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 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
Posted in Media, Missions, NASA, Science | No Comments »

“That’s Daddy’s rocket!”

Tuesday, August 25th, 2009

In an earlier post I wrote about the LCROSS mission, which is due to make its crash landing on the moon on October 9. (Mark your calendars!) In July I talked with Tony Colaprete, the Principal Investigator for the mission. I apologize if there is a bit of unevenness in this interview, because I have cobbled it together from three sources — our conversation at the Moon Fest, an e-mail, and his presentation at the Lunar Science Forum. Answers have been edited for length but I have tried to preserve Tony’s wording.

Tony Colaprete (NASA photo)

DM: You told me that you were born the week before the Apollo 11 landing. So, happy birthday! How big an inspiration have the Apollo missions been to you?

TC: I was born July 16, 1969, the day Apollo 11 launched. My father was heavily involved in the Apollo program, and one of my early childhood gifts was the classic Snoopy dressed in an EVA suit. So, yes, the Apollo mission was a huge influence, not only because they were so amazing but also because of my father’s involvement. … I am amazed to think that the folks who did Apollo were on average around 25 to 27 years old! The commitment, devotion, and guts those people had is inspiring.  I just hope I can do things half as right as they did for the Apollo program.

DM: When and how did you decide that you wanted a career in space exploration? How did you prepare for it?

TC: When I graduated from high school I knew I wanted to either go into the sciences or art. Luckily for us all, I decided to go into the sciences. … Very early on, though, I loved being in the woods near Boulder, Colorado, where I grew up. I would go for hours by myself and just watch what went on around me. So very early on I knew I loved systems, how things work together and influence each other … I still do.

I worked on instrumentation at the University of Colorado through the Space Grant College and the Laboratory for Atmospheric and Space Physics for a few years after getting my bachelors degree in physics. I was taking a few graduate classes (including my first planetary atmospheres class, taught by a very inspiring David Grinspoon), when I realized I wanted to pursue a graduate degree in planetary sciences. Luckily, CU is a great place to do that!

While I was doing my graduate work I continued to work on instrumentation for sounding rockets, space shuttle flights, and small spacecraft. This combination of science and engineering (again, systems!) was key, I think, to helping me get where I am now.

DM: How did the idea for the LCROSS mission come about?

TC: When LRO moved up to a bigger rocket, they had room for an extra 1000 kilograms on board, and a call for proposals went out for a co-manifested mission. And by the way, they said, you have only 2½ years to get it done, and you can’t spend more than $80 million.

When the call was announced, we [at NASA Ames] formed a “Tiger Team” to come up with ideas. Early on in the process we considered an impact mission, but I concluded that with only 1000 kilograms to work with, the impactor mass would be too small.

Another person in the group, Geoff Briggs, suggested using the spent upper stage of the launch vehicle. He has since said that he got the idea from someplace else. I ran some numbers and convinced myself that an impact by an object of about 2000 kilograms would produce a cloud observable from earth.

At about the same time, Northrop Grumman submitted a [proposal] that was also using the upper stage and also had a small shepherding satellite that could make observations. An engineer on the Tiger Team saw the idea and told me about it. We had a couple Northrop Grumman scientists come up and we discussed our ideas and the rest was history. So I don’t think it was any one person’s idea, but just enough people with the same idea!

In the end, LCROSS was selected out of 17 proposals. We cheated the 1000 kilogram limit — it’s 3200 kilograms, because we held on to the spent Centaur [rocket stage], which is about 2300 kilograms.

DM: Have you ever watched a launch in person before? If so, how was it different, knowing that it’s your own experiment that is going up?

TC: I’ve flown payloads on sounding rockets and shuttle flights, and have seen those go before. This Atlas moved so slow at first! I thought to myself, “You’d better pick up some speed or you’re not going to make it!” The sounding rockets and the shuttle use solid fuel, whereas the Atlas V is all liquid — it’s a big difference!

My biggest concern at launch was whether we could get off on the 17th or the 18th [of June], because those two days result in very good impact observing conditions for the continental U.S. The 19th was not so good, and on the 20th [there were no good times] at all. So I was very glad the weather broke in time for us  to go on  June 18.

DM: Have there been any exciting moments since the launch?

