Planetary Radio: Space Exploration, Astronomy and Science - Searching for Pandora With Debra Fischer

Episode Date: April 9, 2012

Yale exoplanet hunter Debra Fischer is about to begin looking for worlds in the star system that is nearest to Earth. She'll tell us about new technology enabling this effort, and how you can join the search.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Hey, podcast listeners, it's one of those infrequent special messages, secret messages that we have just for you guys. We leave out the radio folks because there are more things we can say to you, quite frankly. And this is the first of these that we're attempting with a guest. Deborah, are you there? I am. Thanks, Matt. Deborah Fisher, you're going to hear her in a few minutes for the regular interview segment on the radio show, to hear her in a few minutes for the regular interview segment on the radio show, talking about some very exciting stuff in her ongoing search for exoplanets, those planets circling other stars. In fact, with this one, it's particularly exciting because Debra is going

to be looking, we hope, for a planet in the nearest star system to Earth, the Alpha Centauri group. Debra, the reason I wanted you to be part of this little special message is because we're about to make a new appeal out of the Planetary to support your work. And what is this about? Are we going to help you buy time? That's right. It's much appreciated. Yes, indeed. The advantage that we have with the Chiron spectrometer at Ceratololo is that we have the possibility of buying 200 nights or more per year.

The funding for this time can't be purchased with federal grants. NASA invests in space missions. They do fund projects at Keck, but they don't allow and the NSF does do not allow the purchase of ground based telescope time. This is a project that's near and dear to my heart. I'll say I've been working on it long before I was able to convince anyone to give us funding for the project. And I'm still working on it. Yale University is very generous, you know, with the setup support that they provided to my team. And so I've been using my own funds to buy telescope time.

And I'm hoping that if listeners find this search appealing, that they might be willing to contribute. And that's why we're putting out this special message to you today. You can learn more by going to exoplanets.planetary.org. And those of you who would like to help make, who knows, we won't know until we look with Deborah's advanced hardware to enable us to make this possible. We won't know if there's a Pandora planet, not a moon in this case, because as you'll hear, we know there isn't a planet big enough to be the Jovian planet that Pandora circled. But if there's a Pandora out there, that's what Deborah and her team hope to find with this. Again, you can learn more at exoplanets.planetary.org.

And those of you who are willing to put in a few bucks to buy some telescope time, you'll get some things out of that. I think we'll be sending you a certificate. Deborah, thank you. We'll talk to you again in a few minutes during the regular show. Thanks so much, Matt. And for all of you who are faithful listeners to the podcast, thanks so much. Sure are glad to have you around. And here is Planetary Radio.

Searching for Pandora with Deborah Fisher, this week on Planetary Radio. Music Welcome to the travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society with a bit of a cold. What would it mean if we found a near-Earth-sized world circling Alpha and Beta Centauri, just a bit more than four light-years from our own planet? Deborah Fisher and her team hope to find out. We'll talk with her about a new long-term examination of this binary star system using cutting-edge technology.

Bill Nye, the science and planetary guy, will tell you how to become an official space geek, while later in the show, Bruce Betts will draw lines across the sky that make it easier to find several very cool objects. First, though, a visit with Planetary Society blogger Emily Lakdawalla, who apparently won't be seeing John Carter in a movie theater anytime soon. Emily, I have been to Parsum. I'm envious. I haven't been to a movie in like six years. Oh, you're joking.

No, I'm not. I remember young children. I remember having young ones in the house. Well, you know what? It's not half bad. I can actually recommend it, and I feel bad for Andrew Stanton,

who's a lovely man, the maker of this movie, co-writer and director, and it's a fantasy, of course. It's either a fantasy or Mars is much less massive than we've been led to believe. Because you can jump really far on Barsoom. I've always wanted to have that particular skill. Well, I thought it was a nice movie.

