New Scientist article

Tuesday, April 6th, 2010

My article for New Scientist about the discovery of more-abundant-than-expected lunar water finally reached the newsstands last week. I’d like to welcome any readers of that article who have come to this blog looking for more information.

This article had quite a long gestation period. I first pitched the idea of an article about the LCROSS mission to my editor about a year and a half ago, but at the time she didn’t really see the news value of the story. Before the LCROSS mission lifted off, there wasn’t a whole lot of excitement about it in the media. But then a lot of things changed. The Chandrayaan-1 discovery of surface water on the moon. David Letterman’s skit that poked fun at the idea of “bombing the moon.” The very successful impact that dug up a lot of water, plus other volatile compounds.

At the same time, a big policy debate was going on about our future in space, with the Augustine Commission issuing its report about the same time as LCROSS was hitting its target. That debate culminated in February, when President Obama recommended the cancellation of the Constellation Program and redirected NASA’s priorities for the next decade.

With all of these things going on, I think it is fair to say that the moon and lunar water was one of the top stories in solar system science over the last few months.

I wrote the first draft of the New Scientist article in December, following the Lunar Exploration Analysis Group meeting in Houston (November) and the American Geophysical Union meeting in San Francisco (December). I really wanted the article to come out then, when it could still (maybe, in some far-fetched scenario) have had some effect on the policy debate.

However, the article got delayed until April, not for any political reasons but just because New Scientist feature articles get put into a queue and it takes some time for them to work their way through that queue. Meanwhile, the Obama decision happened and so I had to revise the article to reflect that reality.

In the end, I failed in my original goal of writing an article that would perhaps have an influence on the future. However, I do think that the article itself came out a little bit stronger as a result of the delay. I was able to replace some of the “ifs” and “possibly”s and “could be”s with more definite statements. In some sense it became a retrospective on the lunar water story of 2009, rather than a story-in-progress as I originally conceived it. However, I would like to emphasize that there is still a story in progress, as the LCROSS data and LRO data continue to come in and become better understood.

Tags: Augustine Commission, Chandrayaan-1, David Letterman, LCROSS, LRO, New Scientist, Obama, retrospective, water
Posted in Media, Meetings, Missions, NASA, Science | No Comments »

There is No Santa Claus; Is There an Enterprise?

Saturday, January 30th, 2010

For months we’ve been waiting to hear what the Obama administration response would be to the Augustine Commission report on the future of NASA’s manned space flight program. Now it looks as if we have our answer, and it ain’t pretty.

The Augustine Commission outlined four possible directions for NASA. The last two were called “Flexible Path” and “Moon First.” The first two could be called “Moon Never” (though the report used different names). The commission further argued that in order to have a human space program that our country could be proud of, NASA’s budget would have to be augmented by about $3 billion per year.

As reported here and here and many other places, it looks as if President Obama has now placed his bets on the more ambitious of the two versions of “Moon Never.” Here is what I wrote about this option in my post from September:

Moon Never, ISS on Life Support. Slightly more palatable, this option also abandons hope for sending humans beyond low Earth orbit, but it at least acknowledges that it would be a disgrace to build a space station for 25 years, operate it for 5 years, and then torpedo it. The Augustine committee said that we can keep the ISS going to 2020 by developing a smaller heavy-launch rocket and relying on commercial companies to generate cheaper alternatives for launching humans into orbit.

This pretty much describes what I have read about the proposal Obama is going to send to Congress, although we can now paint in a few more details. There is some talk that the space budget will increase by $1 billion per year (not $3 billion per year). In early January, the word was that this money was going to go to NASA but now looks as if it might go in part toward incentives for private companies to build launch solutions. Obama is definitely scuttling the Constellation program and its associated rocket, the Ares I-X. This is a bridge-burning move. Even if we changed our minds and wanted to send astronauts to the moon by 2020, or even the mid-2020s, without Constellation we wouldn’t have the hardware to get them there.

Of course I am disappointed by this decision. However, it was not the least bit surprising. In today’s economy, with talk of a budget freeze on discretionary spending, where was Obama going to find $3 billion? I consider some of the online criticism of his decision to be disingenuous; I suspect that many of his critics would have jumped on him, perhaps even harder, if he had chosen to ask Congress for another $3 billion per year for NASA.

I’m disappointed that Obama didn’t take more seriously the commission’s finding that NASA needed this money to have any kind of credible manned flight program. It wasn’t really a choice between $18 billion and $21 billion. It was a choice between $18 billion flushed down the toilet, or $21 billion producing tangible results.

