Planetary Radio: Space Exploration, Astronomy and Science - The Giant Magellan Telescope

Episode Date: August 9, 2010

Giant Magellan Telescope Director Patrick McCarthy. Emily Lakdawalla on Mars' acne. Bill Nye says a solar sail could test relativity.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

The giant Magellan telescope takes shape 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. It will dwarf every current optical instrument, including the twin kekais atop Mauna Kea in Hawaii. Patrick McCarthy is in charge of creating the GMT, one of a new class of super or extremely large telescopes. We'll visit with him at his base of operations. Emily Lakdawalla will reveal a new explanation for the bad case of acne on the face of Mars, while Bill Nye the Science and Planetary Guy will tell us how a solar sail may one day

test a weird prediction made by the theory of relativity. We'll close with a quick look at the night sky from Bruce Betts, recorded immediately after the Planetary Society open house a few days ago. Emily Lakdawalla gets us underway with highlights of the blog at planetary.org. Emily, good to see you at the Planetary Society's open house last week, especially with your 3D camera. Yeah, I had fun shooting 3D photos of all the people who came out. There are lots of members who came to support the Planetary Society

and a few big names like a certain Apollo 11 dancing astronaut, Buzz Aldrin. That was the first time I had actually met him, so that was exciting for me. Oh, really? Yeah, he was great. He had a nice little statement in support of the Society. It was fun to have him. And I got to move his car because he parked it in some federal judge's spot next door.

But let's talk about planetary science, beginning this week with these, you call them enigmatic little mounds that everybody's been trying to figure out what generates them on Mars. That's right. There are these little kind of pimply mounds that cover this huge region on Mars called Acidalia Planitia. It's a large low-lying plane in the high northern latitudes of Mars. And if you look at the geologic context, there are a lot of these huge outflow channels on Mars, all of which eventually empty into acidalia. So it's not a stretch to imagine that at some time there was a lot of water here, a lot of fine sediment. But now, of course, everything's dry. And as you zoom in and zoom in and zoom in on the images that we're getting from Mars Reconnaissance Orbiter, you see that these little mounds are everywhere and that they tend to line up along

cracks between huge polygonal fractures in the plains. And I just read this interesting paper that describes how because of the way that they're shaped and the way that they align along the cracks and the geologic context, they think that they are probably past mud volcanoes, places where gas and water and mud and rock spewed up out of the ground and made these tiny little mounds. There's tens of thousands of them across the northern plains of Mars. Are there parallels to these structures down here on Earth? There are. There are some on land, including I have a Google Earth image of some that are in Azerbaijan, but I think they're actually more common underwater in the ocean basins. Well, we'll put up a link to that at planetary.org on this week's show page. Just one other thing to mention, and that's another bit of your excellent work, taking images from a mission

and making them even more interesting, this time with the animation of some moons. That's right. I love it when Cassini captures movies of moons in motion. And of course, Cassini doesn't capture movies on its own. It just captures single frames, but the moons move in front of it. And all you have to do is stack the frames together and animate them. And this one was particularly cool because it was unusually close to some very small moons when it gathered this animation. So we see Prometheus, Epimetheus, Janus, and Atlas all crossing through the field of view. And we're close enough that you can see how Prometheus is through the field of view, and we're close enough that you can see how Prometheus is elongated, this two-lobed yam shape, and how Epimetheus has a nose sticking out of it,

and there's craters on Janus. It's a really fun little animation. Very cool work, Emily. Thanks once again for all you do and for joining us on the show. Thanks, Matt. Emily Lactuala is the Science and Technology Coordinator for the Planetary Society and a contributing editor to Sky and Telescope magazine. Here's Bill.

