Planetary Radio: Space Exploration, Astronomy and Science - Kepler Discovers Hundreds of Exoplanets

Episode Date: July 5, 2010

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Kepler discovers hundreds of new planets in our galaxy. That's this week on Planetary Radio. Welcome to Public Radio's travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. We may know soon if the Kepler Space Telescope has doubled the number of known exoplanets, worlds orbiting other stars. William Barucki is the mission science principal investigator. He'll join us once again, this time to describe this astounding discovery. We have lots more for you in today's busy show.

Bill Nye, the science and planetary guy, has found a surprising side effect of climate change where no one expected to see it. And Bruce Betts has helped me decide who should get our help buying a slightly used, slightly singed space shuttle, cheap. Bruce will also tell us about some great stuff to look for in the night sky. Let's get started by visiting with Emily Lakdawalla. Emily, how goes the vacation? It's been nice to get a break. I won't lie to you. I'm looking forward to it. Mine starts after preparing today's show. So tell us what's up for the month of July.

Well, I picked my vacation to be in between the excitement of Hayabusa and Icarus last month and the excitement of Rosetta, the European Space Agency's comet chaser, encountering asteroid Lutetia early this month. That happens on July 10th. It'll fly past Lutetia, which is asteroid number 21, and that low number tells you that it's one of the biggest asteroids in the belt, and it's certainly the biggest one that has ever been visited by a spacecraft before. So that's almost immediate.

Some people hearing this may actually have missed it, but can look it up on the blog. That's right. What else do you want to point out? Well, this year I think is interesting because there's a whole lot of stuff going on with missions visiting small bodies in the solar system. We're upon the fifth anniversary of Deep Impact's flyby of Tempel 1. That spacecraft just flew past Earth last week on its way to encounter with Comet Hartley 2 in November. Meanwhile, speaking of Temple 1, there's a spacecraft on its way to visit it, and that's Stardust, the one that flew through the

tail of a comet and returned bits of it to Earth, is going to be returning to Temple 1 in February of next year. You had a personal encounter on your vacation with Stardust. That's right. My vacation is in Washington, D.C., and I took my two little daughters to the National Air and Space Museum, and we took a look at the Stardust sample return capsule. I'm not sure if my 3-year-old really understood what I was talking about when I said that it had brought back little bits of a comet,

but it was kind of fun to stare up at the underside of the capsule and see the burned, blackened, crisped area where it had entered the atmosphere and came to rest on Earth. Pretty incredible. What else is in there? Because I know you've got a ton of stuff. Well, we'll definitely link to your look forward at July because there's much more there than we can talk about. Well, the other thing to take a note of is that this is the start of the extended, extended

mission for Cassini. It's already completed its primary and first mission extension, and so now we're on to its second mission extension, which will take it through 2017 and through Saturn's solstice. 2017 will be the end of the line for Cassini, though. They're going to plunge it into Saturn's atmosphere at the end. Yeah, and we, of course, will be having another conversation before too long with Linda Spilker, and anybody who isn't aware of it can look back into our archives

for the roughly three or four times a year that we check in with her about that mission. Anything else to add? I think I should just mention that IKROS is getting ready to start their attempts to steer the sail using only solar pressure. So far they've been working a lot with chemical propulsion, but they just returned some photos from the second deployable camera that shows that their little LCD patches, where they can brighten and darken sections of the sail, are working.

And so they're set to start trying to control the sail's motion with just light pressure. Emily, I think next time we talk, we still won't be catching you at home on Skype. At least that's not too likely. But we look forward to talking to you back on the job. Yeah, by then I should be back in the swing of things, energized and ready to follow what's going on in the solar system. Tanned, rested, and ready, as they say. Thanks so much, Emily. Thank you, Matt.

Emily Lakdawalla is the Science and Technology Coordinator for the Planetary Society and a contributing editor to Sky and Telescope magazine. She will join us next week with another look at the Planetary Society blog. Here's Bill. Hey, Bill Nye, the planetary guy here, vice president, but future executive director of the Planetary Society. And this week, global warming is making things cool. Wait a second. That's right. Global warming, climate change, is making the upper atmosphere cool off.

This is apparently because there's extra carbon dioxide, especially in the lower atmosphere, that's holding in more heat near the Earth's surface. So the heat that used to pass from the troposphere, the lower atmosphere, up to the upper atmosphere, isn't passing up there as quickly. The atmosphere is cooling off, the upper atmosphere is cooling off and getting thinner. Now what does this mean for you and me? Well, it means that space debris, old rocket boosters, pieces of spacecraft that used to burn up in the atmosphere aren't doing it because the atmosphere doesn't reach them anymore. So they're staying up there spinning around. So it could be in the not tootoo-distant future this stuff is going to start running into each other.

