Planetary Radio: Space Exploration, Astronomy and Science - Listening for the Big Bang With LISA

Episode Date: October 18, 2010

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Music Listening for the birth of the universe and more, this week on Planetary Radio. Music Welcome to Public Radio's travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. Could the gravity waves generated by the Big Bang still be detectable? The men and women of LISA hope so. LISA, that's the Laser Interferometer Space Antenna, an antenna that will listen not for electromagnetic waves, but waves of gravity,

and will do so with some of the most amazing instrumentation ever created. We'll talk with Tom Prince, the U.S. chair of the LISA science team that hopes to one day put three spacecraft in deep space and connect them across millions of kilometers with laser beams. Emily Lakdawalla will take us back to the American Astronomical Society's Division for Planetary Sciences meeting held in Pasadena a couple of weeks ago, and Bruce Batts will help me decode this week's listener introduction of Random Space Fact.

Bruce also has some great tips about what to look for in the night sky. Wonders of the Solar System is the terrific BBC series presented by Professor Brian Cox. We're giving the three DVD set to the winner of the new space trivia contest. Bill Nye will return with his commentary next week. The science and planetary guy got a last-minute summons to Washington, D.C. for the White House Science Fair. Emily, thanks for checking in with us on the road. This will be a somewhat abbreviated report. for the White House Science Fair. Emily, thanks for checking in with us on the road. This will be a somewhat abbreviated report.

We'll hear more from you next week, and I think we're going to hear more about DPS both this week and next week. What did you want to cover today that you saw at that recent conference? Well, today I thought I'd talk about the Titan stuff that I saw on the Friday morning, really right after I talked with you for the recording for last week. There were Titan sessions throughout the meeting. Titan is, of course, Saturn's largest moon. It's the second largest moon in the solar system after Ganymede. And it's the only one with a thick atmosphere. And that thick atmosphere makes Titan devilishly hard to study. So that even after Cassini has been there for, what, it's more than six years now,

I think that the state of Titan science is still kind of youthful. There's still a lot of big questions in the air about what's exactly going on on the surface. The six years that it's been there certainly has revealed much more of that moon than we've ever been able to discover from Earth. Well, that's right. And we've got lots and lots of features that are named on the surface, although I think it's telling that there's only a couple that we are really sure are craters, and the rest of them are named such and such a macula or such and such a facula,

and those two terms mean bright spot and dark spot, respectively. Or I may have those switched. But anyway, the point is that they're not really sure what they are, but they've got to give them names if they're going to talk about them. And several of the talks in the session had to do with, are these things cryovolcanoes? Are they signs of ancient fluid flow across the surface? What even was the fluid flowing across the surface? So it's been kind of interesting to watch. I saw one guy give a talk who had, in a past DPS, presented on how all of these round lake-filled features in the north were possible ancient calderas,

places where there had been volcanism and sapping underground and the surface had collapsed into these volcanic pits. And now he's talking about, well, you know, it's not so clear anymore that these are volcanic features. Fascinating. We'll have much more from Emily and other folks looking back to our coverage of DPS last week. That'll be on next week's show.

Emily, for now, we'll let you finish up your trip, and we'll talk to you in a week. All right. Thanks, Matt. Emily Lakdawalla is the Science and Technology Coordinator for the Planetary Society and a contributing editor to Sky and Telescope magazine. The most amazing thing about the proposed LISA mission is that human beings can even consider attempting something so ambitious. That's the conclusion I was left with after reading about the Laser Interferometer Space Antenna. You were about to hear Tom Prince describe it as a sort of radio receiver for gravity. Tom is a professor of physics at the California Institute of Technology in Pasadena,

California. That's where he directs the Keck Institute for Space Studies. He is also a senior research scientist at the nearby Jet Propulsion Lab. Most significantly for our topic today, Propulsion Lab. Most significantly for our topic today, he is the United States Chair of the LISA Science Team. Tom and his LISA colleagues recently got good news from the National Research Council. The NRC's ASTRO 2010 decadal study recommended that NASA make LISA one of its next major missions in cooperation with the European Space Agency. Very significant technical challenges are still ahead, even if LISA receives full funding. But the opportunity for groundbreaking science makes a compelling case. Tom, thanks so much for welcoming Planetary Radio into your office here at the Cahill Center, a building I love to visit at Caltech.

