Posted on behalf of Roberta Kwok
Scientists are using temperature measurements to map the rockiest parts of the Moon – and the results could help NASA choose better landing sites for missions.
Infrared radiation readings taken by the Diviner Lunar Radiometer Experiment, an instrument on NASA’s Lunar Reconnaissance Orbiter (LRO) mission, have enabled researchers to see the moon’s temperature variations in detail. Not surprisingly, the surface heats up during the day and cools down at night. But rocks tend to retain their heat longer than the regolith, or lunar soil, and so they stay warm throughout the night.
Mapping these hot spots has provided a quick and quantitative way to assess rock abundance over vast areas of the Moon, says planetary scientist Josh Bandfield of the University of Washington in Seattle, who presented his results on Thursday at the Lunar Science Forum, held at NASA Ames Research Center in Moffett Field, California. It’s a faster method than counting rocks one by one in the high-resolution images provided by LRO. Mission planners could use the resulting rock abundance maps to pick landing sites that don’t present too many rock risks – but have enough rocks nearby for interesting geological research.
Because rocks get worn away over time, older craters tend to be less rocky. But a young crater like Tycho “just lights up” on the rock abundance map, says Bandfield (see image).
The Diviner team has also mapped spots that are cold enough to retain water ice. Around the Moon’s south pole, the surfaces of crater floors fulfill this criteria – but there are even larger surrounding areas where water ice would be stable below the surface, said planetary scientist David Paige of the University of California, Los Angeles at the forum. These regions might warm up during the hottest part of the year, but the subsurface would stay cool enough to preserve water ice for billions of years, he said.