AirSpaceMag.com

Water-bearing minerals on the Moon (in blue). (Chandrayaan M3 Team and NASA)

The extreme dryness of the Moon is established scientific dogma. The study of Apollo rock and soil samples pretty much had convinced scientists that the Moon has no water.  Because its surface is in a vacuum and experiences extreme temperature swings at the equator (from -150° to 100° C), the Moon was believed to have a bone dry surface.  Moreover,  minerals that make up the lunar rocks not only have no water, but crystallized in a very reducing, waterless environment, indicating no significant water at depth.

Yet, some irritating facts suggested that the whole story was more complicated. Water is being added to the lunar surface.  We know the Moon is bombarded with comets (mostly water ice) and meteorites rich in water-bearing minerals.  Additionally, the solar wind (mostly hydrogen atoms or protons) constantly hits the surface, implanting itself into the dust grains and a possible source for the creation of water.  An experiment laid out on the surface by the Apollo astronauts observed water vapor after the crew left the Moon.  It was thought this vapor might be latent out-gassing from the Lunar Module descent stage, but scientists couldn’t be sure.

So what happens to all this water?  Most of it is thought lost to space by a variety of processes, including dissociation by sunlight, thermal loss from the extremely high daytime temperatures, and sputtering induced by the impact of high-energy particles from space.  Some areas near the poles of the Moon are permanently dark and cold, so if any of this stray water happened into them, they would be “trapped” forever in the dark areas.  And although an extremely slow process, over millions of years a considerable amount of water ice might accumulate.  But we don’t know how much water is made and how much might be present on the Moon.

Just published results from spectral mapping instruments on three different spacecraft indicate the presence of large amounts of either water or the OH molecule in the soils of the Moon.  This water is present at high latitudes at both poles and occurs in sunlit areas (these instruments rely on reflected sunlight).  Although the authors of these new results don’t understand the source of this water, they favor the creation of water by the interaction of solar wind with surface minerals.  Solar wind protons reduce metal oxides in the soil, creating free metal (usually pure iron, Fe⁰) and water.  The M3 Team suggested that this water might act as a source for the water believed to be trapped in the dark polar cold traps.

What’s surprising about this new data is not the presence of water, but its pervasiveness.  The published image (above) shows this water to be present from the poles down to about 60° latitude.  This area subtends over 10 million square kilometers, or about one-third the surface area of the entire Moon!  Although the water appears to be present only in the upper few millimeters of the surface, its total mass could be enormous, greatly exceeding the several hundred million tones estimated to be present as ice in the dark areas of the poles.

As always with good science, the new results raise many more questions than they answer.  In part, this is a “chicken or egg” issue – do the newly discovered deposits result from surface alteration by water derived from the polar ice, or do they serve as a source for such deposits?  How does water form, move, get destroyed or get cold-trapped on the Moon?  What are rates of water deposition and removal?  What and where are the ice deposits and how pure might they be?  Right now we can only dimly perceive the beginnings of a whole new sub-discipline of lunar studies: polar geoscience.

This exciting story isn’t over.  More developments in this field are on the horizon.  Results from other experiments carried aboard the Chandrayaan-1 spacecraft, including my own Mini-SAR imaging radar, have yet to be fully reported.  The American Lunar Reconnaissance Orbiter (LRO) mission is settled into its mapping orbit and will be examining the Moon in detail over the next couple of years.  Every time we get new data from the Moon or examine and map it with some new technique, we learn new and surprising facts.

In a future post, I’ll examine the implications of large amounts of lunar water for human return to the Moon and the possibilities for a permanent sustainable presence on our nearest planetary neighbor.

Stay tuned – things are getting very interesting.

The more things change....

Over the long holiday weekend, Turner Classic Movies regaled us with a really obscure one – the 1960 biopic, I Aim at the Stars, starring Curd Jürgens.  This movie is a biography of Wernher von Braun, the German rocket scientist who built the V-2 for Hitler and the Saturn V for America.  Although no landmark in cinematic history, it was an interesting and reasonably well told story, even if it glossed over a few inconvenient facts about von Braun, like his nominal membership in Himmler’s SS.

