Planetary Radio: Space Exploration, Astronomy and Science - Water on the Moon!

Episode Date: July 1, 2013

Amanda Hendrix looks for and studies water in our solar system, where it has been found in surprising locales. Earth's moon, for instance. She talks about Luna’s ice and the weathering of its ancient surface.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Houston, the eagle has landed in a puddle 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 asking you to forgive me for that gross exaggeration. But we now know there is water on the moon. We'll talk about it with planetary scientist Amanda Hendricks. Bill Nye finds plenty of disagreement in Washington over space exploration, even as the commercial sector forges ahead. And Bruce Betts will join me for a look at the night sky,

along with your chance to win the new Planetary Radio t-shirt 2.0. Emily is away for several weeks, so we've asked Planetary Society contributing editor Jason Davis to fill her shoes. Jason, thanks so much for stepping in here while Emily is out of town. I'm really looking forward to talking to you about this latest piece that you've posted on your blog, which can be found like Emily's at planetary.org. I've got to start by saying, anybody who knows me knows I'm a big fan of the inverse square law. And so it's very disturbing knowing that the sun doesn't seem to obey it. And what is this spacecraft that's going out to investigate this situation?

Yeah, so this spacecraft is called IRIS. It's the Interface Region Imaging Spectrograph Spacecraft. What it does is right there in the title. It's examining this area of the sun known as the interface region. And that is a really funky, interesting region where the temperature in the sun's outer atmosphere jumps from about 20,000 degrees K to over a million in the outer corona. About 20,000 degrees K to over a million in the outer corona. And scientists don't fully understand exactly what's going on there that causes such a strange jump in temperature. And that's exactly what this spacecraft is going to be trying to help answer. It's crazy. I mean, you're supposed to feel less energy as you get farther from something. And so what is this spacecraft equipped with to make this investigation?

It has a single instrument. It's a cheap mission in the grand scheme of things. It's a small explorer mission for NASA. It's less than $120 million. So it only has one instrument, and that's an ultraviolet telescope. That means it's only going to see the portion of light coming from the sun that's in the ultraviolet, which are these very specific temperatures coming from this region. It's going to use a spectrograph. Essentially, they'll be

looking at the transition region of the Sun and trying to use the spectrograph to find out different components like temperature, density, and velocity. So they'll kind of be able to map out exactly what the material there is doing. All right, now tell us about the interesting way that this spacecraft made it up into this polar orbit. Yeah, so this was an airdropped launch. This is done by Orbital Sciences Corporation. You might be familiar with the Antares rocket that just lifted off for NASA's commercial spaceflight program.

They strap the rocket onto the belly of a large jet, fly out over the ocean, and drop it. And about three seconds later, it kicks on its solid rocket engines and flies into orbit from there. So fairly similar to what old guys like me remember of the X-15 and more recently, Spaceship One. It's an airborne launch. Exactly.

Yeah. Only instead of having Chuck Yeager in there breaking the sound barrier, you have a spacecraft that is going to go take a look at the sun. Well, let's hope that Iris helps to solve this mystery of this million degree, million degree, if you want to call it this, atmosphere, the corona surrounding the star that makes everything happen in our solar system. surrounding the star that makes everything happen in our solar system. Jason, great talking to you. I look forward to doing it again next week as you continue to fill in for Emily while she's out of town. Well, thanks, Matt. It's been a pleasure filling in, and I look forward to talking to you then. Jason Davis is a science journalist and a very regular contributing editor to Planetary.org.

That's where you can find his latest post, the one we've been talking about. Iris is safely in orbit, ready to eye the sun's atmosphere. Next up is the boss, Bill Nye, the science guy, the CEO of the Planetary Society. Bill, so much to talk about this week, largely because we found so many interesting stories in space news. One of them talking about what's going on in Congress, where it seems there is, I don't know, would you call it confusion? Discord. I might call it discord. People don't get along. Some people want the space launch system to fly. They want to fund it like crazy. Other people want a mission to Europa. Other people want to send humans beyond the moon to an asteroid toad there with a very, very large solar electric propulsion xenon drive.

And so there's only so much money to go around, and these people are pushing and shoving, Matt. Yeah, I'll tell you, you look at these things, and you've got Republicans against Republicans and Democrats against Democrats. It really does seem to go back to the old saying, all politics are local. Yeah, that's true. People still talk about how everyone worked together to send humans to the moon, how this united the United States. But right now, space exploration is dividing the United States. But we'll see what happens. world where we promote space exploration, everybody's concern is you don't want NASA, the world's largest space agency, to become a jobs program, a jobs agency, rather than an exploration agency.