I’m disappointed also that there was no acknowledgement of the fact that, after the discoveries this fall concerning lunar water, the moon is actually an interesting destination again. Even if we concede that short-term financial considerations prevent us from having a viable human spaceflight program for a few years, a leader who was truly committed to space would outline a long-term strategy and a rationale that would include sustainable presence in space as its #1 objective. The best arguments I have seen in that direction are the ones on Paul Spudis’s blog. When you make that the rationale, the moon becomes a required destination, not an optional one.

However, I do see some reason for optimism in Obama’s decision, bleak as it may seem. It really does mark a break with the past. Gone is the pretense that NASA can do everything. Until now, there was always the hope that there was a Santa Claus, that the U.S. government or taxpayers would somehow step in and make NASA’s wishes come true. It’s possible that this was in some way holding back the efforts of private companies and investors to think creatively about what they could accomplish in space.

Now, there is no other game in town. We will only get as far in space as international partners and private companies, such as SpaceX, can take us. Lovers of free enterprise should be delighted; this is a chance to show that entrepreneurs can be better at “the vision thing” than presidents. For the near future, it seems, we are hitching our wagon to a starship named Enterprise.

I personally have some doubts. I’m not sure that space exploration companies are ready to walk on their own two feet. But we are going to find out, one way or the other.

A metaphor for the future of human spaceflight?

(Image from www.startrek.com.)

Tags: Augustine Commission, Barack Obama, disappointment, Flexible Path, reality, sustainability, the vision thing
Posted in Arrive, Future exploration, Media, NASA, Popular culture | 1 Comment »

Guide to the Cosmos, gold, New Scientist

Monday, January 11th, 2010

As of today, I’m on a podcast! Check out “Guide to the Cosmos,” a podcast hosted by Dr. Robert Piccioni, at www.guidetothecosmos.com. It was actually Christmas Eve Day when we recorded this interview over the phone, and it’s a two-parter. The first part, in today’s episode, is about water on the moon, and I talk all about the recent discoveries by Chandrayaan-1 and LCROSS. The second part is about the origin of the moon, and that part of the interview will air in February.

The audio part of the podcast is actually on a different site, called WebTalkRadio. You can go to their main site, www.webtalkradio.net, and then look for “Guide to the Cosmos” under the “Show podcasts” tab. But I’ll make it easy for you and give you a direct link. Dr. Piccioni also puts some images up on his own website to go with the podcast, which you can look at here as you listen to the interview.

When I recorded the interview I did not know which images he was going to have up on his website, so I wasn’t able to refer to them directly. Let me fill in that gap here. Image #1 shows the impact plume from LCROSS’s crash into the Cabeus crater.

Cabeus impact plume

This cloud of debris was not visible from Earth. The photo was taken from the “shepherding satellite” that passed directly overhead and crashed into the moon 4 minutes later. The spectrometers on the shepherding satellite analyzed both the absorbed and emitted light from this cloud to look for traces of water and other compounds. Image #2 is just a pretty picture of the full moon, nothing else. The LCROSS impact happened way down at the bottom of that picture, in the bumpy area around the south pole. Image #3 is a “wiggly line” from the ultraviolet and visible spectrometer.

Spectrum showing sodium emission line plus something interesting

Interestingly, this is not the data set that Tony Colaprete, the main project scientist, has talked about the most. Unlike the near infrared spectrometer, whose readings they understand pretty well and which show definitive evidence of water, the UV/VIS spectrum requires more interpretation and they are just beginning to work on it. The peak on the right is actually not water but sodium. (This emission band looks yellow to the naked eye, and explains why a sodium lamp is yellow. See this Wikipedia entry to read more about it.)

You can also see two shorter peaks on the left that have not been identified yet. At the AGU meeting in December, Tony said they think that one of them could be gold! Yes, gold on the moon. You read about it here first.

Back in the days before Apollo went to the moon, there was a slightly kooky scientist named Tommy Gold who said that the moon was covered by a layer of dust so deep that any spacecraft that landed on the moon would just sink into it and never be seen again. Fortunately, this didn’t turn out to be the case, but for a while NASA had to take the possibility seriously, and his hypothetical surface layer became known as “Gold dust.” But now lunar gold dust may take on a whole new meaning!

I did not report on this earlier (“LCROSS Strikes Gold!”) because they really don’t know what the peaks are yet, and so Tony’s comment was at least partly meant in jest. If they ever get more serious about it, I’ll be sure to let you know.

Last month I wrote an article for New Scientist online about the moon sessions at the AGU meeting, called “Are We Looking in the Wrong Places for Water on the Moon?” This was a very ticklish article to write, but I was happy with it in the end. Basically, the story is that one of the instruments on the Lunar Reconnaissance Orbiter (LRO) has been seeing lots of indications of water in places where it isn’t supposed to be.

