Webb Space Telescope, and down the line, the WFIRST? Yeah, I think all these new opportunities will, you know, let us explore space in new ways that we have not been able to sample before. And just it kind of humbles us to when we point out in space and we think that we know everything and then we find all sorts of crazy new objects that we never knew about. These are the instruments that really kind of push the limits. They go way beyond the limits of what we could have learned with the current data in hand. And this is when we actually make really awesome discoveries. And those surprises, they're half the fun, aren't they? Yeah, that's why we do what we do.

Tabby, thank you again for joining us on Planetary Radio. And I look forward to hearing more about Tabby's star as you sift through that other data that continues to arrive, but also about all the other surprises that await us around the universe. Well, thanks so much. You know, we have several other papers in line coming out, you know, in the next couple of months or so dealing with this data. And then hopefully in the years to come, we'll kind of, you know, be able to settle on, you know, what's really happening. So I appreciate your interest. I hope you'll come back and talk about some of those some of that work when it gets published.

All right. We'll do. We've been talking with Tabitha, that's Tabby Boyajian, assistant professor of physics and astronomy at Louisiana State University. physics and astronomy at Louisiana State University, and in particular about that star known as KIC 8462852. That's its official nomenclature, but it is much more popularly known as Tabby's star in her honor. Bruce Betts is back for the second installment of Planetary Radio in the new year. He is the Director of Science and Technology for the Planetary Society. Welcome back. Hey, Matt. How are you doing this week?

I'm doing much better, thank goodness. This flu slash cold does hang on. I've just got a touch of it, but boy, do I feel better than I did last week. Good. Yeah, I hope you're better than I did last week. Good. Yeah, I hope you're holding up okay. Doing great. Good. Tell us about the night sky. It's the pre-dawn where things are happening, and it's just planetary craziness going on.

Super bright Jupiter in the pre-dawn east and up a couple hours before dawn. Above it is Mars looking reddish. To their lower left, you will find Mercury for a few more days and Saturn coming up for the long haul. And on the 12th and 13th of January, Mercury and Saturn will be switching places and be hanging out close to each other. Saturn will be switching places and be hanging out close to each other. Saturn is a little more yellowish, Mercury whiter and a little brighter. So it's a planetary party. I heard something about a lunar eclipse coming up later this month. Do you know about that?

Oh, totally. There's a total, total lunar eclipse later in the month, January 31st. It will be visible from the Americas and from Western Europe. I'll get you more details or you can look them up online. It's going to be good. We can definitely talk more about it next week as well. But if you're picking this up and it's January 30th, go online and get more information because it's the 31st, you see. January 30th, go online and get more information because it's the 31st, you see. Should plan further ahead for such wonderful and glorious things as a total lunar eclipse.

We move on to this week in space history. It was this week in 2005 that the European Space Agency Huygens probe landed on Titan. Come on. More than 12 years ago. Wow. 12 years ago. No! 12 years ago. No, no, it's 2018. Ha! 13 years ago.

All right, let's go on before I get depressed. Sorry, but still speaking of the Huygens probe... That was the sound of it going through the atmosphere and hitting it. That was remarkably accurate. I know. The Huygens probe took nearly two and a half hours to descend through the atmosphere of Saturn's moon Titan. It parachuted down and the combination of things like the low gravity and the very, very thick high atmosphere because of the low gravity contributed to the length of the

descent. Wow. atmosphere because of the low gravity contributed to the length of the descent. Wow. And there is that really wonderful audio file tracking Huygens as it descends to the surface. It's eerie and a lot of fun to listen to. We also worked with the members of the science team and converted their acoustic data into an audio file. but since you're going through the wind, it might be time for me to redo the two and a half hours in 10 seconds, my approximation of the actual audio file. I think this would be perfect timing. All right, here we go.

Thank you. Thank you and good night. You can hear the landing very distinctly, but other than that, it's a lot of wind noise. We move on to the trivia contest. I asked you, what was the last successful Soviet mission to the moon? How'd we do, Matt? I know fooling around. Here is a first-time winner who has nice things to say about the radio show,

but really it's just Random.org's doing. Stephanie Delgado. Congratulations, Stephanie, in Tucson, Arizona. She says Luna 24 was the last successful mission by the Soviets to the moon on August 9th, 1976, and that it was a sample return mission, a successful one at that. It was indeed.