Hey, hey, Bill Nye the Planetary Guy here, soon to be executive director of the Planetary Society. And this week I have been thinking. My mind has been dragged around, if you will, from a lecture I heard a couple weeks ago at the International Solar Sail Symposium that Lou Friedman and I attended and presented our light sail project. I saw a couple weeks ago at the International Solar Sail Symposium that Lou Friedman and I attended and presented our light sail project. I saw a lecture by Roman Kirchhoff Ville. He's a big solar sail proponent. And he talked about an old phenomenon that's been theorized called frame dragging. So you have a really massive object like the sun, and you have a very, very sensitive instrument like the amazing accelerometers that are going to be on light sail one. And you get

an orbit around the sun, and there'll be a relativistic effect such that space-time is distorted, is dragged. The frame of reference is dragged. It seems slower to people farther away, faster to people closer, crazy things like this. And we could use our solar sails to detect this. We could show another aspect of relativity to be true. Or stranger still, show another aspect of relativity that you'd expect to be true to not quite be true, which would be even crazier. This is called the Lenz-Thuring effect, named after a couple of physicists who first talked about it back in something like 1918.

And this is an exciting thing. And if you're a member of the Planetary Society, it's another thing you're participating in. We are exploring space using the only propulsion technology usable for going between stars. I'm talking about solar sailing. It's the pressure of photons nudging very low-mass spacecraft through space. It's exciting. I've got to fly, Bill Nye the Planetary Guy. It's just a stately-looking building on a quiet street in Pasadena, California,

yet it has been the birthplace of several of the world's greatest scientific instruments. Another is taking shape there right now. The giant Magellan telescope is just one of the tremendous reflectors now being designed and built. is just one of the tremendous reflectors now being designed and built. Another, the 30-meter telescope, or TMT, is headquartered a few miles away on the campus of Caltech. Pat McCarthy directs the GMT project for the Carnegie Institution of Washington and an international group of partners. He took me into the parking lot to get a feel for just how big this new scope will be. There on the asphalt are six painted circles surrounding a seventh. Each of those circles represents one of the GMT's

seven mirrors, and each is 70 percent larger than the single mirror in the 200-inch or five-meter Hale telescope on Palomar Mountain. One of my favorite places on Earth is Palomar. And I have said to many people, including the audience of this show, you really don't get a sense of the scale of that instrument from any photograph I had ever seen during my entire life. The way you do when you show up there. This helps, but the scale of this compared to that instrument, the 200-inch, is just overwhelming. It is overwhelming.

So imagine, take one of these circles. These are 8 1⁄2 meters in diameter. Palomar is 5 meters. So you stand about here and to that edge, that's the Palomar mirror. So the scale is hard to comprehend. But an interesting fact I like to tell people is that Palomar, the moving weight of the telescope is 770 metric tons. The moving weight of the GMT will be 1100 metric tons. Now, that's less than a factor of two, but it's more than a factor of 10. It's about a factor of 20

gain in collecting area and only a factor of two increase in mass or weight. So that shows you that advances in engineering, computer-controlled drawing, finite element analysis allow you to build structures that are much more mechanically efficient. And the fact that the optics are very fast allows you to build structures that are compact. So we're gaining a huge factor in collecting area, less than a factor of two gain in mass and weight. And mass and weight translated to cost, performance, and so on. That's what makes this possible. If you scale the 200-inch up, it would be a behemoth like the pyramids, and it would collapse under its own weight.

You couldn't possibly do it. Pat, we've retired to this beautiful library part of the Carnegie facility here. There is a wonderful photo as you enter that kind of gives me goosebumps. Yeah, well, there's a lot of history in this library. Einstein spent a couple of summers here at Mount Wilson, back in sort of the critical days when cosmology was taking off, general relativity was just being formulated, and there's a great photo of him giving a lecture beneath the portrait of Hale, and Einstein is standing in front of a blackboard, and he's written an equation, r equals zero question mark, and he's asking, in essence, is the universe curved or is it flat? And that