LCROSS went to a permanently shadowed crater because that is where theory says that lunar water, if it exists, should concentrate. It went to Cabeus, in particular, because that is where the Lunar Exploration Neutron Detector (LEND) on LRO saw the highest concentrations of water. But what’s interesting, and controversial, is that LEND has seen no correlation so far between permanent shadowing and hydrogen deposits! There are other regions with just as much water as Cabeus that aren’t in shadow.

What made the article ticklish to write is that there are some people who frankly don’t believe the LEND data yet. I tried to hint at this without pouring oil onto the fire. But there are three groups–one in Russia, two in the U.S.–who are working on the LEND data and they all are saying pretty much the same thing. You can’t just ignore this fact and pretend it isn’t there, while at the same time singing the praises of LCROSS and the LRO camera and the other experiments on LRO. That’s why I felt it was important to write this article, even if the jury is still out on what the results mean.

In a blog I think I can be more adventurous than I can in print, so I’ll hazard a guess as to what it might mean. The LCROSS results are hinting that there is way more water than you can produce by bombarding the moon’s surface with the solar wind–some of the water has to be from meteoroids or comets. LEND can see beneath the surface, and Igor Mitrofanov, the principal investigator for LEND, says that he thinks they are seeing deposits of hydrogen that lie beneath the surface, covered by a layer of dry soil. Putting two and two together, I think that the water is delivered by meteoroids/comets, and is then buried by some process we don’t understand yet (or maybe it’s just in a sufficiently thick layer to begin with?). Once it’s buried, it doesn’t need a permanently shadowed crater to keep it from evaporating. Sure, it might be associated with a permanently shadowed crater, but really any crater will do. Or maybe even something that isn’t a crater! One of the most puzzling things about the LEND data was that one of the hydrogen deposits seemed to be on one side of a mountain range. But maybe that makes sense, if the mountain range was created by the meteoroid/comet impact.

Well, this is just my feeble amateur speculation. The specialists will, of course, hash it out and either come up with an explanation, or agree to disagree. One thing that’s pretty certain is that there is a lot we don’t know yet.

Tags: Chandrayaan-1, hydrogen, LCROSS, LEND, lunar origin, New Scientist, podcast, Robert Piccioni, Thomas Gold, water, WebTalkRadio
Posted in Media, Meetings, Missions, NASA, Science, websites | 2 Comments »

Naked Astronauts, etc.

Tuesday, December 15th, 2009

Sometimes the best questions are facetious.

This morning I was attending the moon sessions at the American Geophysical Union conference in San Francisco. One of the talks was by Justin Kasper, who works on the cosmic ray detection experiment (CRaTER) on the Lunar Reconnaissance Orbiter. After his talk, one of the audience members (Mark Robinson of the LRO Camera team) asked what have to be the most unexpected questions of the meeting:

“So, is an astronaut’s suit dangerous? In a theoretical sense, would it be better for an astronaut to go naked?”

Before I tell you the answer, let me tell you why the question is not as crazy as it seems.

Kasper had just reported on the most unexpected finding so far by the cosmic ray experiment. It was supposed to measure how much radiation on the moon is coming from outer space (cosmic rays) and the sun (mostly protons from the solar wind). But they have found that the moon itself is a significant source of radiation.

In open space, CRaTER counted about 33 cosmic rays per second. (By the way, that’s an unusually high number. The sun is currently in one of the most quiet phases ever recorded in its magnetic cycle, which means that it is not doing as good a job as usual of blocking cosmic rays from outside the solar system.) When LRO got into lunar orbit, about 50 kilometers above the surface, the count dropped to 22 cosmic rays per second. Sounds great — you’re safer on the moon than in outer space.

But here’s the catch. If you’re on the moon, the moon ought to block half the cosmic rays coming from outer space! Even if you’re orbiting 50 kilometers above the moon, the moon should still block about 14 out of 33 cosmic rays, letting only 19 through. Because CRaTER is recording 22 per second, the remainder of the radiation (3 events per second) must be coming from the moon!

At this point, they can’t be sure why, but Kasper conjectured that this radiation is produced by cosmic rays that hit the surface, smash up an atomic nucleus, and re-radiate back into space.

What does this have to do with space suits? Well, your space suit contains lots of heavy atomic nuclei for the cosmic rays to smash into. So if you’re an astronaut, you’re going to be exposed to some radiation emanating from your space suit, for the same reason. That’s why Robinson asked his question.

Now really we don’t recommend future astronauts to do the full moon-ty. There are good reasons for wearing a space suit, such as the inconvenient fact that humans need air to breathe. However, Kasper did say that we should think carefully about what we make space suits out of. Are some materials better at absorbing cosmic rays than others? It’s also relevant for building shelters on the moon. “The results suggest that building a wall is a little more helpful than building an umbrella,” he said.

