Planetary Radio: Space Exploration, Astronomy and Science - A Cassini Saturn Update From Linda Spilker

Episode Date: October 24, 2011

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A Cassini mission update from Saturn, this week on Planetary Radio. Welcome to the travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. The Cassini project scientist Linda Spilker returns with the latest news from our only spacecraft at Saturn. It's healthy and still doing marvelous science, but will budget cuts take it down after 14 years in space? Lots more for you on today's episode, beginning with the Planetary Society blogger, Emily Lakdawalla. Emily, several things to talk about this week, including apparently your premier performance as part of ANOVA,

but we'll get to that in a moment. How about, first of all, the image of the week? What are you going to pick from Cassini? Well, I think that my favorite one that I put together this week was from the flyby that Cassini did of Enceladus on October 1st. As Cassini gets close to Enceladus, Enceladus goes into Saturn's shadow. So it goes into eclipse, which makes it tough to take photos, but it's great for taking heat readings. Then as Cassini recedes from Enceladus, Enceladus leaves Saturn's

shadow. And so you get to see it come out of eclipse and kind of have a strange kind of sunrise as the sun is going through the uppermost levels of Saturn's atmosphere and getting a little bit brighter and a little bit brighter than pop you see in solidus. But this one was particularly cool because Titan is distant in the background. Let's go a little bit closer to home. Apparently you're impressed with the things that Japanese engineers are still managing to do with their solar sail. Those guys are so creative. And you know, for once, it's a spacecraft that's operating perfectly. So they're actually doing things that might break it, which is kind of the reverse of what usually happens with Japanese missions. But this is IKAROS. It's their solar sail demonstration mission.

It's an interesting one where its sails were deployed and are stabilized by centrifugal force. The spacecraft has to rotate to keep the sails flat and maneuverable. They actually shifted the direction of rotation. They spun it down. It had to pass through a moment where it was not spinning at all and then spin it back up in the opposite direction. When you think about the fact that the whole spacecraft is stabilized by centrifugal force, stopping your spinning just sounds like a really crazy thing to do. And yet they managed to pull it off and the spacecraft is still operating well. Unfortunately, it doesn't have long because it's almost out of maneuvering fuel and it does need maneuvering fuel in order to be able to

keep its spin stabilized. So we're probably going to be hearing the last of Icarus in a few weeks or a couple months. We got to get to this Nova. I don't know how many people saw it. I'm going to talk with Bruce about it too. Very beautiful animations, I think, were the real stars of Finding Life Beyond Earth. This two-hour Nova, which was quite spectacular and quite a roster of all-star planetary scientists as well. But you're represented in there, too. Yeah. I, in fact, produced a few of the animations of Cassini images that they used in the second hour of the program. And if you watch the closing credits go by super fast on these things, but I understand that I and the Planetary Society am mentioned in the closing credits.

I think it's going to be up on the NOVA website if you missed it on PBS. It's well worth watching. Thank you, Matt. Emily Lakdawalla, budding starlet, is the science and technology coordinator for the Planetary Society and a contributing editor to Sky and Telescope magazine. Up next, the executive director of the Planetary Society, the planetary guy, Bill Nye. Bill, you apparently beat me to New Mexico by about a week. What were you doing there? I was invited to the Air Force Research Lab at Kirtland Air Force Base in Albuquerque, New Mexico in the U.S.

And I saw the laboratory, the shop, where they formed the booms, as we say on a sailboat that hold up the sails, the booms for our solar sail spacecraft. And I met Jeremy, the extraordinary young engineer who has ways to store strain energy in these spacecraft deployment systems. And it's quite elegant. I mean, the solar sail boom fits in a very, very small package. And it deploys very smoothly. And this is where they do this work. Great.

And you saw some other cool stuff there. Oh, man. I stood in the directed energy beam for a denial, area denial system. So this beam of three millimeter wavelength energy hits you and it feels like certain areas of your skin, like these unpredictable patches feel like they're on fire. And you just jump out of the beam. I mean, you can't stand in the beam for a second and a half and you just jump out of there. And yes, I was there with the director of the Directed Energy Directorate and he could not stand in the beam either. Nobody can. Do they call him Triple D? I didn't hear that. They call him Doctor.