People have talked about this for a long time. The cascade where one piece of debris runs into another piece of debris and it shoots it up in all different directions and then very valuable satellites start running into the debris. And then while the solar cycle is making the sun's weather more hostile to our electronic communications, then we start knocking these satellites out of the sky at the same time. Oh, my friends, it's potentially crazy. But maybe the light sail technology that the Planetary Society is developing to deploy or unfurl our solar sails, maybe the same technology could be used to help bring debris down. This has

been discussed. It's another unintended and surprising consequence of human activity, making the atmosphere a little bit warmer, makes the upper atmosphere thinner, and human space junk isn't falling down the way we all thought it would. Oh my, if it isn't one thing, it's something else. I gotta fly. Bill Nye, the Planetary Guy. William Barucki has spent nearly 50 years helping us learn about our universe and make space a great place to work and do science. That's how long he has been working at NASA's Ames Research Center in Northern California, where he is a senior space scientist. But as we heard during his last visit

in January, Bill is also the science principal investigator for the Kepler mission, a very specialized space telescope that is spending years staring at one stretch of sky, watching for the almost, yet not quite imperceptible evidence of planets circling distant stars. Bill's team dropped a bombshell in mid-June when it announced evidence for hundreds of those worlds. Evidence picked up during a period of observation lasting just barely a month and a half. Bill, welcome back to Planetary Radio. And my goodness, congratulations on, well, effectively, we hope, doubling the number of known exoplanets. It's been a wonderful time. We've certainly found lots and lots of candidates.

We're hoping that many of these will turn into planets. But, of course, there is a difference between a candidate and a planet. We have a lot of work to do this summer with ground-based telescopes to confirm that the candidates really are planets. Until then, of course, we can't announce them, but we're very hopeful that we'll add a lot of planets to the known ones. When we talked to you last, in January,

you had announced the discovery of five, at least five fairly well-confirmed. All of a sudden, that's up, well, 700, although I guess you expect some of those are going to be knocked out as false positives? That's right. When we see these candidates, we know that some of them are going to be stars that graze one another, stars that are eclipsing binaries in the background. So we know there's always a fraction, like something of 50%,

that turn out to be not planets. And that's why when we announced those five, they were confirmed. We made all the measurements from the ground to confirm what the telescope in space had seen. And that's what we're doing this summer. We're going through these hundreds of candidates trying to confirm, I don't know how many will be successful, but at least several dozen, and maybe even more than that, depending on how the weather is and how well the telescopes work for us. What allowed you to advance from five in January to

over 700 now? Although, as we said, not entirely confirmed. That's the big difference. In science, you're trying to have proof, you're trying to have evidence. And so the fact that you've got an interesting clue, which is what they are, there's 700 clues that they're made by planets. We like to call them candidates, but if you'd like, call them clues. Until we make the measurements from the ground, we don't know that any of them are planets. They could all be false positives.

We don't believe that for a second. But the point is, we want evidence that these really are planets and not something else. And only then do we say they're a discovery. Only then do we make an announcement. Only then do they go into a journal paper that's refereed. So we have five planets that are confirmed. We have no more than that.

The rest of these 700 are candidates. But we feel very good about these candidates. We have taken 300 of them and given them to the public, to the science community and said, we don't have time to look at all these. Why don't you take these 300 and we'll tell you what stars that we have clues about, what time we think the transits occur, how big the planets are, how bright the stars are. Give them all the information so they can help make these discoveries. But until those confirmations come in, we have no more than five discovered planets. I remember you telling us in January that a big part of the confirmation looks to

the work of other scientists, other astronomers, using an entirely different technique for detecting these planets. That's exactly right. What we're doing with our transit photometry is looking at an object crossing a star, blocking some light, so we measure the brightness of over 100,000, in fact, over 156,000 stars, looking for these changes in brightness due to a planet crossing. But to confirm this, that it is a planet crossing, not a small star, for example, we go to the ground-based telescopes in Spain, in the United States, in the island of Hawaii.