Actually, this comment was facetious too, because a flimsy umbrella isn’t going to help you much against cosmic rays. In an interview last week, Jack Burns of the University of Colorado, a science advisor for NASA, told me that one of the best defenses against cosmic rays is actually a tank of water. (That is one more reason why discovering water on the moon is important.)

Tags: AGU, cosmic rays, full monty, LRO, radiation, sun
Posted in Future exploration, Just for Fun, Meetings, NASA, Science | 1 Comment »

LEAG Conference, part 2

Thursday, November 26th, 2009

While the LEAG meeting in Houston last week featured lots of exciting new results from LCROSS and LRO, it also provided an opportunity for discussion about the future of lunar exploration, human spaceflight, and NASA. The main theme of the meeting was sustainability: If and when humans return to the moon, how do they do so in a sustainable way?

One point that everyone (as far as I could tell) agreed on is that the Apollo model is not sustainable. By “the Apollo model” I mean what the lunar scientists like to call “sorties.” You build an enormous rocket, you take everything you need with you, you leave all of your junk there and you never use it again.

An alternative approach would be incremental or cumulative. You would probably start with several robotic precursor missions that would establish where your key resources are, and perform technology demos. Can we extract oxygen from lunar rocks? Can we extract water from lunar soils? Can we control lunar dust so that it doesn’t get into everything and cause all of our machines to break down? Can we safeguard astronauts from radiation?

If we find satisfactory answers to these questions, then we can build a base on the moon, although another possibility would be a base at the L1 point (or Lagrange point) where Earth’s gravity and the moon’s gravity cancel each other out. The things that you need to bring from Earth are brought a little bit at a time, somewhat like the way that we built the International Space Station. You don’t just go there, use your stuff once, and leave it. You need to re-use as much as you can. And finally, if there is anything that you can produce onsite, you do it. That primarily means (at this stage of the discussion) water, atmosphere, food, and propellant.

What I’ve just said may seem obvious, but it was surprisingly non-obvious for a very long time. Those of us who lived through the Apollo era were very surprised when the trips to the moon stopped. A lot has been written about the possible reasons: the public’s apathy, the Cold War politics that went into the moon race, the Vietnam War that sapped the American budget, etc. But maybe it had to happen. The whole approach was unsustainable.

Even now, many people still want to reproduce the Apollo model as we prepare for missions to Mars. This was the chief criticism that I heard of the Augustine Commission report. The “Flexible Path” option, many people felt, was just “Apollo on steroids,” traveling to more places with one-shot missions instead of building up the infrastructure for a sustainable presence in space.

I suppose I should name some names here. Paul Spudis is an especially passionate advocate of the idea that we must think about sustainability when we return to space. I wish I could just copy his whole presentation here, but that would not be very original. He said, “The goal is not to excite the public. The public must see the value in lunar exploration, which is different from making it exciting.” He took issue with the Augustine Commission’s conclusion that the ultimate destination (their words) is Mars. “The goal of returning to the moon is to become a spacefaring species,” he said. I think this is a great mission statement. Mars is not the ultimate goal; the ultimate is to be able to go wherever we want. Spudis would build up that capability on the moon.

Also, Igor Mitrofanov gave a perspective from the Russian space agency: “We will support missions to the moon if we will go there forever. Then we will participate as a nation.” He compared the moon to a new continent: “The first explorers looked for a place for a settlement, a bay, a harbor,” he said. Obviously he is arguing for a base approach rather than a sortie approach.

Many participants in the meeting said that sustainability would have to mean economic viability. Paul Spudis, as usual, formulated the question nicely, by listing three stages of lunar exploration: Arrive, Survive, Thrive. So far we have shown that we can Arrive. The next step is Survival — showing that we can stay for a long time on the moon — but ultimately the point of the whole exercise is to Thrive.

Both Spudis and Bob Wegeng, of the Pacific Northwest National Laboratory, drew analogies with the development of railroads in the 19th century. I went to lunch with Wegeng, who exposited at length about the railroads and told me some things that I did not know before. In school (in the U.S., at least), we all hear about the golden spike that completed the first transcontinental railroad in 1869. It’s part of our national mythology, just as much as the moon landing 100 years later. But that railroad went bankrupt several times, in spite of all of its government support!

The first economically successful transcontinental railroad, according to Wegeng, was the Great Northern Railway, built by James Jerome Hill. Wikipedia says it  was ”the first transcontinental built without public money and … one of the few transcontinental railroads not to go bankrupt.” Hill built up the Great Northern’s customer base by selling homesteads to farmers along the railroad route and even building industrial plants that would be served by his railroad.

