LI scientists help discover new types of lunar rocks

New types of lunar rocks have been discovered by Long Island scientists and a team of NASA collaborators, 41 years after moon-walking astronauts first visited Earth's closest neighbor and brought back samples.

The discovery made through detailed images beamed to Earth by a moon-observing spacecraft suggests the history of the celestial body is far more complex than previously thought.

"I don't know if I should toot my own horn but this is a pretty big discovery," said Timothy Glotch, assistant professor of geosciences at Stony Brook University and lead scientist in a project that involved teams from NASA's Jet Propulsion Laboratory in Pasadena, Calif., UCLA and NASA's Ames facility at Moffett Field, Calif.

Two types of rocks - granite and rhyolite - never before spotted during previous spacecraft flybys or when surface samples were scooped up by human explorers between 1969 and 1972, are now known to pervade at least five regions of the moon. They provide fresh, new evidence of cataclysmic volcanoes that helped shape the lay of the lunar landscape.

Granite and rhyolite are two volcanic rock forms that are very familiar to Earth-dwellers because both are widely dispersed on this planet and are also remnants of volcanic activity. But while volcanoes continue to reshape Earth, the moon's volcanoes have been dead for eons.

Using data from the Diviner radiometer, an instrument aboard the Lunar Reconnaissance Orbiter, which was launched last year, scientists were able to pinpoint previously unseen compositional differences in the moon's crustal highlands.

"The reason we had not made the discovery earlier is we never sent the right type of instruments," Glotch said of previous unmanned spacecraft, which used X-ray technology to study the lunar landscape and could not discern the presence of granite and rhyolite. The Diviner's technology, however, allowed him and his colleagues to discern the rocks' "spectral signature" and open a new chapter on the moon's fiery origins billions of years ago.

Although he said tiny grains of granite were seen in rock samples brought back to Earth by Apollo Mission astronauts, the infinitesimal flecks did not provide strong evidence to support a vast presence.

Glotch's research is one of two papers in Friday's journal Science. The second, led by James Head of Brown University, has produced the most detailed map to date of the moon's craters. Using a laser altimeter aboard the orbiter, Head pinpointed 50,000 craters in one 20-kilometer area.

Glotch will lecture on the moon at 7:30 p.m. Saturday, in celebration of International Observe the Moon Night in Stony Brook's Earth and Space Science Building. At 8:30, weather permitting, he will lead telescopic observations of the moon on the building's roof. The event is open to the public.