Yeah, it's an exciting building architecturally. Yeah. We enjoy living here. And you have a nice view too. And among other things, among other projects, a project that is jaw dropping. I was on the website yesterday exploring the LISA mission, the proposed LISA mission. And I kept mouthing expletives because I could not believe, first of all, how ambitious this mission is, how it will look back to, as we were just talking about before we started recording, far less than a second, perhaps. Perhaps, yes. Perhaps, after the initial inflation known to so many of us as the Big Bang.

Yes. LISA probes – well, first of all, LISA looks at gravitational waves. Okay, so these are the distortions in space that was predicted by Einstein's theory of general relativity. And so possibly way back in the early universe, there were such large chaotic mass motions that gravitational waves were generated.

Now, those were generated when the universe was incredibly tiny. But now, just like everything else in the early universe, they've been redshifted and expanded. And we'll now see them actually on kilometer scales, okay, or millions of kilometer scales with LISA. Now, we're not guaranteed of seeing that radiation, but we'll certainly be looking for it. And looking for much more immediate, much more contemporary events as well from black holes? Yes. Black holes are our bread and butter on LISA. It's been found that over the last, say, roughly 10 to 15 years, that every galaxy that we look at that has a bulge in it, and that's just about every galaxy has a bulge in it, you know that from

looking at pictures of galaxies, that within that bulge is harbored a massive black hole. We also know that as you look back in time, that galaxies merged. It's almost unescapable that when the galaxies merged, their black holes merged. Okay, so what LISA will look for then is the merging of massive black holes. And these are very massive black holes. These are black holes that are as massive as a million times the mass of our own sun.

For instance, in our own galactic center, there's a black hole which is roughly four million times the mass of our own sun. For instance, in our own galactic center, there's a black hole which is roughly four million times the mass of the sun. The interesting thing about these mergers when they happen, and here's a little factoid, is that when those black holes are merging right at the end, they are at that time giving off a thousand times more energy than the whole rest of the universe combined electromagnetically. Okay, so if you add up all the light and all the x-rays and all the ultraviolet light,

add it all up, multiply it by a thousand, that's how much energy is being given off in this last merger. What is essentially happening is that a million solar masses of energy, rest energy, is being annihilated in a very short amount of time. Absolutely incredible. And these waves, you talked about them being redshifted, just like the cosmic background radiation, the microwave radiation. Yes, right. Essentially, the shift in frequencies just because of that. Yes, yes. And if you go back to the time scales of Wilby programming,

which is 10 to the minus 20 seconds or earlier after the Big Bang, the initial event, we are talking about particle size, elementary particle size scales that are now being redshifted to essentially millions of kilometer-type scales that we'll be looking at with LISA. In fact, you're looking at a much lower frequency range than some of the other work that is

taking place looking for gravitational waves. I think the most well-known gravitational waves experiments are the ones that take place here on Earth. are the ones that take place here on Earth. There's the LIGO experiment, which there are sites in Hanford, Washington, and in Louisiana. They're actually on somewhat shorter scales, those facilities. They have laser interferometers in them with arms that are about 5 kilometers long.

Our arms are 5 million kilometers long. So we're roughly probing link scales that are roughly a million times larger, roughly five kilometers versus five million kilometers, and correspondingly frequencies, which are sort of periods that are a million times longer. The science that you were talking about is no more amazing than the technology behind this mission.

Yes, the technology is quite amazing. And everybody should go and take a look at the video that we'll put a link up to from the show page at planetary.org, which is wordless and doesn't need any words really, although you told me it may get some. Three spacecraft, five million kilometers apart, gold platinum cubes floating freely inside these, micro thrusters holding them perfectly, and I mean perfectly, in place. Nothing's perfect. Okay. But this is just, I mean, really, has anyone ever attempted something like this? So nothing quite like this. But let's go back to the ground-based gravitational wave observatories, which are operating right now.