TC: I held my breath when we turned on the instruments for the first time. That was a moment of sheer terror and anxiety for me. Also, I’ll hold my breath again on August 1, when we turn them back on. Radiation and vacuum can have effects on detectors, so they always degrade over time. Once we know that they are working, I will be very confident that the payload will survive until the impact with the moon. [According to the mission page, the checkout of the infrared cameras and spectrometers on August 1 went very well. They took spectra of Earth and -- stop presses! -- detected oxygen, water, and vegetation! -- DM]

DM: What are you expecting to see when LCROSS hits the moon?

TC: There are a couple different models of how the water gets to the south pole and two different predictions for how it is distributed. We describe them as the smooth versus chunky models. In the smooth model, the ice is uniformly distributed on the scale of this room, with about a 1 percent concentration of ice. If that model is correct, LCROSS will have very good chances of detecting it. LCROSS should be sensitive down to concentrations of half a percent.

However, if the ice is chunky, with smaller pockets of up to 10 percent ice, then we might have a 10 percent chance of hitting something. If we hit one of the “peanuts” in the chunky peanut butter, we’ll know. This would immediately distinguish between the two competing models.

My biggest fear is that we won’t see anything — that it will be a dud. But even in that case, then we’ve learned that the distribution isn’t smooth. That is important to know, because it means that your next mission [i.e., a lander to search for ice on the ground -- DM] had better be mobile.

DM: How does the LCROSS mission compare with other spacecraft that have crash-landed on the moon (Lunar Prospector, the European SMART-1, and the Japanese Kaguya)?

TC: None of those other missions were designed as impactors. The biggest difference is that they typically hit the moon at a low, grazing angle, because they were in orbit around the moon. LCROSS is not, it’s in orbit around the Earth. [This is a rather non-obvious fact that is illustrated on the flight director's blog at this link. LCROSS doesn't "go to the moon." It goes into an orbit around Earth that is the size of the moon's orbit, and then the moon just runs into it! - DM] So it will hit at a very steep angle, around 85 degrees. Also, we’re bringing quite a bit of mass. So those missions can’t be compared to LCROSS for visibility, size, and impact angle.

DM: How big a crater will the LCROSS impact make?

TC: We’ve done simulations using Apollo-era technology, and we expect the crater to be about 20 meters wide — the size of a tennis court. We expect the plume to contain about 300 to 400 metric tons of material.

DM: On the LCROSS website you have a list of several possible target craters. Do you have a favorite on this list?

TC: Faustini would be my preference. It’s a very old, large crater, so the material in there has been in shadow for a very long time — around two and a half billion years. We want to hit somewhere that is flat and fluffy, not blocky and steep. One thing against it is that it’s right on the limb of the moon. So the ejecta have to go up 2 kilometers in order to be illuminated by the sun. In some of the other target craters, the ejecta only have to go up about 500 meters. But for earth observers, a position on the limb means that you get high contrast [against the darkness of space -- DM], and that’s good.

DM: I think it’s interesting how you have been able to use the results of other recent missions to narrow down the list of targets for this mission. Can you talk a little bit about  the synergy between missions, and especially the Japanese Kaguya spacecraft?

TC: The topography from their laser altimeter has been invaluable. First, it lets us calculate the slope of the ground. You don’t want to hit a slope [because you would then lose the benefit of a high impact angle -- DM]. Kaguya also gave us amazing information on the depth of the craters. Some of the errors in the previous estimates were significant, on the order of 500 meters to a kilometer. From the Kaguya terrain camera we got information on the surface roughness and albedo [reflectivity] of the craters. So, overall, they matured our current data set.

Also, with new LRO data coming online, we’ll be refining our numbers continuously to make the wisest choice of target. We will finally make an impact site selection by 30 days before impact, roughly the first week of September.

DM: How can ordinary people contribute to the LCROSS mission?

TC: Amateurs have already contributed, and with an impact with the moon high and the skies dark as far east as Texas, I hope many more will continue to contribute.