has profound consequences. Will the universe expand forever? Will it collapse upon itself? Or will it actually be right on that fine dividing line in between? If you had asked Einstein at the time, the one thing he was confident is that it was not at that fine dividing line in between. He didn't believe the universe could actually be flat, in part because of the cosmological constant he invented and then discarded upon Hubble's observations. And now, of course, we've come full circle. The universe is flat. The cosmological constant rules or dark energy, we're not exactly sure which it is. And, you know, the history carries on, but much of it started here and

it's still going on. And this is just a wonderful bit of history and a nice piece of architecture here as well. It doesn't make much sense over the years for anyone to contest Albert's concepts, even Albert himself. It's generally not been a winning strategy. Really, it makes for quite an environment to be designing one of the great new generations of telescopes. Much of that work going on right here as we just saw as we walked around. That's right. This is a place with sort of much of the key history of American telescope building, and it's appropriate then that we're at the center or at least playing a crucial role in the development of the giant

Magellan telescope. The original large reflectors on Mount Wilson were all designed and built here. Much of the early work on the Palomar concept was done here. And the key observations of the expansion of the universe, the scale of the Milky Way galaxy were done here. So the key observations of the expansion of the universe, the scale of the Milky Way galaxy were done here. So it's not just Hubble, but it was Hubble, Bada, Shapley, people really, this was the core of American astronomy in the previous century. And we're hoping it's going to continue to be one of the key players in global astronomy in the next century. And the Giant Magellan Telescope is an essential part of that plan. So it's important for Carnegie, it's important for our domestic and international partners, and people here at Carnegie are thrilled that we're playing

a vital role in that project. Talk about where the project is now. I mean, it's only been in, what, a couple of weeks, maybe slightly more, that you announced another major partner. That's right. We were very pleased that the University of Chicago joined the project recently, and there's some interesting history there as well, of course. Hale came to Pasadena from the University of Chicago joined the project recently, and there's some interesting history there as well, of course. Hale came to Pasadena from the University of Chicago, where he had built the Yerkes 40-inch refractor, had designed and begun his early reflector projects. In fact, he brought that concept and some of the money with him from Yerkes to build the 60-inch at Mount Wilson. So it's sort of like an old family member now you've reunited with. So we're thrilled to have Chicago as part of it. They're a very strong group.

They have a very strong astronomy and a very strong physics department, and that brings a lot to the project. So we're thrilled to have them join us. And we think that we really built a partnership that's very strong domestically. We have many of the key and prominent U.S. universities, but having our international partners in Australia and Korea is essential as well. Australia has a really long and proud tradition of astronomy, and they're known for doing an awful lot of science on relatively few resources, and that's just that kind of spirit we want to bring to the GMT. What's special about the GMT? Well, in a

generic sense, you gain two things by building a very large telescope. You win by collecting more light, because as astronomers, we always want more light, whether we're dividing it into finer, finer wavelengths, or looking in greater detail, looking fainter, which in some sense allows us to look further away, but often just allows us to look for objects that are intrinsically less luminous. So the collecting area is a big gain, and you win by the square of the diameter in that case. So when you double a telescope, you get four times as much light. The GMT has 10 times the collecting area of our 6.5-meter telescopes at Las Campanas in Chile.

That's what the Carnegie's principal facility is. So that's a big gain, a factor of 10 in sensitivity or a factor of 10 in collecting area. That's a huge step forward. But there's another dimension as well. That is, as you increase the aperture of the telescope, you improve the angular resolution. And that depends simply on the number of wavelengths of light across the aperture. So as the aperture goes up, you collect more wavelengths, you get finer angular resolution, provided you can defeat the blurring impact of the atmosphere. That is, if you go outside on a summer day and you look along a warm stretch of pavement,

you can see the images shimmer. That's due to turbulence and heat rising in the atmosphere, particularly rising off the pavement. But that phenomenon exists throughout the atmosphere, and it limits the resolution of the telescope. Once the aperture gets above about 20 inches or even less, about 12 inches, the resolution is completely limited by the atmosphere. In the past decade or so, and really in sort of the past five years, people have fielded so-called adaptive optics instruments that allow you to measure the distortions in the wavefront, that is the incoming light caused by the atmosphere, and cancel them out much in the same way as your noise-canceling headphones

