Pieters

PROVIDENCE — There may not be enough for astronauts to someday go skating, but some scientists suspect that there’s ice on the moon.

You wouldn’t be able to see it through a telescope. If it’s there, it’s probably at the poles, in a crater perpetually shielded from sunlight.

But Carle Pieters is going to be looking.

It’s just one thing the Brown University planetary geologist and her colleagues will be scouting for as members of the team analyzing data from one of 11 instruments aboard the Chandrayaan-1, the Indian spacecraft that went into orbit around the moon earlier this month.

Pieters is the principal investigator for the Moon Mineralogy Mapper — also known as M{+3} and pronounced “M-cubed” — which she helped design in conjunction with the Jet Propulsion Laboratory in Pasadena, Calif. It will look at sunlight bouncing off the lunar surface.

Because certain substances reflect light at specific wavelengths — and the instrument can recognize 260 of them — M{+3} will give scientists a detailed look at the composition of the surface.

As the 1,500-pound spacecraft crosses the poles, Pieters said, there is hope that enough light will scatter to the depths of the craters so M{+3} can detect the presence of water ice. (There are other varieties of ice, but researchers are particular keen on water because life probably can’t evolve without it.)

“Everyone wants to know if there’s water at the poles,” she said. “It’s hypothesized to be there. We know there is hydrogen [one component of water] at the poles, but we don’t know if there’s water at the poles.”

There may not be a frozen pond. But even if they spotted some frost, that would be a welcome discovery.

“That will be one of the first things we will be testing,” she said. “Most people think it’s buried, and if it is, we won’t see it. But we’re going to be looking very hard.”

Finding water with M{+3} would be a bonus for an instrument that has a broader purpose.

As it passes about 60 miles above the lunar terrain, M{+3} will be able to scan the entire surface, using the reflected light to discern details that could offer new insights into the moon’s composition, how it was formed, how our solar system evolved and how planetary systems around other stars might develop.

“The first areas I’m interested in looking at are on the far side of the moon,” said Pieters.

Earlier moon missions revealed that the far side, which cannot be seen from Earth, “has the deepest and largest crater in the solar system, a 2,500-kilometer-wide basin that dominates the whole southern half,” she said. “Because it’s so big, it has clearly been excavated very deep. One of the things that’s going to be thrilling to a geologist, such as myself, is to look inside that hole and identify what’s there.”

Despite the Apollo moon landings from 1969 to 1972, the return of both rocks and soil by U.S. astronauts and other moon missions launched by other countries, scientists don’t know as much as they’d like to about Earth’s companion.

This will be the first detailed global assessment of the moon’s geology, she said.

A complete mineral map will take a month or two. Then the Pieters team of 13 scientists and their support staff will start to zero in on interesting areas.

“We’ve been waiting a long time for this — about 30 years,” she said. “And now it may be a reality. I’m excited.”

gemery@projo.com