One thing to realize is that professional astronomers typically don’t point their telescopes at the moon. To most of them, the moon is a source of light pollution. So when we asked the best in the world to look at the moon for a change, there was a steep learning curve. One thing they needed to learn was how to find the crater you want to point to amongst a hundred or so other craters that look very similar. The shadows and bright areas change dramatically with small changes in the sun angle, so finding one’s way around the moon can be difficult if one has never looked before. To help, we asked the amateur community to image the moon at all phases and tilts so that we had a library of sorts for the various light conditions.

During the impact, amateurs with a minimum of about a 10-12 inch telescope can observe the impact. We will be soliciting these observations and will share them with others. [There is a Google Group for amateur observers at this link -- DM.]

DM: Finally, do your kids know that “Dad is a rocket scientist”? If so, are they proud of it, and are they paying any attention to the LCROSS mission?

TC: I have a son who is two and a half and a daughter who is five years old. They came to the launch, and when they look at the moon now they say, “Daddy’s rocket is flying to the moon!” After the launch my wife and children took a different flight home than I did. During the layover, on one of the cable news channels playing at the gate, they showed a replay of the launch. My children both yelled, “Daddy’s rocket!” My wife says that the people around them looked with a bit of a skeptical stare until she said, “Actually, it is their daddy’s rocket.”

Tags: Ames Research Center, Apollo, chunky, craters, interviews, Kaguya, LCROSS, LRO, Northrop Grumman, smooth, telescopes, Tony Colaprete
Posted in Missions, Science | 3 Comments »

A colder and wetter moon?

Wednesday, July 22nd, 2009

Yesterday I went to the Lunar Science Forum at Ames Research Center, which was the scientists’ version of a Moon Fest – a chance for all the recent and current moon missions to unveil their latest and greatest findings. According to the organizers, more than 500 people registered, including 200 just since last Friday. I don’t think that all these people actually came — the main meeting room holds 300, and it was not filled to capacity. Nevertheless, it was a well-attended (and well-Twittered) event.

Yesterday the science teams of the LRO and LCROSS missions, which just launched last month, presented their data publicly for the first time. As David Morrison, the head of the Lunar Science Institute, said in his introductory remarks, “Last year most of the papers reported plans, but I’m delighted to say that most of the talks this year are about results.”

All of the LRO results are very preliminary, because LRO is still in its “commissioning orbit,” when they are still warming up and checking out the systems. By the way, I mean warming up quite literally. Most of the instruments have residual moisture in them from their time on Earth. (So do most tourists, after a few hours in the humidity of south Florida!) So they have to go through a “bake-out” period to dry out all of that extra moisture. The LRO camera finished its bake-out on July 10, but even before then (as mentioned in this entry) it started sending back fabulous pictures.

Also, scientists from two other moon missions spoke yesterday. There was one presentation on the Japanese Kaguya mission that just ended a week before LRO lifted off, and three about the Indian Chandrayaan-1 mission that is still ongoing.

The most interesting news yesterday all had to do with results that we can’t really talk about yet! One of them is so preliminary that no one can really interpret it yet. The other two are results that are going to be published soon but are currently under “embargo,” meaning that the scientists aren’t supposed to talk about them until the publications come out.

First, David Paige, principal investigator for LRO’s Diviner experiment, showed some of Diviner’s first measures of the temperatures in the moon’s permanently shadowed craters. Remember that these are supposed to be “cold traps,” where water molecules could perhaps accumulate as ice because they are too cold to float away. The first temperature readings in Amundsen crater turned out to be even lower than expected: around 33 degrees Kelvin (or 33 degrees above absolute zero).

No one had predicted such a low temperature; I think that 70 degrees Kelvin was closer to what they had expected. As Paige said, “If this is true, it’s colder than the poles of Pluto!”

From his wording, you might correctly infer that Paige is not really sure this measurement is right. The instrument has been calibrated, but he said there are some possible reasons why the instrument-measured temperature may not be the same as the physical temperature. (For example, they don’t really know what kind of surface they are looking at — rocky or soft and fluffy — and that can make a difference to how they estimate the temperature.) The instrument is still too fresh and new, and the finding too unexpected, to put a lot of stock in it yet. But what it could mean is that the permanently shadowed craters are a better cold trap than we thought.