If we want to learn from this example, it suggests that we will Thrive on the moon when a mega-corporation comes along, led by one person with vision, which does not just focus on the transportation technology but constructs a whole econosphere on the moon.

Who could that mega-corporation be? Not the current aerospace companies; they are too much like the government-backed railroads that failed. What about Google? I don’t know. It seems a little bit outside of their skill set, but they do have the vision. All things considered, the vision is probably more important than the skills or the capital, which can always be acquired on the way.

Anyway, getting back to the LEAG meeting, the one presentation that really looked at the moon from an economic point of view was by Brad Blair, a mining engineer who also works with the Canadian Space Agency. His paper was actually out of date — he presented an economic analysis of investing in the moon that he published back in 2002 or 2003. He analyzed five different scenarios, and in the last, ridiculously optimistic scenario he showed a possible return on investment in the range of $3 to $4 billion. I think the importance of his study lies not so much in the specific numbers or conclusions but in the methodology. I think his work needs to be updated for the decade of the 2010s. The discussion of lunar exploration has been completely dominated so far by scientists and engineers, but at some point some economists need to get involved.

Finally, in the discussion of sustainability, there were some interesting points made about public opinion. Spudis calls it the “50-50-50 problem”: public support for NASA has hovered around 50 percent for and 50 percent against for 50 years. And that includes the supposed heyday of NASA when we were racing to beat the Russians to the moon. Even back then, there were a lot of people who didn’t see the point, and argued that the money would be better spent solving problems on Earth. Public support for NASA has never been significantly more than 60 percent or less than 40 percent.

Spudis’ point was that if our justification for exploring space is “inspiring the public,” then we will never succeed. We need to go beyond inspiration to providing economic value.

At the same time, someone (I’m not sure who) pointed out from the audience that 50 percent support is not really a bad thing. Politicians are glad to have 50 percent, because it means they can be re-elected. Popular support for a lot of our public institutions runs a good deal lower than 50 percent. So instead of asking what NASA is doing wrong, perhaps we should advertise the fact that they are doing something right. Message to politicians: If you invest money in NASA, about half of the population will support you, as they have now for half a century.

The big unknown, at this moment, is whether any politicians are listening … especially the ones that matter, who live at 1600 Pennsylvania Avenue.

Tags: Apollo, Augustine Commission, base, Economy, James Jerome Hill, LEAG, Paul Spudis, Politics, railroads, resources, sustainability
Posted in Arrive, Future exploration, Meetings, NASA, Survive, Thrive | 6 Comments »

LEAG Conference, part 1

Thursday, November 19th, 2009

I’m back from the Lunar Exploration Analysis Group (LEAG) meeting in Houston, which ran from Monday through Wednesday this week. There was plenty of talk about LCROSS, which one member of the LCROSS science team calls “the little mission that did,” and also lots of discussion about the future of lunar exploration. The big theme of the meeting was sustainability: How do we go back to the moon in such a way that we can keep on going there indefinitely? Many, though not all, of the participants interpreted that question to mean: How can we make the moon economically viable? Of course, the LCROSS mission has a great deal to say about that.

Of course, the talk I looked forward to the most was by Tony Colaprete, the principal investigator for LCROSS. He gave only a few more scraps of information beyond what was reported in the news conference last Friday, but nevertheless I felt that the scraps fit together into an interesting story, which I wrote for the New Scientist website. You can find it here. I concentrated on the discovery of other volatiles besides water, because that was clearly what most interested the people I talked with.

I had to do a little soul-searching, because I go a little farther in the article than Colaprete would go in saying where the water and volatiles probably came from. But isn’t that my job as a journalist? If the experts are pretty sure about piece A, and they are pretty sure about piece B, and if there is only one way that piece A and piece B fit together and everybody knows it, shouldn’t I tell the public about that? Or do I have to wait until, ta-dah!, they hold a press conference and say they are ready to draw conclusion C?

Anyway, there were lots of other interesting and fun things at the meeting. For my blog I will concentrate on personal impressions rather than scientific news.

First, one thing I really loved about this meeting was how much joking and camaraderie there was. I don’t know whether it’s because it is a small enough community that everybody knows each other, or because certain people who are leaders in the community set the tone with their irreverence, or whether it’s just because everyone was in high spirits over the LRO and LCROSS results (and let’s not forget the Chandrayaan-1 results before that). Or maybe it’s just because geologists and planetary scientists are by nature goofy people.