Right now, those observatories are doing a measurement of distance, which is accurate to one part in 10 to 21. One part in, you've got to repeat that, one part in 10 to the 21. One part in, you got to repeat that, one part in 10 to the 21. Right. And let me give you just a feeling, well, not a feeling for it, but an analogy. If we were to measure the distance to the nearest star to the width of a human hair, that would be about one part in 10 to the 21. Okay. And so you say, has anybody ever done this? Yes, those gravitational wave observatories on Earth are doing that every day when they're running. So they're measuring that kind of accuracy. Our conversation with Tom Prince of the LISA mission will continue after a break.

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That's planetary.org slash radio. The Planetary Society, exploring new worlds. Welcome back to Planetary Radio. I'm Matt Kaplan. Welcome back to Planetary Radio. I'm Matt Kaplan. If it's funded, the LISA mission will one day allow us to explore our universe by detecting waves of gravity. The trio of amazing spacecraft will measure the distortion of space caused by the collision of black holes with a million or more times the mass of our sun. And they just might let us listen to the birth pangs of the universe. Tom Prince is the U.S. chair of the American and European LISA science team.

He just told us that the ground-based gravity wave detectors are already looking for these waves with an utterly exquisite level of sensitivity. But they can't do what you can do or LISA will do in space. That's correct. So what the advantages with Lisa is that we don't have all the seismic disturbances and the oceans and everything else that on Earth causes a lot of noise, particularly at lower frequencies. So Lisa can get up there. It's a very quiet environment. And so we can go to much, much lower frequencies than you can go on the Earth. And therefore, we can look at some of the very strong sources that are at those lower frequencies. Frequencies down to a tiny fraction of one hertz.

Right. A millihertz is sort of our scale, so a thousandth of a hertz. So what kind of a jump in sensitivity does this represent over, for example, the LIGO experiment? Well, it depends on how you talk about it. Actually, it's not so much that we're increasing the sensitivity enormously, but that we're able to go down to those frequencies at all. I see. So in the frequency bands, we have roughly comparable sensitivities in the two frequency bands. It's just that we can go all the way down to those very low frequencies. And that's where some of these very massive black holes emit. So it's like

a radio station. So we're tuning into the very, very low frequency gravitational waves. The earthbound detectors are tuning into the high frequency gravitational waves. And Lisa will be very good at picking up these very low frequency events caused by the massive black hole. I mean, is it fair to say the massive black holes, they simply have deeper voices when they glide? Indeed. They're bigger. They have deeper voices. And being bigger, they emit longer wavelengths.

So whereas, say, the LIGO ground-based observatory'll look at small black holes, maybe about 10 times the mass of the sun. And so we'll look at it about a million times the mass of the sun. That's the million difference there. No one has directly observed gravitational waves yet, but we know that they exist. We have very strong evidence that they exist, is what I would say, is that what was seen, and Hulse and Taylor won their Nobel Prize for this a while back, is they saw two neutron stars. So neutron stars are objects that are very close to being black holes, but not quite. Two neutron stars orbiting each other. And what they saw is that their orbit was actually decaying. The period was getting shorter. And the period was getting shorter at exactly the rate that you would predict if gravitational waves were being emitted from that system.

Okay. So that's our evidence. And so it would be very surprising if we saw something different about gravitational waves. saw something different about gravitational waves. Why haven't we actually seen or directly detected these waves with the existing ground-based experiments? So I have bets out that those detectors will see events. When they come up, actually within about five years, they will be making an advance of about a factor of 10 in sensitivity. I think that will make all the difference between seeing and not seeing events.

So what is the status of LISA, particularly in light of this recommendation that your team, the LISA team, has just received as part of this decadal study? Yes. So we were very gratified by the strong recommendation that we got from the recent decadal review of astronomy and astrophysics. So that certainly gives us a boost. One thing that I should point out is that this is a mission that is done jointly between Europe and the United States. So we have a very strong endorsement from the U.S. astronomy and astrophysics community. Going on right now is a review of major large missions on the European side. So we are talking daily, weekly to our European collaborators, working with them on the review on the European side. And so we

hope very much that that review goes well. And when both then Europe and the United States come out strongly for this mission, I think it'll go ahead. What is the LISA Pathfinder mission? Something that may happen much sooner. Right. So the LISA Pathfinder is definitely being constructed. The instrumentation is coming together right now. That mission is going to be launched probably in 2013. Okay, so actually a relatively short time from now. And what it does is it tests some of the primary technologies of LISA. So what LISA does is actually fairly simple in concept. It measures very accurately the positions of two masses.