Two other surprising results that can’t be talked about yet came out of the Chandrayaan-1 mission. Carle Pieters of Brown University reported on the Moon Mineralogy Mapper, and said that her team had made a new discovery on lunar volatiles that she can’t discuss yet. Of course, the most important potential  ”lunar volatile” is water. But, she said, “Don’t give me wine and try to dig the secret out of me.”

Then Paul Spudis, whose Once and Future Moon blog is always thought-provoking, talked about the results from his mini-SAR (synthetic aperture radar) experiment, which is also on the Indian Chandrayaan-1 spacecraft. Like Pieters, he has a result that he can’t talk about yet, but he said, “I may be susceptible to being plied with drinks!”

Mini-SAR is also looking for water ice; the idea is that ice will reflect a circularly polarized radar beam differently from rocks. (The radar wave will actually go into the ice before bouncing back, because ice is transparent.) This is similar to the way that ice was first detected at the south pole, by the Clementine mission in 1994; Spudis was the deputy leader of the Clementine science team. However, the Clementine satellite only got one brief peek at the south pole, and so its results were very ambiguous. You can’t do very much in science with one data point. Chandrayaan-1 should do much better. We will have to wait to find out just how much better it’s done.

Nevertheless, I will transcribe a fascinating exchange that occurred during the audience-questions period after Spudis’ talk. Clive Neal, the chair of NASA’s Lunar Exploration Analysis Group (which advises NASA on the choice of moon missions) went to the microphone.

NEAL: You said there were some things that you cannot talk about, but then you proceeded to talk about some of them… (Laughter from audience.)

SPUDIS: You don’t know that! (Laughter.) You’re making an assumption, and maybe it’s warranted, maybe it isn’t.

NEAL: So I’ll ask my question as delicately as I can. You showed data that seemed to be consistent with the presence of water ice on the moon. Would you care to comment on that? (Loud laughter.)

SPUDIS. No! (Laughter.) But you’re welcome to draw whatever conclusions you care to.

NEAL: Can I just rephrase the question? If I buy you a beer, would you comment?

SPUDIS: It depends on what kind of beer and how much. (Laughter.)

DAVID MORRISON: I think all of us are beginning to assume that in a month or two we’ll have a wetter moon than we do now.

SPUDIS: Well, the moon isn’t going to change. (Laughter and applause.) Our perceptions might change. But, you know, some of us have had this perception for a long time.

Make of it what you will! Just don’t blame me for breaking any embargoes.

Other tidbits and factoids from the first day of the meeting:

These roads are so confusing.

• Google released its new version of Google Moon on Monday, and there was a large screen in the tent demonstrating it. It’s a huge improvement over the previous map-based Google Moon. This one has all the latest imagery from the LRO mission, and will continue to be updated constantly — so look for it to continue improving by leaps and bounds over the next year.
• The LRO launch was perfect, and that is very good news for the scientists, because it means that there is more fuel left for an extended mission than they could previously count on. Craig Tooley said that this could extend the life of the mission by a year. (The spacecraft has a planned one-year life span, followed by a two-year extended science mission. I interpret Tooley’s remarks to mean that it could continue orbiting for a fourth year.) I would think that the extra time would be especially valuable for the narrow-angle camera, which can only image about 10 percent of the moon in any given year.
• I asked Sam Lawrence, of the LRO camera team, whether they had felt under any pressure to get the pictures of the Apollo landing sites out early. He said, “I won’t lie to you. Several people in Headquarters simultaneously and independently came up with the idea of taking pictures of the Apollo landing sites. But Isaac Newton is in the driver’s seat. It was largely serendipity that we happened to be in the right place to image them.” In fact, the Apollo 12 landing site has not been imaged yet, but it should come around into the camera’s view in a couple of weeks.
• There was lots of Twittering going on at this conference. I sat behind someone whose laptop had a screen full of twitters. I have so far refused to get on twitter.com, but those of you who are might want to check out what the scientists are twittering about.
• Yes, there is such a thing as a free lunch! Registration for this conference was free (which is already unusual for a scientific meeting) and the Lunar Science Institute provided the lunch and refreshments free of charge, too! Shhh… Don’t tell Washington that they’re using your tax money to feed starving scientists …

Tags: Ames Research Center, beer, Chandrayaan, cold trap, free lunch, Google, ice, Kaguya, LCROSS, LRO, Lunar Science Forum, Lunar Science Institute, Twitter, water
Posted in Just for Fun, Missions, Science | 1 Comment »

And in other news, the sky is blue …

Friday, July 17th, 2009

What is It?