I see. Oh, it's Quadruple D. I see. Yeah, yeah. Now it'd be, yes, Quadruple D. The doctor director of the directed energy director. At any rate, that was exciting. It was good to see how these extraordinarily lightweight and stiff booms were made for our spacecraft. I saw a laser that's just chlorine and iodine, and it's so hot. How hot is it? It can burn through metal. Remarkable what they do with directed energy.

Now, with all that said, this week, Matt, I will be in Boulder, Colorado in the U.S. at the Students for Exploration and Development of Space, the SEDS conference. I'm very much looking forward to that. We really want to engage young people at the Planetary Society so we can get more young people involved in the extraordinary time in which we are living, which we are exploring the planets. We're discovering planets around other stars and we want young people to be a part of it. Space brings out the best in us, Matt. It's just a great week. And thanks for joining us once again on Planetary Radio. Thank you, Matt. He is the executive director of the Planetary Society, the science and planetary guy. Join us at Saturn in just a few moments.

No one has been our guest more often than Linda Spilker, the project scientist for the Cassini mission, still exploring Saturn, its moons, and its beautiful rings. Last March, NASA's highly respected Outer Planets Assessment Group saluted Cassini and its ongoing accomplishments. I did the same in a recent phone conversation with Linda. She spoke to me from her office at the Jet Propulsion Lab. Linda, it is always great to get you back on the show, especially on the 14th anniversary of the launch of your spacecraft. Congratulations. Well, thank you, Matt. I'm very happy to be here.

Just incredible that this spacecraft has done and continues to do the magic that it is out there in the Saturnian system. Tell us, first of all, what's the health of the spacecraft? The spacecraft is in good health. We have one of the instruments right now that's turned off. It's the CAPS instrument, the Cassini Plasma Spectrometer. And we turned it off in June. It turns out that we were seeing some problems with the voltages, and we think that perhaps there's a capacitor inside the CAPS instrument that might have shorted out. So to be on the safe side, we turned it off. We're going to study the problem before we resume CAPS operations.

But the other 11 instruments and the spacecraft itself are in good health. Absolutely incredible performance. We always talk, of course, about how well the Mars Exploration Rovers, or now Rover, have done over their history on Mars. I think it is easily equaled by this mission into much deeper space. There's much more to talk about. Let's start with that big storm that's, I guess, now petered out. Oh, it's just an incredible storm. Call it a jaw-dropping showstopper, if you will. We first saw this storm on December 5th. Just luckily saw one of the Cassini images,

and it was great because the amateurs jumped on board, and they've really been useful in helping us, fundamental really, in helping us monitor this storm because Cassini isn't always looking at Saturn. It's a huge storm. It's 500 times larger than any other storm that Cassini has seen on Saturn. It's the first storm in the northern hemisphere that we're really seeing the seasons change. It's now spring in the northern hemisphere. And this storm literally erupted, went completely around the planet. And so the tail of the storm wrapped back around with the head. And it appears now to be slowly fading with time. And we saw incredible amounts of lightning, something like 10 flashes per second, coming from clouds in this storm region.

So it's really a monster storm. Not only saw this lightning, but heard it as well, at least once it was converted to acoustic information. Here's just a sample of that. acoustic information. Here's just a sample of that. And we love these opportunities to let the solar system talk to us on this radio show. So thank you. Please thank your colleagues for that, Linda. Let's move out to Enceladus. You just had a flyby 99 kilometers above the surface on October 1 and got another one coming up? That's right. The October 1 flyby was a very close flyby.

In particular, our ion and neutral mass spectrometer was able to get in there and actually pace the jets themselves. And it was really a neat flyby. We lined up the spacecraft to literally fly along one of these giant tiger stripe-like cracks on Enceladus and measure the varying jets and productivity along the plume itself. And this is one of a series of three flybys where we're going to overfly in a very similar kind of orbit this similar tiger stripe. Let's talk about the rings back down to the planet now. I mean Enceladus has this close relationship with the ring system as well. I bring it up in particular because my colleague, Emily Lakdawalla, who you know well,

asked me to ask you about the compact infrared spectrometer because she was very curious about what it's been able to tell us over the years of the mission about the ring particles. Right. Well, that's the instrument I actually work with and work with the ring science team, and it turns out we've been monitoring with the Composite Infrared Spectrometer, or SEERS as we call it for short, the temperature of the ring starting early in the mission where the sun was high up over the rings