Speaking of the arts, you have poetry in the blog. I do. I have poetry from Andy Rivkin, who is by day, he is a mild mannered asteroid astronomer who studies the surfaces of things in the asteroid belt to see if they have primarily to see if they have water on their surfaces. But he has taken up the challenge of National Poetry Writing Month, which is the month of April. And his first entry, I have to say, is really pretty awesome. It's about a favorite moon of mine, Iapetus. And honestly, you just have to go read it. He's actually posted, the day that I posted the

Iapetus one, he also posted one about Titan that I really enjoyed. Yes, you should read it. And it's an April 5 entry in the blog at planetary.org. But I got to read at least the first line. Two-faced orb, more Janus than Janus. Yeah, I've always thought that Janice was a name that was wasted on that tiny little moon close to Saturn. It really needs to be the name for Iapetus. They just ought to switch. It's just wrong. Are you listening, IAU? Light and heat separate soot from frost in a place where tons are pounds and Roland's song still echoes. I'll leave it at that. You've got to go to the blog for the rest. Little tease there. Now, turning to something that hasn't appeared in the blog yet, but maybe soon.

Yeah, that's right. In the last week, there have been two data releases, and data releases are where a mission has spent its proprietary period figuring out, making sure that the data is of high quality, and then they put it into what's called the Planetary Data System, which is NASA's library for spacecraft data. And so there has been a recent data release from Cassini. They do data releases four times a year. And this one includes some really gorgeous pictures of Helene, which is a very tiny moon with some strange landslide features. And then the European Space Agency has released the data from their Lutetia flyby by the Rosetta

mission. And Lutetia, at the time, it was the largest asteroid that had ever been visited by a spacecraft. It was almost immediately superseded by Vesta. But still, it's really quite an amazing asteroid. And that one, I haven't had time to get into yet. And I really can't wait because it's a fascinating world in between the tiny asteroids and the great big nearly planets like Vesta. So I'm looking forward to dealing with that. Well, who knows? Maybe some of this will be in the blog by the time people hear this,

since we're recording a little bit early this week. Check it out at planetary.org. And Emily, I will talk to you again next week. Thank you, as always. Looking forward to it, Matt. Emily Lakdawalla is the Science and Technology Coordinator for the Planetary Society and a contributing editor to Sky and Telescope magazine. Here's Bill. Bill, once again, we talked to you as you've returned from the road, a couple of college visits. Yes, Southeast Missouri University and University of Colorado, Colorado Springs. The Red Hawks and the Mountain Lions, Matt. And may they ever be victorious. What'd you do?

I spoke about our place in space. This is to say, when you compare the Earth to anywhere else, the Earth should be your favorite planet, pretty much. Yeah, pretty much. And we have now 7 billion people living on this earth where if you had some extraordinary vehicle with an extraordinary highway and you could drive straight up, you'd be in outer space in an hour and a half. And that atmosphere is so thin that the 7 billion people have been able to change its chemistry. And this is what the college students of today are going to have to deal with tomorrow. And then I went on, Matt, you know, as CEO of the Planetary Society,

I did happen to mention the opportunity for the college students to become space geeks by sending an email address. They can get a space geek button. It's very exciting. And then I hope everybody will get involved in this Earth Dial project. You know, when the Curiosity rover lands on Mars, another sundial, the third Mars Dial sundial, will be casting shadows. And I'm hoping to get worldwide participation in the Earth Dial project, which really helps you understand how diligent

our ancestors were, the astronomers, who figured out how to get a calendar to come out perfectly with a correction needed every 3,000 years. That's pretty good. Yeah, they did good work, even without lenses. Most especially without lenses, just looking at shadows. Can anybody send in and get a Space Geek button? Planetary.org slash Space Geek. And we will put that up at Planetary.org slash radio, where you might even be listening to this show.

Thanks, Bill. Thank you, Matt. He's the CEO of the Planetary Society. And we'll be talking with Deborah Fisher about her work that she's doing with the Planetary Society in a moment. I've said it before, when I was a kid, the textbook said we'd probably never detect a planet across the interstellar gulf. Now we've detected hundreds and hundreds, and our instruments become ever more sensitive.