All these different places have telescopes, and we look to see, is there a change in the motion of the star? That motion of the star is new confirmation that, indeed, there is a planet there perturbing the star, and by making it move slightly as the planet orbits around the star. And so that's an independent confirmation, and it's certainly enough, particularly if we go and do another step, which is look with telescopes that have what is called active optics, where you take special measurements through a telescope

to see if there's any other star really, really close to your star that might be diluting the light from the star, or might be a false positive, might be an eclipsing binary. So this is called active optics, and it is done by several of our telescopes as well. So we check to see that we get these radial velocity changes. We check to see if there's no other star that could explain it. And then we say, okay, this is a confirmed planet. Those of these findings that turn out to be false positives,

if they end up being identified as binary stars, isn't that still pretty significant? Yes, it is. Actually, binary stars are extremely interesting in many different ways. In fact, most of the stars in our galaxy are binary or trinary, sometimes quadruple star systems, very complex star systems. And if you were orbiting them, you would see two stars in the sky that would rise and set at different times, or three stars in the sky. It would be just a much more exciting thing to get up in the morning and wonder which star was up, which sun was up.

So, yes, they're very valuable. We have a large group of people that study these on their own, because it's a great way to understand how stars are formed, how they age, how they change size. It's been considered the royal road to understanding stars because you get so much information from binary stars. One of the other interesting things that I found, and this is actually from an article by my colleague Amir Alexander with the Planetary Society, Amir Alexander with the Planetary Society, is that there's, I guess, a good chance that some of these systems you may have developed really are systems, multi-planet systems. What's the significance of that? We certainly have evidence, and we've shown some of this evidence in the paper that we're

putting out, where we have stars that have two or three planets, or really planet candidates, orbiting them. The nice thing about that is, first of all, you're beginning to understand planetary systems, not just a lone planet going around, but systems of planets. How do they interact with one another? And in fact, the fact there's more than one also means that as a planet comes close to another planet, it speeds up and the planet's overtaking slows down a little bit. And so you can use that kind of information to determine the mass of these planets.

And that's important because as the planets get smaller and smaller, we look for planets closer and closer to the size of Earth. The radio velocity work that we're talking about at the big telescopes will not be sufficient. We will have to use other techniques to confirm these small planets. When you get to planets the size of Earth, they're very, very small, very low mass, so we need something new, and this is something that will be a huge help to us in terms of saying, yes, indeed, that is a small planet, that is an Earth-mass planet. That's Bill Berucki, science principal investigator for the Kepler Exoplanet Discovery Mission.

He'll tell us more when Planetary Radio continues. the solar system. It searches for other intelligences in the universe, and it built the first solar sail. It also shares the wonder through this radio show, its website, and other exciting projects that reach around the globe. I'm proud to be part of this greatest of all voyages, and I hope you'll consider joining us. You can learn more about the Planetary

Society at our website, planetary.org slash radio, or by calling 1-800-9-WORLDS. Planetary Radio listeners who aren't yet members can join and receive a Planetary Radio t-shirt. Our nearly 100,000 members receive the internationally acclaimed Planetary Report magazine. That's planetary.org slash radio. The Planetary Society, exploring new worlds. Welcome back to Planetary Radio. I'm Matt Kaplan. Thanks to the Kepler mission, we should soon have confirmation of hundreds more exoplanets, and even whole systems of planets circling distant stars.

It is the crowning, yet ongoing, achievement in the long career of William Berucki, ongoing achievement in the long career of William Barucki, leader of the Kepler science team and a pioneer in the development of transit photometry to find other worlds. Another thing that truly amazed me about this announcement is the relatively short period of observation that allowed you to identify all these candidates. Does that say something about what's in store for the remainder of this mission? It certainly does tell us what's in store, but we need to think about it carefully, in that it's easy to find a planet near a star. And that's because no matter which direction you look,

the planet's going to get in your way and block some light from the star. And in fact, if the planet were right on the surface of the star, no matter where you looked, what angle you looked in the sky, you would see the transit. But as you move further and further away from the star, you have to get the alignment of your telescope and the planet and the star in a near perfect alignment. And so the number that we expect to find drops off very fast with the orbital size or the orbital period. So most of what you're going to see, you see fairly early. And so it's not surprising at all that in the first 43 days of data, we found over 700 candidates. And in fact, when you look at what we found, we found

closer to 950 candidates, but we were quickly able to show 200 of those were false positives. So we're only talking about the 700 or so candidates that we think there's a very good chance that they have a planet. So we found a lot of things early. We will be finding more things year by year. And in particular, what we find as the years go on are the most valuable planets, the planets that have orbital periods that have put them in the Goldilocks zone, the zone where you can have possible life, the habitable zone. When the temperature is not so hot, the oceans boil. And not so cold, everything is frozen solid forever.