You know, as they say, the trouble with politics, it's like sausage. You like the product, but you don't like the process. Don't watch it being made. In the meantime, you flip the page here and you see Europe apparently kind of running scared, redesigning rockets specifically to counter a company run by a quiet guy in Hawthorne, California. Well, a multi-billionaire. I mean, the guy who owns SpaceX, Elon Musk, is worth more than some countries. He is. Wow.

It's remarkable. He got crazy wealthy on PayPal, which many of us know and love. The thing is this is a case where the commercial industry is pushing the government industries. And that's probably a good thing, but it's a little bit unusual. Many of us of my age associate great space projects with governments. Landing on the moon took a government. And along with that is the mythic United Launch Alliance. It sort of de facto became a monopoly, and now it's getting competition.

So it should lower the cost of space exploration, but it's a tumultuous time. May you live in interesting times, say the Chinese, who will be part of this equation more and more so as time goes on. Something to watch, Bill. Thank you. Yeah, thank you. He's Bill Nye, the CEO of the Planetary Society, and we'll be talking to him again next week. But now we're going to talk about water on the moon, something that if you'd brought it up a few decades ago, you would have been laughed out of the room.

That's ridiculous. Amanda Hendricks is another of those planetary scientists that has been or still is a participant in almost more planetary missions than I can count. She recently finished many years at the Jet Propulsion Lab, most recently serving as Deputy Project Scientist on the Cassini mission. Now she works for the Planetary Science Institute. The change in jobs hasn't changed her fascination with the presence of water all over our solar system. Her work with ultraviolet spectroscopy has helped us understand that our own moon is not quite the desiccated husk we thought it was.

Amanda, welcome to Planetary Radio. Hi, Matt. Where are you? You're out of the country. I am. Right now I'm in Uppsala, Sweden, and I'm here for a Cassini Project Science Group meeting. And thank heaven for the wonders of Skype to allow us to speak to each other today. Yeah, I know. It's magical. It really is. So listen, our topic today is mostly based on this article that is in the brand new issue of the Planetary Report,

the magazine from the Planetary Society, titled Lunar Water and Weathering. Modern Spacecraft Reshape Our View of the Moon. Now, when I was growing up, everybody knew that the moon was drier than the driest bone. When did things start to change? Well, they really started to change, I would say, in about the 90s. The 1990s, we started getting some clues that the moon was, in some ways, perhaps a little bit more interesting than maybe we had thought. You know, I kind of think that the moon was a focus of, you know, the NASA program, of course, back in the Apollo days.

Sure, we had somebody to beat. Exactly, exactly. And then we kind of shifted focus and started doing deep spacecraft solar system measurements to Mars and even with the Voyager spacecraft out to the outer solar system. And I kind of feel like the moon was dropped a little bit. It was kind of forgotten like, oh, we've done that because we've been there and we sent people there. Been there, done that. However, yeah, exactly. However, there's still so much more to do than just go there and get samples. However, there's still so much more to do than just go there and get samples.

Because at that point, the moon had been mapped out at visual wavelengths with cameras, but it hadn't been mapped out at any other wavelengths. And there's so much to learn by looking in the infrared and radar wavelengths and UV wavelengths about the composition at different depths. So it's that UV stuff, the ultraviolet, the ultraviolet spectroscopy that you do, that I guess we can pay special attention to since that's your area of expertise. What is special about ultraviolet in this kind of work? One of the special things is that it actually doesn't probe very deeply into the surface. So we're looking just at the uppermost layers of the surface. And these are the layers that really get affected by different processes, especially weathering processes, such as

charged particle bombardment, which is really important on the moon because it is sitting out there unprotected by a magnetosphere or atmosphere in the solar wind. And it's constantly getting bombarded by charged particles like electrons and protons. We call that space weathering, and it can have both structural and compositional effects, really. It can change the surface, the composition of the surface and the structure of the surface. And so the UV is a good place to look for these effects, these weathering effects, because it's sensing that uppermost layer that really sees a lot of that. So you say the first evidence really started to