These are those gold platinum cubes. These are those gold platinum cubes. These are these gold platinum cubes, one in one spacecraft and one in the other spacecraft, and measures the distance between those and the changes in distance between those very, very accurately. Well, what we've done is in some sense shortened those arms and brought it all into one spacecraft. So we're flying two of those platinum masses with an interferometer in between them, and then measuring then how much the distance between them fluctuates. And if we can then show that the fluctuations are very, very small, we can immediately say we can build the same type of environment on LISA and also have very

small fluctuations in those masses and therefore make the very sensitive measurements that we want to. So truly a pathfinder on the way to this mission, which I bounced this off of you before we started recording, that in some ways this mission struck me, at least in scientific significance, as does the LHC, the Large Hadron Collider. Am I off the mark? So this is really a frontier mission. It's doing frontier physics and astronomy. Our view of the universe so far has been all through light, through radios, through x-rays, all of what we call the electromagnetic spectrum, and a little bit through particles. We know that gravitation is just fundamental in the universe.

We know that there are many aspects of gravitational physics, fundamental gravitational physics, that we don't understand right now. And LISA will be just a tremendous mission to explore both that fundamental physics of gravitation and the astrophysics that's opened up when you view the universe in an entirely different way. Wish you the greatest of luck with this mission. And you know what? If nothing else, at least it enabled Kip Thorne to become a cartoon character. Yes, you've seen that. Very good, yes. We had fun with that one. And we will put up a link to that as well

where you can find this show at planetary.org. Just look for the show page. We always have a link up at the top left of the homepage at planetary.org. Tom Prince, thank you so much for telling us a little bit about Lisa. Yes, fun. Tom is a professor of physics

here at the California Institute of Technology, better known perhaps as Caltech. He's a senior research scientist at JPL and, most significantly for this conversation, the U.S. chair of the LISA International Science Team. We're going to check in with another person with strong ties to Caltech. That's our own Bruce Betts when we join him for this week's look at the night sky and what's up. Bruce Betts is the Director of Projects for the Planetary Society. Just happens that at the end of each episode of Planetary Radio, he joins us for What's Up, and he's at the other end of the Skype line right now. Welcome back. Here I am, just happening to join you.

It just seems to happen. I couldn't be happen-ier. Ah, ah, wow, nice happenstance. Tell us what's up. What's up is Jupiter looking really bright in the evening sky, dominating brightest star-like object over in the southeast, moving to the south and high overhead in the evening? Check it out with a small telescope or even with binoculars, as I did the other day. You hold them still enough and you can see the Galiland satellites, the large moons of Jupiter, appearing as little dots next to Jupiter. of Jupiter, appearing as little dots next to Jupiter. You can also still check out Uranus, as I also did with binoculars,

though with the city lighting, I couldn't appreciate any bluish color, but it's about two or three degrees away from Jupiter right now. There's also Comet Hartley 2. Comet Hartley 2 is in the sixth magnitude range, but it's very dispersed. So it's certainly not naked eye, or at least you'd have to have great eyes in a really dark site. But with some binoculars, you might see a little fuzz. Certainly, if you have a small telescope, you can check it out. It's moving quickly, so check out a finder chart.

It's moving significantly from one night to the next. We also have in the pre-dawn sky, low in the east, Saturn. That's it? That's not enough? Okay, there's more. No, no, I thought for sure you would say something of significance about Hartley 2. There's nothing of significance about Hartley 2 until November 4th when there's the closest encounter of the epoxy spacecraft as it flies by. Now, they're actually already taking data.

So, yes, that makes Hartley 2 all the more interesting. There will be a spacecraft flyby November 4th. I bet we'll remind people of that next week. All right, we'll try. On to this week in space history. In 1968, this week, there was the 199th and final flight of the X-15. Oh, I loved the X-15. I still like to think of it as a spacecraft.