through equinox where the sun was edge-on, and it's been fascinating to watch the evolution of those temperatures. And basically when the sun was edge-ged onto the rings at Equinox, the rings cooled to the coldest temperatures we've yet measured to date. And so cold that it's like the sun had been turned off, and the only heat source left was the planet itself. And so we got a chance to see what the rings look like with just Saturn providing the heating. And we could tell that because when we looked at the rings in the shadow of Saturn,

they had the same temperature as when they came out of the shadow and would be what we'd call on the noon side of the ring. So it was just a fascinating time, and we're learning more by these studies of if you could take a ring particle and hold it in your hand, you know, what would it look like? Would it be a fluffy snowball, a hard-packed ice ball, or maybe something in between? And so this is a really good way to get at some of the physical characteristics of the ring particles. Yeah, Emily is obviously very anxious to hear about these continuing observations as basically, what, the north face of the rings heads into summer? Right, right.

Yes, the sun moved from the south face of the rings to the north face and will continue to move higher. And in fact, the goal of the solstice mission is to go out to 2017, which is Saturn solstice or Saturn northern summer, and to observe Saturn for another entire season. What's another six years after 14 years in space? Oh, right, right. More from Linda Spilker of the Cassini mission in a minute.

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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. Our guest, as she has been many times before, is Linda Spilker, project scientist for Cassini at Saturn. While she oversees all science activity for the mission, Linda's own work focuses on the great planet's beautiful and still somewhat mysterious rings. While we're talking about the rings, I got to bring up an image that is certainly a favorite of my boss, the science guy, Bill Nye. He uses it in, I think, all of his presentations around the country. And that is,

it's a beautiful shot of the planet and the rings. But then he pops up a little arrow that has this, if you'll pardon the expression, pale blue dot. Yes, it's one of my very favorite images. And it's something only a spacecraft could get an image of. What it is, is a series of pictures taken by the cameras where the sun is covered up by Saturn. And so what that allows you to do is to see anything in the system, any dusty, tiny particles, suddenly become very bright. If you've ever had a dusty windshield and you drive toward the sun, you'll notice it suddenly gets very hard to see as those tiny, dusty particles light up and send photons into your eyes.

In the same way, we captured this image. And usually we can't get a picture of the Earth with Cassini because the Earth is just too close to the sun and would damage the cameras and other instruments. But with Saturn working as a fantastic sun shield, it gave us the opportunity to capture not only the Saturn system with all of its rings visible, including the E ring, G ring, and the main rings, but as you said, we saw this pale blue dot, which is the Earth. And if you look at it closely, you'll notice it's not quite perfectly spherical,

but it has like a little lump off on one side. We're actually seeing the Earth plus the Moon in that particular image. A family photo from... A family portrait, yes. From the orbit of Saturn. It would be a stunningly gorgeous image, even without that added attraction, but it's nice to see a bit of home there hiding out. Oh, absolutely.

Do you have anything that you want to add about Titan? I mean, your spacecraft has certainly revealed far more about that big moon than we ever knew before. You know, what we're interested in seeing now as the seasons change and the sun is now going up into the northern hemisphere, we're really curious to see what might be happening with those lakes. With the radar instrument, we discovered a large number of lakes, one of them actually a large sea. And so as the seasons change, do these lakes start to evaporate? Does the liquid methane perhaps migrate to the South Pole where it's colder and is now

becoming winter, fall then winter? So what's going to be happening with those lakes on Titan? And of course, with the radar instrument, we continue to map out sections of Titan. We haven't yet seen in detail with the radar, as well as just continue to study and better understand Titan as a whole. You know, here's a moon with a thick, dense atmosphere, mostly nitrogen, but with methane and other organic compounds, kind of a prebiotic Earth. And as we gather more data, especially as the seasons change, we're starting to get a better understanding of this very unique world. Certainly these lakes and the other revelations about Titan,

about which we knew so little prior to Cassini, are going to be one of the lasting great achievements of this mission. What else is ahead? And then I hope you can also say something about just the outlook for the mission itself. I mean, we are in very tough budget times across the federal government. That's right. Well, Cassini right now is in a series of equatorial orbits, and that gives us a chance to have additional Enceladus flybys coming up in the next few months. It's also, if you're a Saturn scientist, a good time to study the planet because, as a Saturn scientist might say, those pesky rings are out of the way.

