Planetary Radio: Space Exploration, Astronomy and Science - Where Did The Air Go? Bruce Jakosky on the MAVEN Mars Mission

Episode Date: December 23, 2014

Not just the air. Where is the water that was plentiful on the red planet billions of years ago? MAVEN may help answer these questions. Principal Investigator Bruce Jakosky reports on the early, exciting science data.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Music Tasting the upper atmosphere of Mars, 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. MAVEN is fully operational above the Red Planet. We'll welcome back Bruce Tukosky, principal investigator for this mission, that hopes to answer some of our questions about where the Martian atmosphere went.

Bill Nye has the week off, but Bruce Betts is here to help me give away yet another itelescope.net account worth a couple hundred bucks. Senior editor Emily Lakdawalla is just back from San Francisco and the AGU conference. Yeah, the American Geophysical Union conference is always completely overwhelming. It's more than 20,000 geologists of various kinds descending upon San Francisco every year. And so I have to go in there with kind of a laser-like focus in order not to be overwhelmed. So this year I focused on Curiosity, which had a press briefing on Tuesday, and Rosetta, which had a press briefing the following

day, followed by the very first results from that mission. But Curiosity first, they made an announcement on Tuesday that they have finally definitively detected methane in Mars's atmosphere. So it was kind of a relief, actually, that they were able to say, yes, we've detected the very low background levels at about 0.7 parts per billion, which is very low, but detectable with a special enrichment method that they can use in their tunable laser spectrometer. But then there was this weird spike. And it wasn't just a one-time spike. It was a spike lasting about two months to about 10 times that background level to seven parts per billion. And their detection is pretty solid. I talked to a lot of scientists at the meeting.

They don't doubt that the tunable laser spectrometer detected methane. I think there's a little skepticism that it necessarily came from Mars. I think there's a lot of people who are still thinking that they haven't disproven that it could have come from the rover. I think there's a lot of people who are still thinking that they haven't disproven that it could have come from the rover. But I've read the paper, and they did a pretty thorough job of trying to come up with explanations that had anything to do with the rover and eliminating them all. So I'm not sure where that leaves us, but they definitely detected this two-month spike in methane, which is pretty interesting. A further question about that. Is there the possibility that this source of methane, if it is Martian, was just highly localized, coming from some spot in the ground that Curiosity happened to be close to. They actually looked at that in

really great detail in the supplementary materials to their paper. They tried to correlate it with all different kinds of things, like was the rover sitting for a long period in one time, and maybe the RTG heated up the ground and released some methane. But no, it wasn't correlated with how long Curiosity sat at any one spot. Was it correlated with the kinds of rocks they were driving over? Maybe a certain rock type had some kind of methane stored in it. No, it wasn't correlated with rock type or with chemistry or with just about anything else they tried to correlate it with. So they didn't really see anything that local. But in order for this amount of methane to appear so quickly and disappear so quickly, it did have to be from a source that is relatively close, like if not

within Gale Crater, then close to Gale Crater. It couldn't have been around on the other side of Mars. But the jury's still out on what this means and what the source was and how it went away so fast. And I don't think we're any less confused than we were before they reported this result, but hey, they detected it. So no speculation about Martian who just happened to be passing right after dinner. Oh, there's plenty of speculation on that in the popular media, but not by any of the scientists, I can assure you. All right, let's move on and get serious again with Rosetta out at the comet. What was revealed? Well, they showed, for the first time I saw, a lot of really fantastic close-up Osiris images.

Osiris is their science camera. And they're keeping their images pretty close to the vest. So the only people who've seen them are the team and people at conferences. Actually, not even other members of the Rosetta team have seen most of the Osiris images. So I think the most surprising one was this photo of a cliff face that was super close up. And you expect a cliff face to look kind of striated with some boulders down it. But no, this cliff face, it looked like it was made of gumballs. The principal investigator called them dinosaur eggs. And they're about two or three meters across. And

there's this notion, are we looking at how comets were put together? Are we looking at how the whole solar system was put together in these dinosaur eggs in this cliff face in this comet, this chilly remainder from the formation of the solar system? Maybe, but no other scientists can look at the pictures yet because they haven't received them. They haven't released them to the public. So it's going to be a while before everybody else gets a chance to look at these things and speculate. What else do you want to report on from Rosetta? The coolest images that I saw came not from the OSIRIS instrument, but from this dust experiment on the orbiter. And it collects dust on these plates,

and then it just picks up pieces of dust and puts them in a little mass spectrometer. But in order to do that, it has to take photos of the dust before it picks it up. And those photos were spectacular. They looked like little aggregates of comet fluff that just barely puffed apart as they landed on this plate. And that, too, tells us a lot about how the comets are put together. These tiny, fluffy aggregates just floating in space, just waiting to smack into a world and build it up into a bigger one. It's really the results from Rosetta are just going to be absolutely spectacular.