Yale University astronomer Deborah Fisher has devoted her professional life to this search, and now she hopes to look to our next-door neighbors with an unprecedented level of precision. When we talked a few days ago, she had recently returned from Chile, where she and her team are preparing a telescope that will stare long and hard at the star system where James Cameron put his magical moon of Pandora for the movie Avatar. Deborah, always a pleasure to talk to you, and I'm glad that we can check in and see how the search for planets is going. Hi, Matt. Thanks so much for having me. Not surprisingly, I think a lot of people, including myself, are going to find this latest project especially exciting because we're all thinking of very tall, blue-skinned people living on, well, of course, it was a Jovian moon out there at Alpha Centauri in the movie Avatar. Even if you don't find Pandora, it's awfully exciting to think of looking this close by, isn't it?

Absolutely, and that's exactly why we're going after Alpha Centauri A and B so hard. This, of course, is a binary star system. Well, it's a triple star system, if you count Proxima Centauri, which is quite far away from the two stars that we're focusing on, Alpha Cent, A and B. But they're our nearest neighbors. They're just four light years away. So if we phone them, then the pause that you hear on the satellite phone lasts for four years. But that's closer than any other star that we're studying. Yeah, certainly beats hundreds or thousands. Exactly. Why is this search now being undertaken now? I mean, it seems like people would have been looking at Alpha Centauri for as long as we've been able to detect exoplanets,

or is it just that we weren't sensitive enough to find what might be there? Absolutely. Alpha Centauri is a prime system to look at. And the one key is that you have to be in the southern hemisphere. That's where the stars are visible. They're quite close to the South Pole, in fact. The other key, of course, the Geneva team with the HARPS spectrograph is looking at Alpha Sen, but they're also looking at thousands of other stars. Our feeling is that what we're doing is an extremely high cadence observing strategy, meaning that we have 200 nights of telescope time per year. We're going to devote a significant amount, fraction of time each of those nights

to the AlphaSense system. And so just by the sheer number of observations that we can collect, we think we'll be quite competitive. There's another facility in New Zealand where astronomers have been looking at AlphaSense and also in Australia. But it's the same situation that we're trying to do something extraordinary. Unlike the wonderful movie Avatar, where Pandora orbited a Jovian moon, we know that that Jovian planet doesn't exist. So we've looked long enough and hard enough that we can rule out several large planets. And that could be good news or bad news, depending on how you see it. And that could be good news or bad news, depending on how you see it. I think it's good news. It means that the habitable zone around

both Alpha Cent A and B are wide open for rocky planets. So if Pandora's out there, it's going to be on its own. It's on its own, right. And to follow up, you asked, you know, why is it possible now? I think it's, we've been working for the last few years, as several members of the Planetary Society will know. We've been developing new kinds of instruments and in particular fiber optic feeds to scramble the light so that it goes in and illuminates the optics in exactly the same way. And this is really giving us a leg up on improving our precision. So this is this FIND system, which we've talked about in the past, fiber optic improved next-generation Doppler search. Why is it useful to sort of scramble this light coming through the,

or coming to the spectrometer? Right. Of course, in the olden days, historically what we've done is we've just had a slit, and the light goes from the telescope and focuses on the slit, and then it goes into the instrument. And that slit, the width of that slit, sets the resolution of the spectrograph. And that was fine until we realized that because of seeing and guiding of the telescope and everything else, the light cone that went into the spectrograph was changing wildly from second to second. So the very first optics inside behind the slit see a sort of light show, right, that's flickering and varying. And one

spectrum is not going to be exactly like the next spectrum. So that ends up being a source of systematic error in our measurements. And what FINDs does, the fiber optic scrambling system, is it makes sure we ensure that we have very constant illumination of the optics independent of the way that the light goes into the fiber. And that allows us to improve our Doppler measurement precision. Were you able to prove out this technology with the first FINDs instrument at the Lick Observatory? Indeed. We have now both a book chapter and a couple of papers that describe our findings showing a remarkable improvement in what we call the point spread function.