appear in the 1990s, missions like Clementine, I suppose. Yeah, but even before that, there were hints even from Galileo, because, and this was actually at visible wavelengths, but there were hints of an aqueous alteration feature at visible wavelengths. This was evidence for, tentative evidence for some sort of a temperature variation, perhaps a little bit more aqueous alteration at the higher latitudes, where we might expect it because that's where it's going to be colder. This is where we have these permanently shadowed areas. What's the term for those? Well, they're PSRs, permanently shadowed regions. However, those are really mainly at the very highest latitudes, really at the poles. This feature

that was seen in the Galileo data was Galileo didn't actually measure inside the PSRs. So there's a few effects going on. There was later evidence from Clementine at the polar regions that something was going on. And then we started paying attention to the PSRs. The PSRs don't get any sunlight. And so they're very cold, coldest regions on the moon. And these are areas where water can be stable because it is so cold there. When you say stable water, I mean, that also is surprising to many of us. Why doesn't that water in these permanently shaded areas, regions, why doesn't it just sublimate away? Right, because it's so cold.

It's 40 Kelvin, nearly minus 400 Fahrenheit in these regions. So the water likes it there, and it wants to be frozen, and it doesn't want to sublimate away. Okay, so I interrupted you as you were starting to talk about how we began to get even more evidence of this water. We had Clementine in the 90s and Lunar Prospector that gave us hints of something special going on at the polar regions. Then we started to recognize, well, maybe there's excess hydrogen at the poles and maybe it's concentrated in the PSRs. This began to kind of make sense, but it wasn't entirely clear, really, until more recently, just in the last few years, when M3, which is the moon mineralogy mapper on the Chandrayaan-1 spacecraft. That's the Indian lunar orbiter.

Exactly. It mapped out the moon, the lunar surface,-1 spacecraft. That's the Indian lunar orbiter. Exactly. It mapped out the moon, the lunar surface in the IR. And this is where you've got the distinct water ice absorption features at one and a half and two microns and three microns and an OH feature at about 2.8 microns. So M cubed mapped out the moon and mapped out the strength of the 3 micron and 2.8 micron features and found that it was stronger at the polar regions. By the way, M cubed wasn't measuring in the PSRs. So this was a whole new thing now, So this was a whole new thing now, that maybe there's water in some form or OH, certainly hydrogen-rich volatiles, even at low latitudes. And so what we're starting to learn is that there can be water at low latitudes, more at the higher latitudes, but even in the equatorial regions and at the equatorial regions when it's colder. So later in the day and earlier in the day. More from Amanda Hendricks about water and weathering on the moon is just a minute away. This is Planetary Radio. Hey, Bill Nye here, CEO of the Planetary Society, speaking to you from

PlanetFest 2012, the celebration of the Mars Science Laboratory rover Curiosity landing on the surface of Mars. This is taking us our next steps in following the water in the search for life to understand those two deep questions. Where did we come from and are we alone? This is the most exciting thing that people do and together we can advocate for planetary science and dare I say it, change the worlds. Hi, this is Emily Lakdawalla of the Planetary Society. We've spent the last year creating an informative, exciting, and beautiful new website. Your place in space is now open for business. You'll find a whole new look with lots of images, great stories, my popular blog, and new blogs from my colleagues and expert guests.

And as the world becomes more social, we are too, giving you the opportunity to join in through Facebook, Google+, Twitter, and much more. It's all at planetary.org. I hope you'll check it out. Welcome back to Planetary Radio. I'm Matt Kaplan. Amanda Hendricks of the Planetary Science Institute is my guest this week. She looks for water in every corner of our solar system, largely through her expertise

in ultraviolet spectroscopy. She was telling us before the break about great data returned by the Moon Mineralogy Mapper, or M-cubed, aboard India's Chandrayaan-1 lunar orbiter. There is a beautiful multicolored, a false-colored M-cubed image on the first page of your article in the Planetary Report. It really is quite beautiful. Are we beginning to get an idea then of how much water there actually is? Well, this is something that I think needs a lot more study. We don't think that there's very much, maybe up to a percent or two by weight, but perhaps there's more. I think that a lot of the measurements that we've made so far are not very well understood. And we need more lab experiments to help understand what the water

might be doing and how it might be stored. I mentioned that it's not going to be stable at lower latitudes midday because it's just too hot in it. As you mentioned, it's going to sublimate away. But it seems that it will bounce from warmer regions to cooler regions where it's going to be stable. So that needs to be better understood. And the water at different depths also might be transported and stored differently. Many of our listeners, probably most of them, remember the LCROSS mission that included crashing that Centaur section of a rocket into the moon. That had to reveal some things deeper down, or did it? It did. It sensed water in that plume that was produced by the impact, but that was in one specific region.