And I can't wait to see them come out in science papers over the next couple of years. It sure sounds like Rosetta may be doing one of the things that it was sent out there to do, which was to help us understand the origin of our entire solar system. Emily, what should people be watching for in the blog? I'm trying to get one article out on the Curiosity methane results before I completely go off the grid for Christmas. So let's hope I can do that. Happy holidays, Emily, and welcome back. Thank you, Matt.

She is the senior editor for the Planetary Society, our planetary evangelist, and a contributing editor to Sky and Telescope magazine, getting ready to rejoin her family for the upcoming holidays. I will be right back with Bruce Joukowsky, that aforementioned principal investigator for MAVEN that also had big announcements at the AGU conference. MAVEN stands for Mars Atmosphere and Volatile Evolution. Yeah, they had to strain a bit to make that acronym work, but you have to admit, it's catchy. And now the spacecraft is busy catching, observing, and analyzing atoms and ions in the topmost reaches of the Martian atmosphere. MAVEN principal investigator Bruce Joukowsky has visited with us before.

On December 15th, Bruce and several of his colleagues took the stage at the AGU conference Emily was just telling us about. I caught him via Skype a few days later. Bruce, welcome back to Planetary Radio, and congratulations on the early success of this mission, MAVEN. It seems like it's doing everything that you hoped it would, am I right? It really is. So far, everything is on track. The spacecraft is working beautifully. All the instruments are operating as intended. Really, we have the full technical capability we intended when we set out to do the mission a number of years ago. And that really means that we're on track to be able to produce the science that we promised.

I mentioned up front that there was a press conference that you led with some of your colleagues about early results from this mission. I guess the stress is on early. You're really not too far in, are you? No, we took about a month and a half to commission the spacecraft. We've really been operating in our primary mission only for about a month now. We're still learning how to operate the instruments, how to calibrate them, what the data means, and how to interpret it. Let me describe to you where we're headed. What we're trying to do is to put together a sequence of events of how the upper atmosphere operates, from energy input from the sun and the solar wind to the response of the upper atmosphere and leading to escape. That's what we really want to

try to understand. So far, we're really only starting to get a few links in that chain, or pieces of links. So we're seeing the promise of the data. We're getting a few early results, but it'll be a few months before we can really start to say what our conclusions are, what we're really seeing, how it relates to escape. Now, based on what I saw at that press conference, I applaud you for being a careful scientist, but I think you're underselling the science so far, my personal opinion. So we won't look for conclusions here. Those are still to come. But it's very promising, isn't it? It is. And what we presented at the press conference are early discoveries,

not just early observations. For example, one of the things that we've seen is a previously unexpected penetration of the solar wind deep into the upper atmosphere in a region where we didn't think it could possibly get. So that's something brand new for Mars. That was certainly one of the really great announcements. That took me by surprise, and apparently it took you guys by surprise as well, you've indicated. What does that mean for the influence of the Sun on this diminished atmosphere? Well, let me first describe the process by which the solar wind has penetrated. On the Earth, the solar wind is deflected around the planet by the presence of a magnetic field. It just can't penetrate. Mars doesn't have an intrinsic magnetic field the way the Earth does, but it has an induced magnetic field resulting from the

presence of the ionosphere, and that serves the same purpose. It causes the solar wind to deflect around it. There's no way that the charged particles of the solar wind can penetrate into the ionosphere very deeply. What we're seeing on Mars, though, is exactly that kind of penetration, where stuff very deep in the ionosphere has the same energy, the same speed as the solar wind. What we think is happening is it's exchanging charge with stuff in the ionosphere, the solar wind is, and it becomes neutral. At that point, it's no longer deflected by the solar wind and it can penetrate as deep as it wants to. It undergoes a charge exchange back to an ionized form and that's the way we detect it. So we think that

this process is going on continually as the solar wind hits and penetrates, and we're just seeing the stuff that has timed it perfectly to penetrate deeply. What this means is, first, that we can detect the properties of the solar wind at a time when we didn't think we'd be able to, when the spacecraft is deep into the ionosphere. And that's really important for understanding what the characteristics are at that time. We're also trying to understand whether there's any influence on the properties of the upper atmosphere or the ionosphere itself. And I'll have to say we're very early in that and just having the first discussions. Something else that surprised me, if I understood correctly, is that there are things going on at the surface of the planet that are affecting the upper atmosphere.