So that's what we're looking for. We're looking for longer periods where we look at the data for a year or two years, or really three years, to get three transits to confirm the period. But three transits in a habitable zone means you have to look for three years. Our mission's only been up for one year, so the chance of finding something in a habitable zone is essentially negligible until we get more data. How about some of the planet-finding instruments that are just over the horizon now? I'm thinking of things like the Terrestrial Planet Finder.

Is Kepler paving the way for those? That's exactly right. Kepler is a step in our exploration for life on our galaxy. And the step tells us, are Earth frequent? Do many stars have Earth? Do they have them in a habitable zone? If the answer is yes, then the next mission goes out and says, I will measure the atmospheres of those planets.

I'll see if they have oxygen in them. I'll see if there are any life signs in those atmospheres. The National Academy of Sciences said, well, there's two ways to do that, and Kepler needs to tell us. Are there lots of such planets? If there are, we can use a system called occultation. You take a telescope, take the image of the star, you put it on a little black disc. The light from the star is blotted out,

but now you can see the stars around, the planets around it, and get their spectra, understand their atmosphere. Sounds kind of like a chronograph for studying the sun. Exactly. It's very, very much like a chronograph for studying the sun. But it's bigger, it's more expensive because the stars are so much fainter, so much further away. The other way that you can do it is to use an interferometer, and that is you use a series of telescopes, and you bring their light together with extreme care, and you block out the light from the star that way, and again, the light from the planet shows up, and you can, again, measure the atmospheric properties. Those methods are two different methods. They're both very expensive, and so we need to choose the one that will work the best.

And the one that will work the best, if there's lots of planets, is the occulter. If you have to look much further away, there's very, very few planets, you have to look much further into the galaxy, then an interferometer looks like it's the best bet. Bill, we're just about out of time. Can you tell us when we might look forward to the next data from Kepler? We're putting together some papers to describe some of the things that are being discovered even now. And so we expect to see that later this summer, a few.

But we'll have the entire summer to make these observations. And so certainly at the end of the winter, probably in January or December or January, you'll see many, many discoveries come out. I hope we can keep checking back with you, especially as you approach your 50th anniversary there at Ames. It's been a while. Thanks so much for joining us again on Planetary Radio. You're most welcome. I've enjoyed it. William Barucki is a space scientist at NASA's Ames Research Center. Of course, we have been talking to him about his role as the science principal investigator for the Kepler mission,

which has been unveiling planets circling other stars as no other instrument has ever done so before. In fact, my colleague Amir Alexander called it, and I think very accurately, the most effective and efficient planet-hunting instrument ever built. We'll be talking with Bruce Betts during this week's edition of What's Up in just a few moments. Time for What's Up on Planetary Radio. Bruce Betts sitting across from me in the conference room, the library here at Planetary Society headquarters, ready to tell us about the night sky and later for both of us to tell all of you folks who we're going to help buy their own space shuttle.

Welcome back. Could be back and can hardly wait. Got that T-shirt and eight dollars and 17 cents waiting for somebody burning a hole in your pocket hit us with the night in the night so in the evening sky in the west that's where the party's happening we've got venus looking like an extremely bright star-like object to its upper left is regulus the brightest star of leo to its upper left mars looking reddish and then to its upper left sat Regulus, the brightest star of Leo. To its upper left, Mars looking reddish, and then to its upper left, Saturn looking yellowish. But Venus and Regulus, they start snuggling. So by

July 9th, they are just very snuggly close together in the sky, Venus being the much brighter object. So all sorts of things happening, and if that wasn't enough july 14th i have arranged for there to be a crescent moon near venus and july 15th near mars and saturn you are a kind and generous ruler why thank you and also you can check out these days the as we move into summer nice constellations over there in the south i mean all over the sky but scorpius sagittarius looking cool scorpius its brightest star looking kind of reddish kind of mars like and that would be anteres look in the south in the evening sky the reddish fairly bright star is anteres onto this week in space history had some big launches mars rover opportunity launched in 2003 this week. Voyager 2, actually, not a launch.

Voyager 2 went cruising past Jupiter in its first big giant planet flyby in 1979. Also, Doc, this week, 1979 Skylab reentered the atmosphere. Which brings me to Random Space Fact, Random Space Fact, Random Space Fact, Random Space Fact, Random Space Fact, Random Space Fact, Random Space Fact. That's a wonderful, entirely new approach. Antares. I may have mentioned that once or twice before, like just a little bit ago. Antares, the brightest star in Scorpius. This is interesting.

