To the moon


POSTED: Sunday, July 05, 2009

Three University of Hawaii scientists are participating in NASA's new missions to the moon to learn more about the environment for eventual human settlements.

Jeffrey Gillis-Davis, Paul Lucey and B. Ray Hawke, all with the Institute of Geophysics and Planetology, have different roles with the Lunar Reconnaissance Orbiter and Lunar CRater Observation and Sensing Satellite, or LCROSS.

Gillis-Davis, in an interview, said he is using data from the orbiter's radio frequency instrument to look for deposits on the moon from volcanic eruptions that occurred with fire fountains shooting lava into space.

The lava returned “;not as a layer of basalt, but as small beads or ball bearings,”; he said, citing samples of orange and green glass collected on Apollo missions that represent fire-fountain-type eruptions.

Gillis-Davis said he is studying the deposits as a possible resource for moon bases because the deposits can yield oxygen, iron and titanium. “;The oxygen part can be used for breathing or as a propellant,”; he said. The material also could be used potentially as building material, he said.

Scientifically, he said, the pyroclastic deposits “;will let us know about the inside of the moon, where the lavas come from. The lavas haven't changed much on their way up to the surface of the moon, so pyroclastic deposits represent the original composition of inner parts of the moon.

“;They may have entrained parts of the moon's mantle, because we know that happens on Earth in certain eruptions,”; he added. “;That would tell scientists a lot about composition of the moon's mantle and composition of the moon.”;

The orbiter, primary satellite for the mission, sat on top of the LCROSS spacecraft. They separated 45 minutes after launch from Cape Canaveral.

A NASA spokesman said, “;LCROSS has been the little mission that could.”; It is targeted to collide with the moon on Oct. 9.

Lucey said he and Hawke are supporting ground-based observations of the LCROSS impact flash at the Keck and NASA infrared telescopes on Mauna Kea.

The launch was timed for optimal viewing conditions from Mauna Kea's telescopes. NASA is encouraging amateur astronomers in Hawaii with backyard telescopes to take images and share them with the space agency because they could be scientifically valuable.

Lucey said the Keck and NASA Infrared Telescopes have instruments that are “;very sensitive to water and ionized water so if LCROSS lofts any ice into the sun, these telescopes should be able to confirm the presence of water in the expanding impact cloud.

“;Our particular role is to use our experience in observing the moon with Mauna Kea telescopes to help the other astronomers make sure they are pointing directly at the impact site at the south pole,”; he explained in an e-mail.

Lucey said he is also using the Lunar Orbiting Laser Altimeter to measure the difference in reflectance or brightness between the moon's night and day sides.

He said the reflectance of some lunar minerals is sensitive to temperature. The altimeter measures the strength of the return of each shot of its laser, in addition to the range to the moon, he said.

The scientists hope to make a map of the abundance of temperature-sensitive minerals by comparing laser return strength on the day side when temperatures are as high as 125 degrees Celsius to night-side measurements when temperatures are minus 175 degrees Celsius, he said.

Lucey said he also is using the orbiter's Diviner Lunar Radiometer Experiment to measure the moon's color in the infrared.

“;Like the portion of the spectrum that human eyes can see, the infrared has color, too, and this color can be used to determine what minerals are present at various locations on the moon,”; he said.

He said this is a major goal of the instrument, “;and my role is to lend my experience in telescopic observations in the same infrared wavelengths to the team of scientists analyzing the data.”;