There are a couple of things. One, if you go all the way down to the surface, there are regions that are magnetized and regions that are not magnetized. These magnetized regions were discovered by Mars Global Surveyor 20 years ago. These magnetized regions locally serve that same effect to deflect the solar wind and to affect how we interact with it. But also, if you move up a little bit, the bottom of the atmosphere affects the top of the atmosphere. If you heat it up, heat up the bottom of the atmosphere, for example, with a dust storm that absorbs sunlight, it'll heat up, it'll expand, and that pushes the whole atmosphere up. With MAVEN, we're trying to target our periapsis, our lowest altitude, to a certain density where we can make our measurements. our lowest altitude to a certain density where we can make our measurements.

And we find that we have to look every week to see whether the atmosphere has moved up or down, and we need to adjust our altitude. So there's enormous dynamism in this atmosphere. And you also saw, not surprisingly, I guess, great variability in the sun's activity and its influence. That's right, and that's one of the things we're looking to see, what variations in the energy from the sun are coming in, and then how does the atmosphere respond? We're seeing changes in the extreme ultraviolet,

which affect the ionosphere, creates the ionosphere by knocking off electrons from whatever's there. We're seeing solar storms that hit the planet, coronal mass ejections, big blobs of stuff coming out of the sun. We've seen these hit the planet, but we haven't yet seen one where we can analyze the response of the upper atmosphere. That's one of the major objectives of MAVEN, to see what that input response is. That's MAVEN principal investigator Bruce Tukosky. After the break, he'll tell us about his spacecraft's close encounter with a comet. This is Planetary Radio. Hi, Emily Lakdawalla here. Thank you for listening to

Planetary Radio. The Planetary Society has lots more ways for you to hear the latest news and see the greatest pictures from around our solar system. I lead a growing family of expert bloggers at Planetary.org. We cover nearly every angle on space exploration. And you can find us all over online, tweeting, and posting to our popular Facebook and Google Plus pages. We're also producing great new videos for our YouTube channel. There's no doubt about it, we really are your place in space. Random Space Fact! YouTube channel. There's no doubt about it, would he? I really wouldn't. A new Random Space Fact video is released each Friday at youtube.com slash planetarysociety.

You can subscribe to join our growing community and you'll never miss a fact. Can I go back to my radio now? Welcome back to Planetary Radio. I'm Matt Kaplan of the Planetary Society. It was barely three months ago that MAVEN joined a flotilla of human-made robots at Mars. Arriving almost at the same time was India's MOM, or Mars Orbital Mission, but MAVEN's mission is unique, as we are hearing from Principal Investigator Bruce Tukosky. The first science data were revealed at the recent meeting of the American Geophysical Union, and Bruce is recapping them for us on today's show.

There have already been some surprises, and one of those came from yet another visitor to the Red Planet. In this amazing episode of Serendipity, perhaps especially in the case of MAVEN, we had this comet sighting spring that happened to pass by rather close to the Red Planet. You weren't really active when the comet was closest, right? That would have been dangerous. Well, the risk was that dust that had been released from the comet might hit the spacecraft. The comet and any dust connected with it were traveling at 56 kilometers per second relative to Mars and to MAVEN. So even a tiny, smaller than a millimeter size grain could create great damage, cause great damage to the spacecraft. We adjusted where we were in our orbit so that at the time of peak risk by dust, we were shielded from that dust by the planet. That was very effective.

But then as soon as the period of risk was over, we wanted to turn the instruments back on in order to see what they did at Mars, what the effect of the comet at Mars was. And through heroic efforts by Lockheed Martin, where they're operating the spacecraft, we were able to determine that it was safe and get the instruments back on within just a couple of hours after the comet close approach. And we saw some truly amazing things. We saw metal ions in the upper atmosphere. These were created from dust that hit the upper atmosphere. It's not that the dust is metal, it's usual rock-like materials. But at the speed it hits the atmosphere, it vaporizes and ionizes. So it leaves everything in an ionized form.