Can you tell what you are looking at in this picture? Hint: In the dead center of the picture, look for something that doesn’t cast a shadow like anything else. Instead of a depression, look for a tiny bright spot that casts a long shadow horizontally across the moon’s surface.

Did you find it? You’re looking at the Apollo 11 Lunar Module! (Actually, it’s just the descent stage, which remained on the moon when Neil Armstrong and Buzz Aldrin took off in the ascent stage.)

The Lunar Reconnaissance Orbiter (LRO) took the picture earlier this month, along with photographs of all the other Apollo landing sites except for Apollo 12. NASA released all the photographs today.

This is a piece of news that SHOULD be about as surprising as, “Scientists today released photographic proof that the sky is blue.” Nevertheless, it is actually huge, because there has been a small but vocal contingent of people claiming in recent years that all of the Apollo moon landings were faked. They even managed to convince the Fox television network to run a special about the “moon hoax” a few years ago. It’s now going to get a lot harder for them to make their case.

The place you should go to read about all of this is Phil Plait’s wonderful blog, Bad Astronomy. Plait has run a website and a blog for years that debunks silly claims like UFOs, faces on Mars, etc. … and one of the battles that he has fought all this time is the one against the moon-hoaxers. So for him, the release of these NASA images must be a huge personal triumph.

What’s so great about it is that here is one case where the conspiracy theorists have gotten themselves trapped — they have occupied a position that can slowly, bit by bit, get chopped out from underneath them, as the LRO missions and other missions get higher- and higher-resolution pictures. This is something that we can only dream of in some of the other contentious non-debates that science has to deal with. Imagine, for example, that we could actually go back into the past and get photographic proof of evolution happening … but we’ll never be able to do that. And so the evolutionism versus creationism non-debate will go on forever. However, for the moon-hoax non-debate, I think the end may be in sight.

Now let’s put that aside, like a bad dream, and also appreciate these pictures for what they show. I love the Apollo 11 picture precisely because the Apollo 11 lander is so different from anything else in the picture. It really says, “We are the aliens here.”

Next, here is part of the photograph of the Apollo 14 landing site.

Apollo 14 Landing Site

Here the lighting was so good that you can actually see the astronauts’ footprints leading from the lander (right) to the Apollo Lunar Surface Experiments Package (left of center). Amazing! Of course, as my wife said, “Are those footprints or footprint-shaped craters?” 

Also the photograph of the Apollo 16 landing site documents another little bit of Apollo history:

Apollo 16 landing site

In this one you can see the shadow of the lander extending all the way across a nearby crater. Apollo 16 came perilously close to landing in this crater, and the photo shows what a close call it was. Quoting from David M. Harland’s book, Exploring the Moon: The Apollo Expeditions: “They were in the centre of a subdued crater about 100 metres wide. What they did not discover until they ventured outside, was that the rear footpad was a mere 3 metres beyond the rim of the 15 metre crater that Young had lost sight of [while landing the LM]. When he had hovered to select a spot on which to land, he was directly over the crater, and had narrowly missed landing on the rim.”

Fascinating stuff, and a wonderful 40th-anniversary treat from NASA!

Tags: Apollo, Apollo 11, David Harland, footprints, landers, LRO, lunar surface, Phil Plait
Posted in Media, Missions | 3 Comments »

New Moon Crater Discovered, or Why You Shouldn’t Pack Your Globe in a Suitcase

Monday, July 6th, 2009

In my last entry I wrote about the first LRO image, which was acquired over a narrow swath of territory near a crater with the curious name of Hell. Naturally, I wanted to see where this crater was, so I got out my lunar globe.

So first I have to tell you a story about this globe. I bought it at the Johnson Space Center gift shop in 2003, while I was attending the Lunar and Planetary Science Conference in Houston. At that time my book was almost ready to come out — in fact, I think the publication date was only a week or two after the conference ended. I saw this globe in the gift shop, and thought it would be a good idea for me to have a lunar globe that I could refer to when I was giving book readings. Seventy-five dollars later, the globe was mine. They were probably glad to get rid of it; after all, who goes around buying lunar globes these days? In fact, the globe came with an information booklet that clearly had not been updated since the early 1970s.