Anyway, the big running joke at the meeting was Larry Taylor’s shorts. After the LCROSS press conference, he was quoted by the New York Times saying that he would have to “eat his shorts.” He was one of the scientists during the Apollo days who came to the conclusion — with good cause, I might add — that the moon rocks were “bone dry” and did not have a scrap of water. He told me that his grandfather used to say that he would “eat his shorts” if he were proved wrong, and so Larry told the newspaper reporter that he would have to eat his shorts now that water had been found in abundance. He had no expectation that this quote would be featured prominently in the Publication of Record. But then he got about 50 e-mails the next day asking if he would have a side of fries with the shorts, and what else he wanted to eat along with them. At the meeting several speakers ribbed him about this, and he finally said that he would eat them if they were served with a bottle of Guinness. Well, with unbelievable alacrity, a four-pack of Guinness beer materialized at the front of the lecture hall! I’m afraid I am not sure whether he eventually made good on his promise (I rather doubt it), but it shows how much fun people had at this meeting.

One of my favorite moments from the meeting was listening to a conversation between Wendell Mendell, another scientist who has been around since the glory days of NASA in the early 1970s, and Igor Mitrofanov, who is sort of his Russian equivalent. They swapped stories about the beginning of the Space Age. Mitrofanov described how when Sergei Korolev wanted to launch the first Russian satellite, he went to the Academy of Sciences, who of course loaded it down with more and more things that they wanted the satellite to do. It looked as if it would take forever, and Korolev was worried that the Americans would launch a satellite first. So he went to Khrushchev, the leader of the Soviet Union, and asked if he could launch a satellite that would just go beep beep beep. Khrushchev said sure, and Sputnik was born. Khruschchev didn’t think much of it, but when Sputnik flew in October 1957 and he saw how panicked the Americans were, he called Korolev back into his office and said, “I want another satellite by November!” (The over-complicated Academy of Sciences satellite did finally get launched, Mitrofanov said, but it was their third satellite.)

Mendell said that President Eisenhower was actually glad to have the Russians launch the first satellite … until he saw the furor that it caused. He wanted to be able to fly satellites over Russia to take spy pictures, because the U-2 airplanes that were doing this job were at risk of being shot down. If the Russians launched the first satellite, they couldn’t very well complain when the Americans launched one of their own. Nice plan, until everyone in the U.S. got hysterical about Sputnik, and the U.S.’s first attempt at a satellite launch blew up.

I guess these stories are probably pretty well known, at least the U.S. side, but I loved the idea of these two scientists, once separated by an Iron Curtain, being able to talk and laugh about these things.

More meeting thoughts and recollections in my next post …

Tags: Chandrayaan-1, Dwight Eisenhower, economics, humor, Igor Mitrofanov, LCROSS, LRO, New Scientist, Nikita Khrushchev, Sergei Korolyev, Sputnik, sustainability, Tony Colaprete, Wendell Mendell
Posted in Just for Fun, Meetings, NASA, Science | 4 Comments »

Water on the Moon — Bring your Buckets!

Friday, November 13th, 2009

As usual, the LCROSS press conference had a lot of Power Point slides, but probably the most memorable thing about it was an empty 2-gallon industrial bucket. Tony Colaprete, the lead scientist for the mission, said: “I’m here today to tell you that yes, indeed, we found water on the moon, and we didn’t just find a little, but we found a significant amount.” Then he held up the bucket. ”In the 20-30 meter wide impact crater that LCROSS made, we found about a dozen of these 2-gallon buckets. And that is probably a lower bound.”

Let me back up and give a little bit of context. Earlier missions, Clementine and Lunar Prospector, had found evidence for water ice but no direct proof. This year, three different missions simultaneously reported proof of water ice, because they detected not just the spectral signature of hydrogen (H) but also the hydroxyl molecule (OH). [It doesn't take too much knowledge of chemistry to see that hydrogen, H, plus hydroxyl, OH, equals water, HOH.] Not only that, the hydroxyl comes and goes over the course of a lunar day, which suggests that there is some chemistry going on at the moon’s surface. Carle Pieters, the principal investigator for the Chandrayaan-1 mission’s Moon Mineralogy Mapper, estimated that you could get a liter of water from a football field-sized area of the moon’s surface. This was exciting news, but as a reality check, it still makes the moon drier than Earth’s driest desert.

LCROSS has found an oasis in the desert. It was targeted for a specific crater near the south pole, Cabeus, where remote sensors had detected a high concentration of hydrogen. It excavated a 30-meter crater, only a third the size of a football field. Within that region, it dug up not just a liter of water, but 100 liters. Again, for context, one reporter asked Colaprete how this compares with Earth’s driest deserts. He said, “If you stand on that beach [the sandy spot where LCROSS impacted], I can say that it is wetter than some deserts on Earth.”