What fascinated me in this movie (which I had not seen) was not von Braun, but the character played by James Daly, Major William Taggert (an intelligence officer in the U.S. Army who, having lost his family to a V-2 hitting London, hated von Braun and all of the Peenemunde rocket group).  After the war, Taggert follows the Germans as they relocate, first to White Sands and finally to Huntsville to continue their research into rocket flight.  Taggert becomes a reporter (his civilian occupation) who beats his media pulpit about the irrelevancy of space flight.  “All the money spent on space could build schools and hospitals instead!” he angrily harangues via television, a philosophical counterpoint to von Braun’s plea for an American satellite program.

Watching the movie, I was struck that this debate has been ongoing for the last 50 years.  Something about space exploration or human forays into new realms sticks in the craw of some people.  Although the context of the von Braun-Taggart argument was Sputnik and a possible American response, much has remained the same over these last 50 years.  The public still falls into two camps – those who believe that our survival depends on continued reach beyond Earth versus those who think it’s a waste of money or that the money could be better spent.  NASA spends most of its outreach efforts trying to win the hearts and minds of this latter group.

Case in point:  a NASA “white paper,” clearly a rough draft, leaked to the press, describing the post-Augustine space program.  Omitting the use of our Moon as the logical next step, “Generation Mars” is billed as the necessary pathway to keep NASA relevant, the public engaged and the required pipeline for sustainable product and group input cycles.  No more idiotic fooling around with, or distractions from, lunar bases.  The “exciting” destination is Mars – in about thirty years or so.  In the mean time, keep flying Shuttle so as not to upset the applecart.  Oh, and imagine, “use” the ISS for something (Just pull one or two studies—from the hundreds gathering dust—off the shelf of unfunded programs).

A key assumption here is that NASA’s survival revolves around an excited and engaged public.  The authors of this piece apparently think this will happen with Mars because the public doesn’t care about the Moon; that the Mars Generation can become “emotionally engaged because they will become contributors to the Mars goal and part of the maturation process in achieving it.”  Great stuff that – “emotional engagement,” not reason or logic.  The system of taking incremental steps using lunar resources to make space faring routine is abandoned for a multi-decadal agency program to take an “excited” public to Mars, a program “owned” by its contributors.  That’s a lot of time and work needed to engage, excite and own something.  It sounds like the description of an entitlement program, not a mission statement.

After 50 years of obvious benefits of space flight, many still are, at best, indifferent to it.  But even more significantly, few feel the need to be emotionally engaged with it.  People understand that along with our vast interstate road network, we have other vital economic infrastructure, such as railroad transportation, air traffic and more recently, a network of telecommunication satellites orbiting Earth.  We depend upon this infrastructure on a daily basis, but except for buffs, we do not get emotionally engaged in their day to day operations.

As no significant additional money is likely to materialize, we must strive for achievable goals and a paced rate of advancement.  A program that promises accomplishment thirty years in the future is not a program at all, but rather, an excuse to “study” the problem indefinitely.  In other words, it means another thirty years like the previous thirty years – lots of swell viewgraphs, color artwork of astronauts climbing the walls of Valles Marineris, and bureaucratic blither about exciting students.  But no actual spaceflight infrastructure.

I’ve touched on this issue before; no one votes for a candidate based on their position on the space program.  The net effect of this environment of public indifference is that NASA’s budget (which comes from an ever shrinking slice of the tax-funded, discretionary spending pie) will remain at existing levels for the foreseeable future.  What does this mean for NASA’s Mad Men advertising campaign for “Generation Mars?”  Basically it means that a space agency dependent upon public excitement to enrich its budget is one that is not likely to prosper.   With budgets devoured by countless cycles of viewgraphs, white papers and consensus management missives in the coming decades, what remains is an agency with no sustainable space exploration system.

To add space to our other national transportation networks, the kind that we take for granted but that contribute in so many ways to our prosperity and security, NASA needs to lay the groundwork for private industry to follow.  NASA needs to be the driver of private sector technology as it explores.  Without logical steps, NASA becomes the devourer of resources and not a technology driver.

As the next frontier is scouted, business will follow, as it always does.  Business is eager to follow.  NASA needs to finish laying the groundwork before moving on.   The Moon is the next destination in space.  Will America lead and  have a stake in this new land or will we stay behind and watch the movie?