Unfortunately, I decided to bring the globe back home in my suitcase. As my wife will tell you, I don’t have a lot of common sense. And when I got back to California, I discovered my beautiful new lunar globe … with two new craters that hadn’t been there before.

One of them happens to be close to the place that I was writing about in my last blog post. So when I showed my wife where Hell Crater was, she deadpanned: “That’s a hella crater, all right!”

Don't Let This Happen to Your Globe

Tags: LPSC, LRO, spousal overunit
Posted in Just for Fun | 2 Comments »

LRO First Picture!

Saturday, July 4th, 2009

Two days ago, on July 2, NASA released the first photograph from the new Lunar Reconnaissance Orbiter. And here it is! (Actually, this is just a small piece of it, but a very interesting piece, as I will explain below.)

LRO First Light

The complete photograph is actually a very long strip, something like 500 by 50,000 pixels, taken near the edge of Mare Nubium in the moon’s southern hemisphere. The LRO website ways that the photo was taken near a crater called Hell … I’m not sure why. It doesn’t seem like the best place to start a mission!

If you want to find the location through a telescope or binoculars, it’s at about 30 degrees south latitude and 10 degrees west longitude. To the south is Tycho (one of the brightest craters on the moon), and to the north is an easily spotted trio of craters, Ptolemy, Alphonsus, and Arzachel. The best time for looking at this region was two days ago, when the picture was taken — and that is no accident. Photographers on Earth like to take pictures at sunset or sunrise, and so do lunar photographers! The lunar topography shows up most clearly near the “terminator” — the boundary between the day side and night side of the moon. The LRO spacecraft is currently in a terminator orbit, circling the moon from pole to pole and following the moon shadow around. This is the place to be if you want to take stunning photographs!

There are two very interesting things to notice in this picture. First, at the very bottom, you might notice a string of craters, like beads on a chain. Is this an accident? If not, how is a chain of craters like this formed? The answer is that they are “secondary craters” — craters formed by debris that is blasted off the moon’s surface by a meteorite impact. When the debris lands, it forms smaller craters all in a line. The first person to notice this phenomenon, I believe (perhaps some historians can correct me if I’m wrong) was Ralph Baldwin, an amateur astronomer in the 1940s. At the time, the conventional wisdom was that the moon’s craters were volcanoes. Baldwin put together many pieces of evidence, like this, to conclude that at least some of them were formed by impacts.  In this case, the amateur was right and the professionals were wrong.

Also, Baldwin noticed very large-scale linear patterns on the moon, which again seem to radiate outward from some of the great basin impacts. According to the LRO team, you can see some of the linear features in the photograph. I suspect that what they mean is the overall southwest-northeast orientation of the valleys in this photo. These furrows must have been scoured out by a vastly larger and earlier impact than the one that made the little chain of craters that I mentioned above.

As cool as the LRO pictures are, I want to mention that LRO is way, WAY more than just a camera. It has seven extremely cool instruments on it. I will list them below in no particular order of coolness. I will not translate the abbreviations into English — if you want to know what they stand for, check out the LRO website.

1. LAMP. How cool is this? We are going to see the dark regions of the moon by starlight. The stars give off ultraviolet light, and the whole darned galaxy glows at one particular wavelength, and we can use this invisible (to human eyes) light to peer into craters that never see the sun.
2. Diviner. We’re going to take the moon’s temperature. It’s not the same everywhere. Equatorial regions range from 150 degrees below zero (Celsius) to more than 100 degrees above zero (i.e., hotter than the boiling point of water).If you’re building a lunar base, that’s kind of tough to deal with. But near the poles, the temperature is much more even, although cold — roughly 100 to 120 degrees below zero.
3. CRaTER. This one is interesting because it is specifically directed towards human habitation. How much radiation does the moon get from the sun and from outer space? The answer will tell us how long we can keep astronauts on the moon’s surface safely. Remember that the Apollo astronauts were there for only three days or less.
4. LEND. Another instrument that will measure radiation — this time neutrons coming from inside the moon. This is kind of a repeat of the experiment that Lunar Prospector did to confirm the presence of hydrogen (and therefore maybe water) at the poles. An interesting point here is that it’s a Russian experiment flying on a NASA spacecraft — a nice example of international collaboration!
5. LOLA. This laser altimeter will construct 3-D images of the moon’s surface.
6. Mini-RF. A synthetic aperture radar that will search for ice at the lunar poles. This is similar to the Clementine experiment in 1994 that started all the excitement about water at the poles, but I assume it will be much better because it will have a lot more time to gather data and because it was designed for this purpose.
7. LROC, the LRO camera, which by now needs no introduction.

