Radar Images Challenge Notion of Ice on the Moon

ITHACA, N.Y. — Detailed radar images offer no evidence of ice on the moon, data that appear to contradict scientists’ earlier conclusions, say astronomers at Cornell University’s Arecibo Observatory.

In December, Defense Department scientists said radar signals collected by the unmanned Clementine spacecraft in 1994 suggested ice deposits in deep craters in the permanently dark regions at the moon’s south pole. The journal Science reported their findings.

But the Cornell scientists say in an article in this week’s Science that Clementine probably saw “very rough surfaces associated with the steep slopes of impact craters.”

“We don’t see anything that suggests ice,” Cornell astronomy professor Donald B. Campbell said Thursday.

Campbell said observations taken at Arecibo in Puerto Rico in 1992 found that the areas spotted by Clementine in the permanently dark region also existed in the sunlit part of the moon and near the equator.

Arecibo, operated by Cornell’s National Astronomy and Ionosphere Center for the National Science Foundation, is the world’s largest single dish radio telescope. At Arecibo, scientists were able to study the moon’s polar region with greater resolution than that used in the Clementine studies, Campbell said.

But until scientists study the entire surface of the moon, the possibility remains of ice deposits in the bottoms of deep craters, he said.

The implications of ice on the moon would be profound on humanity’s future lunar exploration. The ice could be mined and the water split into oxygen and hydrogen, which is a basic rocket fuel. It would be like having a filling station on the moon.