And you can get measurements of the full disk of Saturn. That wouldn't be you saying that, though. No, no, it wouldn't be me. But that's what the Saturn scientists might say. And in particular, we've seen a couple of small flare-ups in the latitude of the storm. There's been a little bit more lightning detected, a little bit more of the storm. And so it'll be interesting to keep watching and see if perhaps we see another storm, perhaps at the same latitude, perhaps in a different region of the planet. So are you getting hit by all the red ink in D.C.?

NASA's Planetary Science Division recently provided Cassini with some new budget guidelines that actually represent significant cuts to our solstice mission budget. And this is unfortunate because the Cassini budget was cut by one-third already in the last two years for the solstice extended mission. And now we're being asked to cut our budget again, and in one case the requested cut is actually more than we've already cut previously. And we had really cut back to what we thought was the minimum to do a successful mission. And it's tough for me personally because here we have a healthy flagship spacecraft with 11 of 12 instruments operating, taking great synergistic science on Enceladus and Titan and Saturn.

And now we're being asked to throttle back the science that we collect and analyze. But to put this in context, the Planetary Science Division has received a $1 billion cut over five years in their budget. And so they have some tough choices to make. Does the Planetary Science Division continue to fund active, healthy flying missions like Cassini? Or do they have to delay the start of new missions? Or do they have to do something else? So clearly there's a number of very tough choices to make. And with a flagship mission like Cassini, it would probably be, I think, decades before we'll get back to the Saturn system with a flagship quality mission with so many instruments and so much capability. And so for me personally,

it's tough to think about having to throttle back when we're kind of at our prime. We've sort of hit our stride and really collecting good data to have to throttle back our mission. I just would like to personally thank the public for their enthusiastic support, both of NASA, the Flying Planetary Missions, and also of Cassini, and just to encourage them to continue to support and follow Cassini. Well, I don't think you'll find a more sympathetic or friendly audience than the one that listens to Planetary Radio, Linda, and I'm sure that they share my concern about what you've expressed. And of course, we do want to mention that you're speaking only for yourself, not for

JPL or Caltech or, for that matter, NASA. But I suspect that you're not the only person there or listening to this program who would be concerned about seeing this mission not continue to deliver the level of amazing science that it has given us over the past many years. Yes. Thank you so much, Linda. It is, as I said, always a pleasure, and I look forward to the next opportunity to talk. Thanks, Matt.

It's been a pleasure. Linda Spilker is the Cassini Project Scientist at the Jet Propulsion Lab. She has been with that mission for decades. And as you heard, as we talked, we were celebrating and she is celebrating. Did you say everybody's wearing their Cassini shirts today? That's right, Cassini shirts. And we've brought in, we're going to have a little party to celebrate the 14 years since launch. Well, have a great time.

Congratulations once again. I will be right back. We'll do a little celebrating of the rest of the solar system and perhaps beyond with Bruce Betts, this week's edition of What's Up. Back in Bruce Bett's office at the Planetary Society headquarters, ready to tell you about the night sky in this edition of What's Up? And give away a really cool book, The Beauty of Space. The Beauty of Space. I saw The Beauty of Space last night.

Did you watch, first of all, Hello? Hi. You didn't see any of that Nova last night. Did you watch, first of all, Hello? Hi. You didn't see any of that Nova last night, the search for life in the universe or solar system or whatever. Really cool. I mean, the animation was just beautiful. It was just full of animation.

They must have used the one of the Mars-sized body hitting the ancient Earth, the proto-Earth, like ten times because it was just so cool. It was very cool. We need to do more animation on this show. Okay. You know, I actually have done some. Have you? Yeah, let me show it to the listeners right now. Good. Okay, is this like the collision? There you go, yeah. Alright. What do you think?

It needs sound. It needs something like when they collide like this, you have to hear, boom. No, like this. It works, right? When Proto-Earth was hit by a giant egg. A giant spitwad, I think. An organic spitwad. Jupiter's out there with a giant straw, just shooting stuff.