I am by no means an expert in all of these technologies (or any of them), but I hope that over the coming months I will have a chance to interview some of the scientists involved with these projects, so that I can tell you how they work.

One thing that I find interesting about the web links is that almost all of them mention that they are “heritage” or “legacy” instruments — in other words, similar experiments have flown on other NASA missions, to Mars or to other planets. In our budget-conscious age, NASA wants equipment that is cheap and reliable. Still, one can’t help feeling a little bit nostalgic for the 1960s and the Apollo missions, when nothing was a legacy experiment — everything was being done for the first time!

Tags: craters, equator, ice, LRO, NASA, opinions, poles, radiation, technology, telescope, water
Posted in Missions, Science | 5 Comments »

Liftoff!

Friday, July 3rd, 2009

We’re on our way!

To all space enthusiasts, especially those who are interested in the moon, welcome! I’m celebrating the launch of my blog, appropriately enough, with a picture of a rocket launch. On June 18, 2009, NASA successfully sent its first two lunar missions of this millennium into orbit: the Lunar Reconnaissance Orbiter (LRO) and Lunar Crater Observation and Sensing Satellite (LCROSS). (Image credit: United Launch Alliance/ Pat Corkery.)

LRO Logo in center, LCROSS just above it

It’s an exciting time to start a moon blog. Not only have the LRO and LCROSS missions gotten underway, but also the Indian Chandrayaan-1 mission is still going and the Japanese Kaguya mission has just ended. We also have a big anniversary coming up: the fortieth anniversary of the Apollo 11 manned mission to the moon. Two days after that, the longest total solar eclipse of the 21st century will take place — and as you know, we wouldn’t have eclipses without the moon.

That is a sample of the topics I plan to cover in my blog. I also hope to include interviews with people who are working on moon-related projects, whether they be NASA or private, science or literature or art. Yes, I do intend this blog to be not just about lunar science. The moon plays a large role in our culture, so I don’t think that we should just stick it in a box labeled “Science” and forget about all the other things that the moon means to us. But that’s a topic, or discussion, or rant for another time!

This blog takes its name from the working title of a book that I wrote six years ago, which was published by John Wiley & Sons: The Big Splat, or How Our Moon Came to Be. It’s a figure of speech my grandfather used to employ often. If you “think so-and-so hung the moon,” that is another way of saying that you are a great admirer of said person.

Eventually, my editor and I decided that “Who Hung the Moon?” was not an appropriate title for the book. The main reason, for him, was that book titles should not be in the form of a question. This was news to me — hadn’t he ever heard of “Who’s Afraid of Virginia Woolf?”? My reasons were different. I was concerned that “hung the moon” might be an idiom from a specific region — the American South — and not everyone would understand it. And finally, “Who Hung the Moon?” didn’t quite say what the book was about. The title we chose, The Big Splat, or How Our Moon Came to Be, was a much more straightforward description of the book’s contents.

Nevertheless, I still like the abandoned title. But it was actually my SO (Spousal Overunit), Kay, who suggested reviving it as the title for this blog. She did more than suggest it — she designed the whole look of this webpage around it, so that by the time she was done I couldn’t possibly say no! If you like the design, please send your compliments to her (and check out her quilting blog, www.allaboutapplique.net).

See the “About” pages if you want to read more about my background and reasons for writing this blog. But now, let’s get started!

Tags: Apollo, Chandrayaan, eclipse, Kaguya, LCROSS, LRO, NASA, spousal overunit, The Big Splat
Posted in Missions | 4 Comments »