Nothing's as cool like rocket plane. Yeah, a black needle-shaped thing that needed reaction control to fly straight when it got high enough. It was just... Dropped off the wing of a bomber. I mean, you gotta love it. Yeah, absolutely. 1905, Carl Jansky was born. Carl Jansky, for whom the unit Jansky is named, which all of you use in your everyday lives,

I'm sure, if you happen to be a radio astronomer, since it is basically a unit of flux that's convenient in radio astronomy. basically a unit of flux that's convenient in radio streaming. All right, we move on to our next segment and in our continuing quest to have people send in versions of it that rest my throat. We've got a little something different to announce it right now, don't we, Matt? We sure do. I'm just going to play it out because it's going to be obvious what Dave Altman was all about, as you hear this right now.

That from Dave Altman of Granada Hills, California. Hey, Dave, you won yourself a Planetary Radio t-shirt. We are still accepting people's personal renditions of Random Space Fact. We've got another one next week, and if you'd like to pick up a shirt, go ahead and send it to us. Just attach an MP3 to, what's that email address? Well, they can go to

planetary.org slash radio and find out all about it. Ah, good idea. Drive them to the website. That's what we want to do. What is the Random Space Fact? The random space fact, the core of the sun, it's the only part that produces an appreciable amount of heat from fusion. The rest of it's just oozing out through it. So within about a quarter of the sun's radius, you have 99% of the power being generated by fusion. Within 30% of the radius, you pretty much are done with fusion because you require those ridiculously high pressures. So we go on to the trivia contest.

We had the smallest number of entries and the smallest number of people who got it right that I think we may have ever had. Who knew? I mean, I knew it was a funky question, but what soon-to-be-launched spacecraft is named after a cookie? Or at least appears to be named after a cookie. And of the few guesses that we got, there were some pretty entertaining ones. For example, this is not what we were looking for, Steve, but Steve Kasselman of Memphis, he figured that we meant the Falcon 9, the next launch of SpaceX's Falcon 9. And there is a Falcon cookie or there was. And in fact, he sent us a photo of a Millennium Falcon cookie sitting on the rim of a glass of milk.

The other cute one that I'll mention is from John Gallant. John Gallant. John said that it's the Russian Dnepr, which is actually an anagram for R-E-P-N-D, a prototype Girl Scout cookie scheduled for release next year that stands for Reproduction of a Peanut Nougat Devil's Food. You're really stretching, John. You want to know who actually won? I do. It was Joel Tatham. Grunsboro is the town in Suffolk in the UK.

And Joel has not won, get this, in over four years. His answer, O slash Oreos, launching on a Minotaur 4 on November 20th of this year. That's the one we were looking for, Oreos. So, Joel, we're going to send you a Planetary Radio t-shirt. We probably ought to send them a little packet of Oreos as well. O slash Oreos, by the way, stands for Organism, Organic Exposure to Orbital Stresses. What else could it possibly stand for? Cookies!

I love the cookie. All right. What have you got for next time? It's time once again to play Where in the Solar System? Where in the solar system? What body, other than my basement, will you find arachnoids? Arachnoids. A-R-A-C-H-N-O-I-D-S.

Arachnoids. Where in the solar system will you find arachnoids? Go-R-A-C-H-N-O-I-D-S, Arachnoids. Where in the solar system will you find Arachnoids? Go to planetary.org slash radio. Find out how to enter. No shirt this week. For those of you who do get the entry in by the 25th, one of you, that's the 25th at 2 p.m. Pacific time, by the way, Monday the 25th, one of you, he was saying, will win Wonders of the Solar System, the BBC production presented by Professor Brian Cox. It's a three DVD set, and I hear it is absolutely excellent.

I have the DVD in my hand, and I just opened it so I can go watch it. So it'll be slightly used when you get it. But that will go to the winner of this trivia contest that we will name in a couple of weeks. All right, everybody. Go out there, look up at the night sky, and think about cotton balls. Thank you, and good night. That reminds me. I have to go paint my toenails. So he's Bruce Betts, the director of projects for the Planetary Society,

and he joins us every week here for What's Up. Next week, it's back to DPS for more conversations with the scientists who are revealing the secrets of our solar system and beyond. Planetary Radio 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. Clear skies. Thank you.