That was in a PSR. It's still very much an open question as to where this water came from? Well, I think we have several good ideas for where the water comes from. Some of it is likely to be primordial, present in the lunar interior from lunar formation, leftover. And this we know from some of the lunar samples that come from lunar mantle material. But then on the surface, there's water that can be created by solar wind bombardment. These protons that I mentioned come in and chemically interact with the oxygen that's in the lunar minerals and produce water.

And then comets also. You look at something like the moon. The nearest body that we regularly get to take a look at from Earth, just a quarter of a million miles away. And yet so much of this data came to us because we sent stuff there, not done for, this was not gathered from the surface of the Earth for the most part. It seems to say something about how important missions are elsewhere, not just to the moon, but everywhere in the solar system. Oh, it's so important. Orbiters are so important for mapping out the

surface of any body at multiple wavelengths. Even when you just think that you're doing it all just with IR wavelengths, there's so much more to be learned by studying other wavelengths. But mapping out a surface at high resolution with an orbiter, I almost think can't be beat. However, then you've got to go with a rover and get samples and all that too. You've been involved with so many missions and still are. This is, it looks like, a pretty important part of what you view as your career. I mean, something you really enjoy.

I really enjoy it. You know, I started out studying the moon with Galileo ultraviolet spectrometer data. So I'm excited to come back to the moon with an orbiter and study it further in the UV. Then I also have worked on Galileo data of the moons of Jupiter, which are different beasts. However, you know, we see water on those bodies, of course. And so I'm tying some of what I've learned from those bodies back to the moon. And then, of course, Cassini is still going strong at Saturn and doing all sorts of wonderful things, learning about the moons there and their interactions with their environments and their surface compositions. And

so I really enjoy studying small bodies in the solar system and their interactions. So I've got to ask, because I read that Vesta is your favorite asteroid. Is that just because Dawn hasn't reached Ceres yet? Oh, I know. I might change affections in a few years. No, I really, I think Vesta is obviously very interesting and fascinating body. But Ceres is very interesting on its own, too. And especially from a hydration perspective, you know, we have lots of evidence that it could be a hydrated body. So I really am looking forward to Dawn getting there.

So much more to look forward to and so much to be excited about it. About what we've learned just in recent decades within your career even around our solar system. It's really an exciting time in our solar system, I think. Amanda, I wish we had more time. Thank you so much. It has been delightful talking with you. Good luck as you continue to investigate water and so much more about the surfaces of all these worlds all around us. Thanks so much more about the surfaces of all these worlds all around us. Thanks so much, Matt.

Amanda Hendricks recently moved to the Planetary Science Institute after many years at JPL. She was the Cassini Deputy Project Scientist for a couple of those years at the Jet Propulsion Lab. She remains involved with that mission. She was on the Lunar Reconnaissance Orbiter mission as a participating scientist, I suppose still is. I'm betting that you still have that diorama of the solar system that you made in the third grade.

I do. It was in the second grade, actually. Even earlier. It's in a little shoebox, and it's got these little clay planets hanging down. Well, you protect that, take care of that. I know, I am. She was a planetary scientist right from the start. That's Amanda Hendricks. We'll be back with yet another planetary scientist.

That must be Bruce Betts for on the Skype line. It's time for What's Up on Planetary Radio. He's the director of projects for the Planetary Society. Mixing up phrases there. Welcome. Hey, welcome. Just want to start by mentioning our friend Kirby Runyon, longtime listener to the show, who's now working in this field. I think he's a post-grad someplace.

He loved that we did our piece last week at the Dog House, which he tried after we recommended it when he visited the Planetary Society last January. He says, great food and great memories. Oh, if only we were smart enough to get sponsorships for such things really i know it sounds like we're getting paid they don't even give us a free hot dog all right what's up well uh venus venus looking stunning low in the west after sunset it's that super bright star-like object over there in the west. Also, at the same time, you can check out Saturn, which will be in the south. We move on to this week in space history. A lot of good robotic goodness happening.