And we detect the metals because they're easiest to see. So we saw a brand new layer in the ionosphere created by these metal ions. Other spacecraft saw the electrons that were kicked off in the ionization process. So we're seeing a very consistent picture of a dynamic upper atmosphere in response to the comet. We were able also to use that to estimate how much water and how much dust might have hit the planet and what it would have looked like to somebody standing on the surface. If you were there and seeing this at night, you would see thousands to tens of thousands of meteors streaking through the sky per hour. That would be a tremendous storm. Wouldn't that have been spectacular to stand on that surface and watch?

Bruce, everything that you have talked about is great evidence of the truly amazing array of instruments you have on this spacecraft. Could you just take a minute to remind our audience of the kinds of capabilities you have? I'll start with what we don't have. We don't have traditional imaging instruments designed to look at the geology of the surface. We're a mission devoted to studying the upper atmosphere and how it interacts with the sun. We want to make the measurements of what is the solar input, the input from the solar wind. So we have a suite of measurements designed to measure the solar properties and the solar wind. And then we want to see the response of the upper atmosphere. And we've got a couple of instruments that look at composition and structure, one using

remote sensing and one in situ at the location of the spacecraft. And then we want to see how all of this leads to escape. So we've got a couple of different instruments that are able to look at atoms or ions that are escaping. So hopefully we're going to be able to put together this whole chain of events from energy input to escape. By doing that, we can understand the processes driving the escape, and that allows us to extrapolate backwards in time and to infer the total loss of the atmosphere to space through time. That's really what we're at.

We're trying to understand the role that loss to space, interaction with the sun, played in the history of the atmosphere, the history of the climate. How much longer do you hope that MAVEN will be delivering this data back to Earth? Well, we were approved for a nominal primary mission of one Earth year.

That means that's what we proposed, and we think we can make major progress in answering our science questions in a year. But since we went so cleanly into orbit and didn't have to use any of our fuel to recover from possible problems, we have a lot of excess fuel that we can use for an extended mission. We have the ability, we think, to last for up to 10 years. And that would be spectacular. We could get observations through a full solar cycle and really understand

how the variability of the sun plays into this. We have heard time and time again about the benefits of these extended missions for so many other spacecraft and missions around the solar system. Sounds like the same promise is there for you folks,

and so I certainly hope that this is something that you'll be able to continue for many years to come. I got one more question, which if I don't ask, I know I'm going to get mail. With that discovery, the announcement of the finding of methane, by curiosity, down on the surface, at least localized methane, does this mean anything at all for you folks keeping an eye on the surface, at least localized methane. Does this mean anything at all for you folks keeping an eye on the upper atmosphere? Well, unfortunately, we don't have the ability to detect methane in any form at all. The measurements don't connect up. Methane is a trace gas in the lower atmosphere. It's very important for understanding biological and geological

processes today, but we don't think it's important for the long-term evolution of the atmosphere, and it's nothing that we'll be looking at with MAVEN. So the results that MSL are getting and what we'll be getting are very complementary to each other, studying different aspects of the same system, though. And I'm willing to bet that just speaking as an individual, as a would-be Martian, you were pretty excited about those results, the finding of methane, and everything else that we're learning about this planet. Absolutely. One of the exciting things about Mars is that we're discovering it's a very complicated system. You can't study the atmosphere in

isolation from the upper atmosphere or the surface in isolation from the deep interior. We really need to understand all the different components of Mars as a system the way we do Earth. And with the spacecraft we've sent over the last several decades and the ones we have planned for the future, that's what we're doing. ones we have planned for the future. That's what we're doing. And MAVEN fills a gap in our understanding of Mars as a system, and one that we think has the potential to be pretty important to fill in. Bruce, once again, congratulations. And thank you once again for joining us on Planetary Radio. Best wishes for much more great data and perhaps some exciting conclusions to be drawn from that data in the not too distant future. Thank you. MAVEN Principal Investigator Bruce Joukowsky is a professor of geological sciences at the University of Colorado Boulder,

where he is also Associate Director for Science at the Laboratory for Atmospheric and Space physics. Time for not the last, but the penultimate What's Up segment for 2014. So we have Bruce Betts on the line to talk to us about what's up in the night sky. Welcome back. Thank you. It's good to join you for the penultimate, the second to last show. For the ultimate pen. The ultimate pen.