It's basically the stability of the light as it's going into the spectrograph and an improvement in the velocity performance, which is what we really care about. So we want to take this and basically put it on steroids and really boost things, the stability of our instrument. The instrument that we're using, Chiron, is an instrument that my team has built and commissioned at the Cerro Tololo Observatory in Chile. And we have achieved remarkable precision.

Our individual error bars are only 30 centimeters per second. But from night to night, there are systematic errors. We were able to keep those down to under a meter per second, something like 89 centimeters per second was the RMS over a few weeks. And we've just completed some upgrades to try and push that stability even further. You had mentioned early in the conversation, needing to get down to, I think you said, about a centimeter per second to be able to see, maybe not quite Earth-sized, but close to

Earth-sized planets around a star like Alpha Centauri. What does that actually mean? I know it has to do with the Doppler effect. Yep. I'll just be honest. We have no idea how to get one centimeter per second precision right now. We are fighting centimeter per second at a time to try and push things down. And with that strategy, we've gone from achieving a precision of about, you know, two or three meters per second, two or three hundred centimeters per second, down to about 80 centimeters per second or 0.8 meters per second. So to get down to one centimeter per second, it's like imagine a little caterpillar moving along. It's about as fast as a caterpillar crawls. What that means technically is that we're looking at absorption lines from the star. We have a CCD detector, just like most people have in their digital cameras, and we're watching the lines wobble back and forth as the star goes away from us and then

comes toward us. Now, that might sound easy, but the sorts of shifts that we're looking for, even for two or three meters a second, correspond to something like a couple hundred silicon atoms or one one-thousandth of a pixel. Doesn't sound easy at all. It sounds like exquisite sensitivity to me. Yeah, it's attention to detail. And there are now a thousand things that can go wrong, and if we get 999 right, it's not good enough. More from exoplanet hunter Deborah Fisher is coming right up,

including how you can join the search. This is Planetary Radio. I'm Robert Picardo. right up, including how you can join 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. Astronomer Deborah Fisher will soon begin staring at Alpha and Beta Centauri with the telescope in Chile. That telescope has the Chiron spectrometer built by Deborah's team at Yale. It just might enable them to determine if there is a planet or planets orbiting these two nearest of stars to our own. But this is hardly the only search she is involved with. As you'll hear from Deborah in a couple of minutes, you can help analyze data from the Kepler spacecraft that could get your name added to a paper announcing the discovery of an exoplanet.

But first, that scope in South America. Well, what is special, if anything, about this telescope in Chile? It's not particularly large, is it? No. Fortunately, Alpha Centauri are such bright stars that we don't need the telescope to be large. Our exposure times are measured in seconds, something like 15 seconds or 30 seconds. But what we needed was a lot of telescope time

to pound down our errors and to explore where systematic errors were creeping in and and that's what we have with this telescope in fact when we started you know looking the telescope was about to be decommissioned and we were able to come in and rescue it and then get funding from the NSF to build the spectrograph. So we're just now, in fact, tuning up the recommissioning with all of the upgrades and are getting ready to go again. It's the fact that we have access to 200 nights of time per year. We have nothing close to that on any of our other telescopes. And I know that the Planetary Society is hoping to help you

to buy some of that telescope time. How has the Planetary Society's assistance helped in the past? Because I know you've gotten much more funding from other sources. Absolutely. And I think, you know, the Planetary Society funding actually helps us to bootstrap into other successful proposals. Because when reviewers are reading our proposals, they want to see that we can actually do what we say we're going to do. So what we've been working on are prototypes that have been built with funding generously provided by the Planetary Society members. We then have a demonstration, a proof of concept, so that enables us, if we get $30,000 from the Planetary Society,