Okay, you know the other thing it had, almost right from the beginning of the show? Chris McKay, close-up, extreme close-up of his eyes. I'm telling you, he is so dreamy. Wow. You don't know what to say. We should just end this segment now. What's up? There's no way, higher i okay we can't

so in the sky uh jupiter jupiter looking dreamy in the night sky super bright over in the east star-like object can't miss it check it out with some binoculars or a small telescope and you can see the moons as they go from one side to the other over the course of multiple nights. Also in the evening sky go find a finer chart and pull out probably a telescope maybe even oculus check out Uranus and Neptune both out there in the south southeast in the mid evening but you will need some type of device or a good imagination to see them. And we've got Mars hanging out in the pre-dawn sky high overhead coming up around midnight,

a little after midnight in the east. Let us go on to this week in space history. It was this week in 1977 that the fifth and final glide test of the Space Shuttle Enterprise occurred, dropping it off 747. It was this week in 2004 that Cassini had a flyby of Titan. Now, what is seven years later, it's still doing awesome science. How wonderful in light of our guest today, Linda Spilker. Well, yeah. Five years ago, the stereo spacecraft were launched. This, of course, confusing because the plural of spacecraft is spacecraft. There, too, in leading and trailing Earth orbit, checking out the sun in stereo.

Yo, yo, yo, yo. Also still turning out great data. Random space fact. Oh, that's good. That's great great i want to see a big dodge charger jumping over a ditch or something okay daisy have i got a space fact for you this week the uh 75 to 90 kilowatts of power for the international space station is supplied by almost an acre of solar panels. That's about 4,000 square meters for those of you in metric land.

Let's move on to the trivia contest before I get any stranger. And before we lose any other southern listeners, any more of those. Sorry about that. I apologize for my mediocre southern accent. It's interesting that there's only one moon in the solar system that is between 2,000 and 3,000 kilometers in diameter. You've got a bunch bigger and a bunch smaller. Only one. I asked you what it was.

How did we do? Tremendous response. And you know why? It's because of the prize that we were offering to the winner of this particular contest. It's the beauty of space. This beautiful book, it's a paperback copy, Space Art from the International Association of Astronomical Artists. Our guests, what, about three weeks ago now. John Raymer.

Of course, we talked to Don Dixon on that show. There are over a hundred artists in their work in the book. About eleven artists signed their works on this copy of the book. That's very cool. And we're going to send it to Michael Bramble. Michael Bramble is our winner this week.

He's in Majorville. He says that's how it's pronounced in New Brunswick, Canada. Congratulations, Michael. We'll put this in the mail to you very soon. Got a lot of other very entertaining comments, though. I mean, people who pointed out, for example, that it was discovered in October of 1846 by Englishman William Lascelles. And do you know what he actually was? I mean, how he, I guess, found the money to do astronomy in his spare time?

Well, I do, but only because of our listeners. Me too. He was a brewer. John Gallant looked it up in great detail. He made beer. This is the kind of astronomer we need to hang out with. This is the kind of astronomer that you have to be really careful when they present their data. Georgi Petrov, he did say, yeah, you know, it really is a big weirdo. It's bigger than Pluto.

It's retrograde. Oh, yeah, it's totally retrograde. It's the only large moon in the solar system that's retrograde. We've random space fact in the past on that. Jonathan Hamill, he sent us a poem, a computer-generated poem. So it's kind of random. We don't have time to read the whole thing. But I love the last line. It does mention moons, but the last line is,

wave calmly like a small pirate. T.S. Eliot, watch out. All right, Matt. I had planned for a trivia question this week to ask people how many people named Matt had flown in space. Seriously? Yeah, seriously.

Seriously, none. Yeah, I could have told you that. Now, I can't guarantee middle names, but at least first names. No one named Matt. So I went to the next best thing. Name the people named Bruce who have flown in space. Okay.

Go to planetary.org slash radio. Tell us who named Bruce flew in space. This is actually physically flying in space, not just thinking about it. You have until the 31st, Halloween, October 31st at 2 p.m. Pacific time to get us this answer and you might win yourself a Planetary Radio t-shirt. Alright everybody, go out there, look up at the night sky and think about shirts covered in grid patterns that make your eyes hurt. Thank you. Good night. What do you mean? Look at this pattern.

This is my Enterprise... I am. This is my Enterprise holodeck shirt. Gosh, I don't want to see things appearing on your chest. He's Bruce Betts, the Director of Projects for the Planetary Society. He joins us every week

here for What's Up. Discovery of the first planet circling two stars. That's next week on Planetary Radio, which 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 the members of the Planetary Society. Clear skies. Thank you.