The space pen, I guess. Yeah, exactly. It writes upside down. Well, not looking down, looking up, looking upside up. What's up there? Well, in the early evening, if you look actually upside down up near the western horizon, low, shortly after sunset, you may start to pick out Venus. If you miss it, it'll be up for a few months much higher soon. Looking super bright. Mars up and setting around 8 p.m. over in the west. You can check it out with the crescent moon near it on the 24th and 25th. Jupiter coming up around 9 p.m. looking super bright in

the east and Saturn in the pre-dawn east. It is a party. Yeah, sounds like a glorious sky. On to this week in space history. It was 35 years ago that there was the first launch of an Ariane rocket by the European Space Agency. Ariane rockets, of course, have evolved since then and doing all sorts of launches. On to random space fact. I have nothing to add. That was lovely. Well, thank you. The rings of Saturn, they are extremely thin compared to their diameter.

I keep searching for ways to express this, so I've come up with an analogy for you. I know you enjoy those. I really do. If the main rings of Saturn, the A through D rings for those playing the home game, the main rings of Saturn had an average thickness of a DVD. That DVD would have a diameter of over 33 kilometers or 21 miles. Oh, that's great. That's really great.

They are really, really thin compared to how broad they are. That, I believe, is one of my favorite random space facts about our solar system. That is just so surreal. Well, good. I feel an accomplishment for this penultimate show. All right, on to the trivia contest. And I asked you, what ship recovered the Orion capsule from its December 2014 first launch? And I hear we did quite well with entries. Biggest response from listeners we have had in quite a long time, probably years.

I won't say the biggest ever because I didn't keep track, but it's huge. And either they just love us to death or they... Why do these have to be mutually exclusive? Okay. And they wanted that 200-point account from itelescope.net, which we're going to give another one away of today. itelescope.net with their worldwide network of telescopes, Northern and Southern Hemisphere. The account is valued at $200 U.S., 200-point account. The winner of that account this time around, first time winner, Sidney Halliman. Sidney Halliman of McGaheyville, Virginia.

I almost certainly have that wrong. So forgive me. Forgive me. I'm a Virginian once removed. My father was a native. He was able to answer this question because of a lively discussion about the Orion launch today in his junior high school class. He doesn't mention whether he's the teacher or a student, but he says that the name of the ship was, is the USS Anchorage. That is indeed correct. Excellent. Okay. Well, Sidney,

congratulations to you. We will get that account out to you. It'll come directly from itelescope.net. I just want one other that I want to mention. Ilya Schwartz, regular listener, he pointed out this interesting parallel in the history of space. This mission design corresponds to the Apollo 4 mission of 1967, which validated Apollo flight control systems and the heat shield at re-entry conditions. A real interesting tie into the past there. Indeed it is. They had slightly different orbital parameters, but the basic gist of it was indeed validating similar types of systems. All right, let's give somebody else a chance to win that account from itelescope.net. Of spacecraft that have visited at least one giant planet, meaning Jupiter, Saturn, Uranus, or Neptune, which spacecraft had the highest dry mass?

In other words, the highest mass without counting the fuel or oxidizer. Go to planetary.org slash radio contest. Get us your entry. Would the answer be the same for wet mass with the load of fuel? Yes. As long as you compare wet mass to wet mass or dry mass to dry mass, the answer is the same. Just didn't want people to accidentally compare a wet mass of one spacecraft to a dry mass of another because then it gets screwy.

Thank you for that clarification. You have until December 30th. That's the penultimate day of 2014. December 30th at 8 a.m. Pacific time to get us this answer. It does bring about a point that these spacecraft carry a heck of a lot of fuel compared to the mass of their hardware, hence the confusion. And when you get all that fuel, it's called a wet mass. It's all moist. Sounds like something that needs to be cleaned up. We almost had a respectable show. But it was perfect for penultimate. Alright everybody, go out there, look up in the night sky and think about your favorite

font. Thank you and good night. Cambria. It's not just a font, it's an adventure on the central California coast. He's Bruce Betts, the Director of Science and Technology for the Planetary Society, who joins us every week here for What's Up. Snohomish.

Join us next week as we look back at 2014's space milestones. For many of you, this is the last episode of our show that you'll hear before the new year. Thank you for making us your place in space. I hope you'll stick around for 2015. It's going to be a big year for our solar system and beyond, and the trip wouldn't be the same without you. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by those Maven members of the Society. Clear skies. Music Music Music

Music