1997, Pathfinder lands successfully on Mars. 2005, Deep Impact slams an 800-kilogram ball of copper into an unsuspecting comet. an 800-kilogram ball of copper into an unsuspecting comet. And 10 years ago this week, launch of Opportunity rover, still happily roving around on Mars. I wonder if someday there will be those guys who go around and scavenge copper from buildings on Earth nowadays. Someday they're going to go out there. Yes, because that will make economic sense. We'll start with that asteroid. By the way, I just remember that Kirby is a grad student, not a post-grad. We don't want to advance him even further into poverty than we have to.

Okay, and now on to random space fact. That's cute. We think of the order of the planets from the sun as static, except for depending on how you count Pluto, it is. But the distance from Earth order of the planets is not static. That's just something that may be obvious to you. Maybe you never thought about it. But, for example, Mercury, which is, of course, closest to the Sun, is actually closer to the Earth than Venus right now, and does that fairly

frequently as it's on this side of the Sun, and Venus is closer to the quote-unquote other side of the Sun. So sometimes, like now, we're closer to Venus than we are, sorry, closer to Mercury than we are Venus, and sometimes the other way around. However, if you go to the planets that are farther out from Earth, the order does not change, always being the same. You shock me, sir. Maybe you should have your electrical connections fixed. Okay, so I asked you, how many Plutos would fit inside Jupiter if you could squish the Plutos up? How'd we do, Matt? You know, this got a very nice response.

It's one of those, I think, that it's like this useless bit of trivia, although it's interesting. It's nice to be able to tell people, yeah, well, yes, everybody knows that a thousand Earths will fit in Jupiter. But it took Steve Plonsky and a bunch of other people, Steve of West Bloomfield, Michigan, who is, by the way, our winner this week, to tell us there was a little bit of a range. They were all centered around 200,000 Pluto's. But a lot of people had this very precise number, 188,757.1. Is that what you've got for us? Well, approximately, but with the errors we've got in the size of Pluto and the uncertainty of how you define how big Jupiter is since it's a gas giant, I'd say you can't quite get that precise.

But, yeah, that would be the answer. Which, by the way, although I wouldn't have accepted it, technically is defined as a lot. Yes, that's one of the common terms of measurement, common people's terms of measurement, like the bread box and the football field. Yes, exactly. So a lot of people also said 224,000. But, Stephen, you are the winner of that brand new Planetary Radio t-shirt, the redesign of the Plan Rad shirt. And so we'll get that out in the mail to you very soon. Matt doesn't even let me see this.

You know, we have to ask the right people. It's some disparaging caricature of me, isn't it? It is. Yeah, absolutely. But you're at the center of the solar system, so everything's revolving around you. I think you should be pleased. Yeah, we'll see. I've got to mention this one from Randy Bottom. He came up with a considerably different number,

8.24 times 10 to the 25th Pluto's, the dog, would fit inside Jupiter, assuming the dog has a mass of 30 kilograms. Wolf. I was inspired to try that calculation. Now I'm going to have to try it. And, of course, it gets really weird if you just view him as a two-dimensional object. What are you talking about? Pluto's a real dog. I'm kidding.

I know he is. It's just whether he's real two-dimensionally or three-dimensionally. But in any case, he's real, and we love him. I've shaken his paw at Disneyland. How dare you? What? All right. We move on to less Pluton. Plutonian? Thank you.

There are five spacecraft, as many people know, that are on escape trajectories leaving our solar system. Besides those five, so not including the five that are on escape trajectories from our solar system, what is the farthest intact spacecraft from Earth at this time? Intact meaning not vaporized. Interesting. This is very intriguing. And for bonus praise, what's the second farthest? We will salute you if you get that second one, but we'll send you one of those brand-new Planetary Radio T-shirts

if you can tell us what that farthest spacecraft is that's not exiting our neighborhood. And, Bruce, how do they enter? Go to planetary.org slash radio contest. And when do they need to get that in by, Matt? By July 8th, the 8th of July. That's Monday at 2 p.m. Pacific time. And I think we're done. All right, everybody, go out there, look up at the night sky,

and think about ceramic plates. Thank you, and good night. He's Bruce Batts, the director of projects for the Planetary Society. He always licks the plate clean, at least when I'm around. He joins us every week here for What's Up. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by a grant from the Kenneth T. and Eileen L. Norris Foundation and by the Thirsty for Knowledge members of the Planetary Society.

Clear skies. Thank you.