Congratulations again, Stephanie. She says fantastic and engaging education and inspiration for 15 years. Here's to 15 more. Congratulations. Stephanie, congratulations all around. You are going to receive that space magnetic poetry kit for your refrigerator door. I hope you have a nice steel refrigerator door and a 200-point itelescope.net astronomy account from that worldwide non-profit network of telescopes that you can use anywhere in the world or donate it to your local astronomy club or a school or anybody you like. I got a few more. Eric Bruner, Cary, North Carolina. He says, unless Vladimir Putin has only been pretending that there is no more Soviet Union, Luna 24 will always be the last successful Soviet mission to the moon.

This from Ian Kennedy, reports of a manned sample return mission to the lunar surface by a small startup based in Lancashire, UK, allegedly in search of untapped reserves of dairy products, remain unconfirmed. Do we have any Wallace and Gromit fans out there? Cheese, Gromit. Cheese. Ian hails from Dundee in the UK.

And finally, this from our poet laureate, Dave Fairchild, in Shawnee, Kansas. Regolith is what they call the dust and crumbled rock, the glassy bead agglutinates that cover moon's bedrock. When Luna 24 returned, the Soviets' last fling, a total of six ounces is the payload it would bring. Thank you. Thank you, one and all.

We love to get your mail. We love to get your entries. And you're going to get a chance to do this again. In fact, we've got two contests to tell you about. But Bruce, tell them what you've got for next time. As measured by surface area, what is the largest known body of liquid on Saturn's moon Titan. So that would be liquid methane ethane. Go to planetary.org slash radio contest and get us your entry. You have until the 17th of January, January 17. That's a Wednesday at 8 a.m. Pacific time to get us this answer. And if you are chosen by random.org and have the correct answer, you will win yourself a Planetary Society T-shirt.

The very cool Venn diagram with the society in the middle with Mars and Earth making those two circles that intersect, along with a 200-point itelescope.net account. Now, that other contest, I told you about this, right? That the Aerospace Corporation is doing. Did you look it up? Are you going to enter? Oh, I probably should, shouldn't I? Yeah, why not? Why not?

It's free. Our friends at the Aerospace Corporation, in particular at their Center for Orbital and Reentry Debris Studies, which is at www.aerospace.org slash cords, C-O-R-D-S slash. You know, I know that's a lot to remember. If you go to our show page for this week at planetary.org slash radio, we'll put the link there as well. They decided to have a contest. You can put in your guess of the date and time that the Chinese space station, Tiangong-1, will re-enter and

either strike or not strike. Maybe it'll burn up entirely in the Earth's atmosphere. But the date and time that that will actually re-enter the Earth's atmosphere. And the winner is going to win some aerospace swag. But they are happy to have us share this with our listeners. Yeah, they've done some estimations of the approximate time frame that it'll enter. You remember the, of course, you remember the Skylab reentry in 1979. Similarly, uncontrolled, unclear where it was going to hit. My favorite part was that people had t-shirts with bullseyes on them just taunting it. That's right, yeah. And I think Taco Bell ran a competition that time.

They actually made a dish using Skylab parts later on. Oh, so much possible Taco Bell humor comes to mind based on that. But those are the two contests. With that, I think we're done. Everybody go out there, look up in the night sky and think about what it would be like to be on an island in the middle of a methane-ethane sea on Titan. There are islands there. It would be weird. Thank you and good night. I wonder how hard it would be to get an umbrella into that frozen surface hard pack water ice. A little tiny umbrella? Oh, a beach umbrella.

Right, a beach umbrella. Although, you know, a tropical cocktail with a little paper umbrella would be nice too. I don't think the umbrella would be really important on Titan. The sunlight's just not that bright through the haze. Yeah, and it would probably also be a mistake to open your helmet to drink a Mai Tai there. Probably. He's Bruce Betts. He's the Director of Science and Technology for the Planetary Society,

who joins us every week here until we can get that tropical vacation on Titan for What's Up. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its Star Bright 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.