it enables us to leverage that and get $300,000 or $400,000 in funding from other agencies. Fill me in just a bit of an update, perhaps, on the work that's being done by you and your associate, longtime associate Jeff Marcy, for what's being called FINDS-2 at a much bigger telescope. Right. We've started working on a fiber scrambler for the high-res spectrograph at Keck. And the beauty there is that the Keck telescope, the Lick Observatory telescope, is on a mountain at about 4,000 feet. The Keck telescope sits at 14,000 feet above sea level. It's between zero and three degrees centigrade there all the time. So it's a more stable instrument.

It's a more modern instrument. And we're right now in the lab working on a prototype fiber scrambler for high-res. And we're very excited. We think that we're going to see some remarkable improvements there. Last thing I want to ask you about. I know that you are another scientist who has been very excited about citizen science projects. Tell us just a word about your involvement with planet hunters. Right.

When we saw the Kepler data, public release data in 2000. The Kepler spacecraft that has been giving us good indications of so many hundreds of possible exoplanets. Absolutely. It's rewriting all of the, everything we know about exoplanets. And when I first saw that data, I had actually sent some of my graduate students to Caltech to participate in a Sagan summer school. And I realized that this is, it's very tricky, but the human brain is so great

at pattern recognition that I came back and we teamed up with Chris Lintott and the whole Galaxy Zoop to develop a citizen science project where we serve up the Kepler data in what we think is a very user-friendly format. And we have the public go in and if the public classifies even 10 or 20 light curves, it helps us immensely because collectively there are so many people that are working on this that we now have the equivalent of one person sitting down for 200 years working 24-7, never taking a break and looking at nothing but Kepler light curves and analyzing them. That's what the public has done with this great PlanetHunters.org citizen science project. So they've been amazing in filtering through the entire Kepler database, and we've discovered more planets because of them. The public, in fact, are co-authors now on three papers that are being published. That's great.

Yeah. How do you give a credit on a paper to the public? Well, no. The finders actually are named. They're co-authors. Oh, that's fantastic. The individuals. Exactly.

Wow. Deborah, it's exciting stuff, and it is always exciting to talk to you and others like you who are literally discovering new worlds. Thank you so much for joining us on the show once again. My pleasure. Thanks so much. And if you want to learn more, well, we'll have lots of links up at planetary.org slash radio, like to planet hunters, but also to learn more about the exoplanet work that Deborah is doing, finds, too, in this new effort to find, all right, well, I'll just call it Pandora because I'm sure somebody's going to ask the IAU to call it that when we find that world that might just be in that binary system out there at Alpha Centauri. Deborah, by the way, is a professor at Yale. She has a joint appointment in the Department of Geology

and Geophysics. She's still an adjunct professor of physics and astronomy at San Francisco State University. And her research, as you can tell, is all about the detection and characterization of exoplanets. We'll take a look up at the night sky with our friend Bruce Betts. That'll be for this week's edition of What's Up in just a few moments. Time to close out as we always do with Bruce Betts, the Director of Projects for the Planetary Society. This is What's Up. We're doing this a little bit early because I'm looking forward to a weekend off. And hopefully there'll be clear skies where I'm going so I can enjoy what you're about to tell us. Is it on this planet? Yeah. But speaking of other planets, and in fact,

I've got a new game for you. So we're going to play Connect the Dots in the night sky. So in the early evening, look to the south and find Orion. And Orion's belt, those bright three stars right next to each other, many people have learned to find. As always, if you go one direction, if you go off to the left, roughly you'll point towards the brightest star in the sky, Sirius. If you go off to the right on that line of Orion's belt, at a point kind of above the line, you'll come to a sort of reddish star

called Aldebaran, the brightest star in Taurus. But what's different in Spiffy Keene is you will come to Venus. So you got a line connecting the brightest star in the sky with the brightest star-like object in the sky. How cool is that? That is pretty cool. Thank you. Now, it's not an exact line,

just for those sticklers out there. We'll mention one other thing, which is Venus is hanging out near stars that are, of course, always nearly on that line, which is near Venus, below Venus, the Pleiades star cluster. So a little cluster of faint stars all together. Subaru. We also, of course, still have Mars looking pretty bright and reddish. Mars over in the east in the early evening sky. Oh, yes. You mean Barsoom. Yeah. Yeah, that's what I meant. Place of the big scary creatures and stuff.