measure the noise around you, put in a signal that's the exact opposite of those and phase-cancel them. We're phase-canceling the distortions in the atmosphere by modifying the shape of a deformable mirror on very short timescales. In one minute, much more about the giant Magellan telescope from Project Director Patrick McCarthy. This is Planetary Radio. I'm Sally Ride. McCarthy. This is Planetary Radio. I'm Sally Ride. After becoming the first American woman in space, I dedicated myself to supporting space exploration and the education and inspiration of our youth. That's why I formed Sally Ride Science, and that's why I support the Planetary Society.

The Society works with space agencies around the world and gets people directly involved with real space missions. It takes a lot to create exciting projects like the first solar sail, informative publications like an award-winning magazine, and many other outreach efforts like this radio show. Help make space exploration and inspiration happen. Here's how you can join 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. 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. We are visiting with the director of the giant Magellan telescope, Patrick McCarthy.

I invite you to visit our show page from planetary.org to hear my complete conversation with Pat and to accompany us on a fascinating nearly 15-minute audio tour of the Carnegie Institution facility in Pasadena, built in 1913 by George Ellery Hale. That's where the $700 million GMT project is managed. For now, we'll rejoin Pat in the Carnegie Library under Hale's portrait. Everybody gets caught up, of course, in the mirror, because size matters.

What about the other end of the telescope, the instruments? Have we seen the same kind of evolution with the instruments that actually deliver the images and science to us? Very much. In essence, the real gains in sensitivity that telescopes have seen in the last 20 years or so have come from two areas, primarily cleaning up the thermal atmosphere, the thermal environment in the dome to make sure the telescopes deliver the best images, but primarily from improving the instrumentation. Going from early days of photographic films, it had a sensitivity of about 1%, that is 99% of the light that fell on the photographic plate was lost.

They were inherently nonlinear, that is, you couldn't really derive quantitative information from them. So with the advent of linear detectors, digital detectors that have high quantum sensitivity, inherently non-linear, that is, you couldn't really derive quantitative information from them. So with the advent of linear detectors, digital detectors that have high quantum sensitivity, really have improved the gains and sensitivities of telescopes. And now, as we start talking about extremely large telescopes, the instruments themselves take on a scale, complexity, and cost that are comparable to the previous generation of telescopes. That is, the scale of an instrument from GMT will be on the order of that of the telescopes that we built in the 4-, 6-, and 8-meter era. So they're going to be technically very challenging,

but they're the key to analyzing that light that we've collected and fed to the vocal plane, but all the real scientific work happens inside the instruments. So much of a project like this, as George Hale learned in his day, is not so much science as inspiration and fundraising. Big challenge, right? I mean, I think you're now at about 35% of your goal that you'll need to put this instrument on that mountain in Chile. That's right. The technical challenges are very real and very serious, but they are tractable, and we have convinced ourselves that there are no fundamental technical limitations to building the telescope. The real challenge is, as you say, it's finding the money, and that means inspiring people,

whether it be philanthropists who are interested in supporting this, the general public who might wish to support this through public funding, and just raising enough awareness and excitement about it that it becomes sort of a self-generating proposition. As you say, we have identified or secured 35% of the funding, but I should clarify that in the sense that we have partners whose goals and intentions bring us to 100% of the total funding. The 35% refers to commitments that are, in essence, in the bank that we can draw checks against. So we're very confident that we will grow that 35%

to 100%. That's the intention of the partners. They're making every effort to raise that funding. So we're being very conservative about where we talk about the funding level. And I think the prospects of us getting there to 100% are very, very good now. Well, that makes sense. If they ran with tens of millions of dollars already, you'd think that they probably intend to see this through. Yes. For example, the partners didn't sign up and didn't have their university president sign without the intention of actually making this a success. There's just a level of when their business offices will allow that money to be drawn on, and that's where this $250 million figure comes from as a 35%.