Does this contradict the Chandrayaan-1 findings? Of course not. It just re-emphasizes how little we know. Chandrayaan-1′s measurements were taken over a broad swath of the moon. By comparison, LCROSS is just looking at a tiny pinprick on the surface. Also, Chandrayaan-1 was measuring only the water that is right at the surface, up to a few microns deep. On the other hand, LCROSS excavated to several meters below the surface. To me that was one of the most exciting things about LCROSS; unlike measurements from orbit, it really sees what is underground. (However, it turns out that I was not entirely correct when I thought that LCROSS would be the first mission to do this. Radar measurements can penetrate one or two meters. Chandrayaan-1 carried a radar instrument on board, but those results have not been published yet. When they do get published, Paul Spudis promises me that they will be good.)

So basically, we now have one data point where we had zero before. We know that at one particular location, we have found an oasis. It remains to be seen exactly how concentrated the water ice is there, how heterogeneous it is, how hard it is to find other areas with lots of water, how deeply it is buried, etc. Not only that, there is a whole new suite of questions: How does water get to the moon? Once it’s there, how does it get transported to the poles? There are lots of theories, and at this point absolutely no way to choose among them.

What we have here is the appearance, in less than two months (since Pieters’ paper), of a whole new field of science that didn’t exist before: lunar hydrology. The next step, of course, will be for the LCROSS team to continue analyzing their data and nail down the concentration of water at their impact site. Also, LRO (the Lunar Reconnaissance Observer) will continue making large-scale observations  to figure out where else on the moon we might find water. But then, if we’re really serious about following up on this discovery, the next step needs to be a lunar rover (or even several of them) to poke around these permanently shadowed craters and start answering the questions in the previous paragraph.

There was one other very interesting thing mentioned at the press conference, which Colaprete was clearly eager to say more about but he just doesn’t have the data yet. LCROSS found lots of other volatile elements in the debris plume and/or the vapor cloud released by the impact. These may include:

• carbon dioxide
• methane
• methanol
• ethanol
• ammonia
• other organic molecules

The case for these is not as clear yet as the case for water. Colaprete said that it is absolutely certain that some of them are present, but they can’t yet pin down which ones and in what amounts. The science team is going to continue working hard to answer those questions, but they felt that the detection of water was so clear and of such overriding importance that they voted to go public with it now (instead of waiting another month, as per the original plan). But still, stay tuned for news about these other volatile compounds, because this story ain’t over yet.

Tags: buckets, carbon dioxide, Carle Pieters, Chandrayaan-1, hydrology, LCROSS, LRO, methane, oasis, Paul Spudis, Tony Colaprete, volatile compounds, water
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LCROSS Results Tomorrow

Thursday, November 12th, 2009

Last month the LCROSS satellite crashed into a crater near the Moon’s south pole, in an experiment designed to look for water ice. At that time the principal investigator, Tony Colaprete, said that they would probably announce the results from the mission within two months. Well, they’ve beaten that timeline by a month. Tomorrow there will be a press conference at NASA Ames at 9:00 am Pacific time (12 noon Eastern time) to announce the first findings.

As I wrote in my previous post, the LCROSS impact was sort of a dud from the point of view of public relations.  It was not possible to see the debris plume from an amateur telescope, as the mission planners had hoped. Nevertheless, the instruments on the spacecraft definitely did see the debris. Thus, from an engineering point of view, the mission was a success. They landed the spacecraft where they wanted to land it and they got data.

So that leaves one more question: Was the mission a success scientifically? And in particular, did they find water? That’s the question that I am almost certain will be answered, one way or another, tomorrow. And of course it is the most important question from the viewpoint of future exploration of the moon.

I don’t have any inside information, but Tony Colaprete did say this in an e-mail to me a couple weeks ago: “We have a wonderful data set … It amazes me a little more each and every day.” Read into those tea leaves whatever you will!

In related news, Colaprete and other members of the LCROSS and LRO missions are going to present their early results next week in Houston, at the annual meeting of the Lunar Exploration Analysis Group. Of course the press conference tomorrow will cover anything really big and important, but I’m sure there will be many more details and more discussion at the Houston meeting.

Fortunately, New Scientist has commissioned me to write an article about the status of the lunar water question, taking into account all the results that have been announced this year, from Kaguya to Chandrayaan-1 to LRO and LCROSS. I will attend the Houston meeting, and this will give me a chance to do lots of interviews.

I think we are now at a crossroads in lunar exploration. We’ve gotten a big influx of new data this year, with tantalizing signs that there is more water than we expected on the moon. Now is the time for planning the next steps. Do we shrug our shoulders? Do we invest $3 billion more into the NASA manned flight program, as the Augustine Commission suggested? Do we plan new robotic missions? If so, what should they do?

Lots of questions. Hopefully I’ll find out a few answers, starting tomorrow.