All these years referring to Antares and saying it was reddish, I never got it. Ant Ares. Oh. This is interesting. All these years referring to Antares and saying it was reddish, I never got it. Ant-Aries. Oh. Derives from the Greek for against Mars. Aries. Mars. Fascinating. In Greek, due to the similarity of its reddish hue.

Hue. Reddish color. And it's also this massive super giant towards the end of its life, and someday it's just going to go out and we won't know for a while. Yeah, the Greeks knew that too. Really? Man. They knew a lot of stuff.

Let us go on to the trivia contest because I know you got a lot of good stuff for us. Yeah. This was really your inspiration. The space shuttles, NASA apparently going to sell off the space shuttle fleet for what, 20? 28 million. 28 million a pop. That includes shipping. Really? Yeah. Oh. So we asked you to tell us why should we help you with our massive $8.17 collection, help you to buy one of the space shuttles. And we got some great entries.

Tell us about them, Matt. I'm going to work up toward our winner, okay? All right. And once again. Suspense building. You guys are so good. And we wish that we could give attention to every single one of them. And we're going to work on finding a way to do that.

But we only have time here. We don't even have time to mention this many. But we're going to do it anyway. Lots of great entries. Thank you so much. So here goes. Torsten Zimmer in Germany. I'm just going to read pieces of these. Why does he want a shuttle? Because he's working on a

remake of James Bond, Moonraker. Which is, you remember that one? The shuttle had the laser in the nose. Just like the actual shuttle. Why did they cut that from the budget? Why did NASA lose that? That's so cool.

Susan Noe, she just wants the shuttle for parts. You would suggest her once putting it up on blocks except in space next to the ISS. She needs the parts for her other shuttle. And somewhat related to that, Doug Pickle, he said he wants our help buying a retired space shuttle so no one will notice his other vehicle is a gremlin. And our condolences. Indeed. All right, we're up to our runner-up, and we can't possibly do this justice. People hear us talk about Lindsay Dawson. Lindsay is just amazing. He sends us all these great deep science answers to our trivia all the time. Well, this time, from all appearances, he went to the Chamber of Commerce in his hometown of Cobar, Australia.

And he's got a full proposal here. Here are the pages being turned with photos, illustrations of why Cobar should be the home of the shuttle. And we can land it on Main Street. Exactly. Save that shipping, just land the last shuttle on Main Street. Now, there were some issues, as you pointed out, with the length of Main Street. But you pointed out a great alternate landing site just outside of town, apparently hundreds of miles of straight road to land on. Great job.

Tell the chamber we will be happy to put in a good word. I enjoyed the Google Earth view of what the shuttle astronauts would see as they were coming in towards Main Street. You ready for our winner, though? I'm so ready. Randall Sitton. Randall, longtime listener to the show, happens to also be a charter member of the Planetary Society, but we swear that had nothing to do with this. He gave us not one, not two.

He gave us the top ten reasons why he should get help getting a shuttle. Can I just read a couple of these? Read a couple. Okay, here we go. Number seven, he could use it to tailgate at University of Houston football games. Number six, I could have a real space shuttle and not some fake full-size replica. Number four, I could use its robotic arm to hang Christmas lights. Ooh, cool. Okay, and here is his number one reason. It would make a great home for retired staff and charter members of the Planetary Society. So, obviously.

Oh, we love that. Randall, congratulations. The $8.17 is almost in the mail with your Planetary Radio t-shirt. Congratulations. And really, again, great entries. Thank you all. This next time we return to a more or less creative subject, but I think of interest, which is how much total lunar material was returned by the Soviet Luna Robotic Sample Return Program.

So they had a robotic sample returned from the moon. How much material, how much mass from all of them was successfully returned to Earth? Go to planetary.org slash radio. Find out how to enter. You've got until July 12th, Monday, July 12th at 2 p.m. Pacific time to get us your answer. All right. Everybody go out there, look up at the night sky and think about beautiful roses like surround us now in our new takes. They really are.

Good night. Those are federal roses too, aren't they? What happens if we pick them? Do we have to be brought up on trial in that building next door? I went to pick one, and I noticed this little laser dot on me. So I opted to just enjoy it from a distance. Maybe they did build those shuttles with the lasers in the noses.

All right, say goodnight. Goodnight. He's Bruce Betts, the Director of Projects for the Planetary Society, and he joins us every week here for What's Up. A return to the ongoing search for extraterrestrial intelligence. SETI, next week on Planetary Radio,

which is produced by the Planetary Society in Pasadena, California, and made possible in part by a grant from the Kenneth T. and Eileen L. Norris Foundation. Keep looking up. Редактор субтитров А.Семкин Корректор А.Егорова