And we hope to get to roughly our $650, $700 million figure shortly when we begin construction in probably sometime in early or mid-2012. Really, I guess it's sort of a family of telescopes of this class coming online that are so much more powerful than anything that currently exists. It's easy to say that we've been in the golden age of astronomy. I don't know. Are we headed toward a platinum age or a diamond age? Well, as I tell people, there's never been a better time to be a young astronomer, and I really wish that I was one again because the future in terms of the potential for new discoveries,

new technical capabilities has never been better. As you mentioned, there's a new family of what we call extremely large telescopes coming along, one based in Europe, two based here in North America. But in addition, there are new facilities coming along in space, the James Webb Space Telescope. And in the millimeter and centimeter wave astronomy, the U.S., Europe, and Canada are about to commission the next generation very large millimeter wave observatory in Chile, and that's going to open a whole new world of studying star formation, planet formation, anything that's cold or embedded in dust and cold gas.

That ALMA, Atacama Large Millimeter Wave Observatory, will just open a whole new window for us. And by GMT being located in Chile, allows a real scientific synergy. In essence, we're just down the street from them in a scientific sense. We're in the same latitude zone, same part of the sky. And so whatever they discover, we'll be able to follow up. What we discover, they will follow up. And the two working together will be greater than the sum of the parts, without a doubt. will be greater than the sum of the parts, without a doubt.

So what do you hope the GMT will accomplish for the body of knowledge about our universe, along with its sisters, and also how will it complement the Hubble, I assume, will be gone by then, but certainly the JWST, the James Webb Space Telescope? Well, I certainly hope that it discovers things that are completely unanticipated. That's why we build these new facilities is to learn what the universe really is about. And it's almost always the case that what we learn is much more interesting and clever and creative than anything we dreamed up to begin with. But we have some very specific scientific goals. We'd like to be able to directly image planets around other stars. We'd like to be able to directly image planets around other stars.

On the other hand, we'd like to look back very early in the universe and understand when did the first stars form, when did the first galaxies form, how was the universe put together, and how did it go from this nearly uniform sort of sea or soup of gas to what we see now once the universe is almost entirely empty space with a few islands of stars, galaxies, that you call them the island universes originally, in which we inhabit, and most of the space between is empty but filled with very hot, very diffuse gas. And working together, when the web telling us about the mid-infrared,

finding the sources, the GMT and the other ELTs actually measuring their spectra, chemical abundances, ages, and so on, really unlocks sort of the mysteries of the early universe. And I sincerely hope and expect that we'll find out that our current theories have some serious shortcomings to them. That's what makes this exciting. By the time this is done, well, I'm already way past my prime, but I'll be even further past my prime by that time. But I still have every intention of doing science with this telescope, every intention. But it's really, it's the people who are in college now, not even yet in graduate school,

they'll be the young whippersnappers who will turn the world upside down when they get their hands on these new facilities. Pat, thanks so much. My pleasure. Pat, or Patrick McCarthy, is the director of this project called the Giant Magellan Telescope, already taking shape in shops here in Pasadena and elsewhere around the world. Hopefully, as he said, first light and precursor to science in less than 10 years. We will check out the lights in the night sky, the current night sky, with Bruce Betts in this week's edition of What's Up in just a few moments. Standing out in front of the now official headquarters of the Planetary Society,

I don't know if it was official before the ribbon was cut today, but we've just wrapped up the Planetary Society open house, and several hundred people, I think, had a great time. Wait, I've got to go back. Was I supposed to be working from the time we moved in here? You were all day upstairs today working hard. You were demonstrating the life experiment for people. It was yeoman's work. I was impressed.