Tags: Houston, LCROSS, LEAG, New Scientist, Tony Colaprete, water
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Craters in the Dark …

Friday, October 9th, 2009

The moon has two new craters in it today, courtesy of NASA and the LCROSS mission. Along with hundreds of thousands of other people, I got up before 4:00 this morning to watch the live coverage of the impact. It was … well, anticlimactic. But I’ll get to that below.

It gave me an amazing sense of deja vu to see live coverage, from a NASA spacecraft, of the moon getting larger and larger. It’s been only 37 years since the last time … Welcome back, moon! Nice to see you again!

Impact site is below and to the left of the prominent crater (center). NASA photo.

Of course, this was very different from the Apollo missions. The difference was especially apparent when the second spacecraft (the “shepherding satellite”) hit the moon. There was no astronaut saying from the moon, “Tranquillity Base here. The Eagle has landed.” Instead, we got the flight controller saying from a control room in Mountain View, California, “Flight shepherding spacecraft impact, stations report LOS [loss of signal]. Last tracking at 11:35:35.054 seconds.” And then, that was it. From the operational point of view, the mission was over. The controllers got up, exchanged high fives, and started milling about the control room. If this had been a manned mission, or even a soft landing of a robotic mission, the work would be just beginning. It was weird for it to be over so abruptly.

Just a few seconds earlier, there was an interesting comment from the science control room: “We confirm thermal signature of the crater over mid-IR camera.” For anyone wanting live, real-time science, this was it. As the chief scientist, Tony Colaprete, explained later in the press conference, the infrared camera saw a distinct bright spot, a little over a pixel wide, that was the hot, newly formed crater from the Centaur rocket impact. He was clearly jazzed about this detection, which they weren’t sure that they were going to be able to make. The ultraviolet spectrometers also got excellent readouts that should contain lots of information about the material that was thrown up by the impact. But Colaprete wouldn’t say, or even speculate, what they have seen yet. The main thing he wanted to emphasize was that the instruments worked and they got the data they wanted.

The press conference was kind of interesting to watch because it was clear that the story the media found interesting was exactly the opposite of the spin that NASA would like to put on the landing. None of the four speakers mentioned this, but it was clearly written on one of the slides taken from an Earth-based telescope: No plume detected.

Reporters are trained, of course, to look for the elephant in the room that nobody is talking about. They homed in on what Tony Colaprete, Jennifer Heldmann and Michael Wargo weren’t saying — the fact that none of the ground-based telescopes were reporting any visual evidence of the impact. I really think that the scientists should have acknowledged this up front. A lot of the publicity and a lot of the planning of the mission was built around the premise that the debris plume would be visible from Earth, certainly through the big professional telescopes in California and Hawaii, but even through a 10-12 inch amateur telescope. But it wasn’t. I think that the reporters were right to question the scientists on why no plume was seen (yet) and what this might mean.

However, though “no plume” might be the big news story at the moment, it is very far from the end of the story. The scientific work of the mission is just beginning. The press conference was held two hours after impact. But the more relevant time frames are two days (the time that will be spent with the full science team at NASA-Ames collecting data), two weeks (when they will meet again and start drawing their initial conclusions), and two months (when they are likely to make a public announcement of the results). Tony Colaprete and Michael Wargo made the following very important points:

1. It is not clear yet that the plume wasn’t detected. Further image processing could reveal that it was there, but fainter than expected. “Gray on black,” as Wargo said.
2. Even if the plume wasn’t detected, the crater was detected, and it was about the expected size. Its thermal signal will give a lot of information about what was at the impact site.
3. Colaprete kept coming back over and over to the point that “spectra are where the science is at.” The spectrometers are more sensitive than the cameras, and they tell you what the chemicals are that you are looking at. For the most part the readout is not instant (although Colaprete did talk about a clear sodium line).
4. Finally, Wargo reminded the reporters that this was an experiment. An experiment, by definition, is something whose result you don’t know in advance. You might have a prediction or a theory, but until you do the experiment you just aren’t sure what is going to happen. So the plume was smaller or darker or less dramatic than expected. That will still tell us something.

So the press conference was an interesting clash of cultures. The media like pretty pictures, big explosions, and dramatic discoveries. They don’t like to wait. The scientists, as Jennifer Heldmann said, like “squiggly lines” (like the output of a spectrometer). They understand the value of patience and gathering all the evidence before you reach a conclusion.

If you want to know whether LCROSS saw water ice on the moon, your best bet is to stay tuned. The answer is likely to come out at the American Geophysical Union (AGU) meeting in December, in San Francisco. I’ll be there!

P.S. Maybe I was wrong about the media spin being different from the NASA spin. Here’s a mainstream media article that barely mentions the lack of a visible plume.

Tags: anticlimax, deja vu, ice, impact, LCROSS, plume, science culture, spectrometer, squiggly lines
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