The green ones, they're kind of sweet, actually, when you get to know them. Okay. Isn't that so often the way? Saturn coming up in the east around sunset because Saturn is at opposition on April 15th. Technically best time to be looking at Saturn because it's closest in its orbit, although percentage-wise it's not a huge difference, but it's something. So check out Saturn in the east or right overhead around the middle of the night. the east or right overhead around the middle of the night. We also have peaking on April 21st and 22nd, the Lyrids meteor shower. This is kind of an average shower, usually producing about 20 meteors per hour at a dark site. The good news this year is it's happening close to new moon, as with most showers, better after midnight. This week in space history was the first flight of a human in orbit. Who was that, Matt?

Barsoom? No, it wasn't anybody from Barsoom because they have a better way of doing this. But the Tharns do anyway. Our hero, Yuri Gagarin. And Yuri's night, of course, is this very week. Are those two correlated? Also, 20 years after Gagarin's launch in 1961 was the first launch to space of the space shuttle. In this case, the space shuttle Columbia.

We move on now to Random Space Act. Am alien crawling away from his crashed uh flying saucer and on an earth desert and he's saying ammonia uh yeah so anyway in the the Saturn system, Titan has about 96% of the total mass of the moons in the Saturn system. Wow. Really, really dominates the mass, despite having cool, fun moons like Iapetus and Linus. Titan is by far the big, massive beast. Speaking of massive moons, because we've had so much great stuff up in the sky, let's hurry on through the contest and talk about other moons. All right. We asked you, what is the fifth most massive moon of Jupiter? How'd we do?

Our winner, I think he's a past winner. I didn't really thoroughly check, is Karol Nowak or Nowak, he's from Lubin, Poland. He said it's Hamalia, or Hamalia, a moon of Jupiter. But you fooled a number of people because you did say mass. Yeah, you knew it. You said mass, not size, because apparently it's not in the same ranking in terms of size. It's not in the same ranking in terms of size. Yeah, Amalthea may or may not be bigger than Himalaya in terms of size, in terms of volume or diameter, but Himalaya gets the definite nod on mass. Of course, both of these follow far, far behind the four very massive Galilean satellites. Carol, you figured it out.

We're going to send you a Planetary Radio t-shirt. And I just want to mention very briefly that Ben Owens figured out that Himalaya is about five bajillionths the mass of Jupiter, 5.03 times 10 to the minus ninth. I was unfamiliar with the bajillionth unitth unit kind of education did you get there at stanford and caltech god all right next time i don't know for next time what is the source of the lyrids meteor shower the one i was just talking about peaking coming up here what is its source go to planetary.org slash radio find out how to to enter. And let me see. I think we'll give you until

Monday, April 16 at 2 p.m. Pacific time to get us that answer. All right, everybody. Go out there. Look up at the night sky and think about Matt's happy birthday. Happy birthday, Matt. Oh, you remembered. Thank you so much. And that's why I'm off to celebrate a little bit. And

the dogs next door are also celebrating my birthday. Isn't that great? That is great. You have such connection with the animal world. He's Bruce Betts, the Director of Projects for the Planetary Society. Down boys, down boys, there's cake for all. He joins us every week here for What's Up. Planetary Radio is produced by the Planetary Society in Pasadena, California and made possible by a grant from the Kenneth T. and Eileen L. Norris Foundation and by the members of the Planetary Society.

Clear skies and sinuses.