Metro

Researchers find lunar surprises

By
Metro Editor
Thursday, October 28, 2010

The moon’s surface is surprisingly wet and complex, according to results from NASA’s Lunar Crater Observation and Sensing Satellite, or LCROSS, mission published Oct. 22.

LCROSS, which includes Brown researchers, intentionally slammed a rocket into the moon’s south pole last October. The collision sent debris sailing into the sunlight half a mile above, offering novel information about the chemical composition of the lunar surface.

Scientists detected concentrations of water high enough to provide astronauts with a viable source, whether that be purified for drinking or re-engineered for rocket fuel. Frozen grains of ice make up between 5.5 and 8.5 percent of the lunar soil at the poles.

“This is really fantastic,” said Brendan Hermalyn GS, who worked on the project. “It really does change our perception of the moon.”

Along with a team of scientists, Hermalyn and Professor of Geological Sciences Peter Schultz analyzed results from the rocket’s initial impact flash. Because no sunlight reaches the lunar south pole, the team used light from the collision itself to perform a spectroscopic analysis, which detected hydroxyl, carbon monoxide, carbon dioxide, ammonia, free sodium and silver.

Many of these compounds are highly volatile — easily evaporating — and were not detected in earlier samples from Apollo missions. The south pole sits in what is know as a “permanent shadow” region. Because it never receives light from the sun, temperatures remain low enough to preserve compounds in a stable state.

Apollo samples, on the other hand, were taken from warmer equatorial regions, Hermalyn said.

But it is not just the simple discovery of these compounds that excites Schultz and fellow researchers. It’s the stories the compounds may tell of the history of the moon, the Earth and the solar system as a whole. Elements may have arrived aboard comets, asteroids and meteorites that have slammed into the moon over the past billions of years.

“The moon is not a dead place that’s stagnant. There’s a lot of science still going on there,” Hermalyn said.

Of all lunar destinations, the poles represent the most remarkable chemical depository.

Unexpected, “strange” compounds have migrated to the frigid, permanently shadowed regions, Hermalyn said. “These are pristine areas of the moon that hold a treasure trove of material.”

But Shultz cited the fragility of the soil and cautioned against reckless future exploration.

“The concern is that if we start landing there and messing things up, we will not have this historical document,” Hermalyn said.

LCROSS is part of NASA’s Constellation Program, formed with the goal of sending astronauts back to the moon. Though President Barack Obama has promised increased funding for space exploration, he recently opted to hold back on this goal, instead encouraging private development in space flight.