Thanks, yes. It was three, three and a half hours of straight talking, which is why I'm excited now to be doing Planetary Radio with you, Matt. What a finish. What a killer finish. He's Bruce Betts, the director of projects for the Planetary Society, and he's going to tell us about the night sky right now. Night sky, still got that craziness partying over. Hey, we'll be able to see it really soon. If we look in the west, super bright Venus being the thing to target on. And then if you look above Venus, you have Mars and Saturn kind of moving back and forth with each other, doing a little

dance. You can also check out Jupiter rising in the early to mid-evening in the east. So spin your head on that swivel and go to the other side of the sky, and the super bright object there will be Jupiter. High overhead in the middle of the night. Perseid meteor shower peaking around the 12th, 13th. And you can check it out for a few days before, a few days after. One of the best showers of the year. Go out, stare up, look at the sky, watch the little streaks of light going across the sky.

We move on to this week in space history. We had a couple of big launches, one of them five years ago. Mars Reconnaissance Orbiter doing great still, taking data at Mars. And a little bit longer ago, amazingly to me, 20 years ago, Magellan, not a launch, but Magellan first went into orbit around Venus. On to random space fact. You are beat. And it's too bad because there were some people who wanted to do random space fact, but they had to take off. So I think we're closing the

place down. Fairly well known one, but then we move on to something a little more obscure. The Earth is spinning and doing that precession thing. always likened to a top, top precessing. So right now the North Pole points at Polaris, but other times it doesn't. But here's the little bit more obscure thing. Apparently, back in the time of ancient Greeks, the mid-northern latitudes, like ancient Greece, could actually check out the Southern Cross. But because of the precession since then, hey, not so much. So enjoy it for us down in those southern latitudes. So someday it's going to be the Central Cross again. I don't think it'll go

that far. Alright, let's go on to the trivia contest. Okay, we asked you, in what I thought and had hoped would be a pretty straightforward thing, how many solar arrays does the International Space Station have attached to its truss? How did we do, Matt? Now, this time, I am convinced you were not making any attempt to be devious or tricky, but people did get somewhat confused because there are different ways to define this, but NASA says that there are 16 arrays. Now, we know that, in fact, because we have a

wonderful image of it against the surface of the sun, and there quite visible are all 16 of these, and we'll thank Peter Carr for sending this to us. So 16 solar arrays, and our winner, by the way, is Joe Hardy. First time winner from Centerline, Michigan, and he has won himself a Planetary Radio t-shirt. We also learned that it generates 110 kilowatts, a lot of power. That's enough, we were told, by Ian Jackson to run 20 Hubble Space Telescopes.

Or one hairdryer. Is that why the lights dim in your neighborhood? Hey, with this long hair, I've got to work hard on getting it dry. It's worth every moment. I do have good hair, don't I? Anyway, we move on to the next trivia contest. And in celebration of the funky solar things that have been going on lately, solar storms and such, what are the three parts of a typical coronal mass ejection, or CME? It's a little tricky, and I'm just going to say it up front.

Therefore, it's not tricky anymore. Not all CMEs have all three parts. But a typical one has three parts. What are they? The id, the ego, and the superego? God, now I've come up with a new question. Nice. You have until the 16th of August, Monday, August 16th at 2 p.m. Pacific time,

to get us this answer, and let's give away that other great pair of Celestron astronomical binoculars. Get out of town. We're giving away the other Celestron astronomical binoculars. Get out of town. We're giving away the other Celestron astronomical binoculars? They're gathering dust. They're sitting there in the office. I think we ought to put them out in the hands of some people who will appreciate them. I thought you said I could have them. I never said that.

Okay, let's give them away. So go to planetary.org slash radio, find out how to enter. All right, everybody, go out there, look up at the night sky, and think about those little annoying bugs that fly around your face. Thank you, and good night. They have been bugging me for hours out here, and I'm going to go home where we don't have them anymore. He's Bruce Betts, the director of projects for the Planetary Society.

He joins us every week here for What's Up. Author Mary Roach has just written Packing for Mars. We'll talk with her 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! Thank you.