Moon’s rough 'wrinkles' can reveal its age

Like wrinkles on the skin, the roughness of craters and other features on the Moon’s surface can reveal its age, according to a new study.

To come to the conclusion, Meg Rosenburg and her colleagues at the California Institute of Technology, Pasadena, California put together the first comprehensive set of maps revealing the slopes and roughness of the Moon’s surface.

These maps are based on detailed data collected by the Lunar Orbiter Laser Altimeter (LOLA) on NASA’s Lunar Reconnaissance Orbiter.

"The key is to look at the roughness at both long and short scales," said Rosenburg, the first author of the study.

"Old and young craters have different roughness properties -- they are rougher on some scales and smoother on others," he said.

That’s because the older craters have been pummeled for eons by meteorites that pit and mar the site of the original impact, changing the original shape of the crater.

"Because this softening of the terrain hasn’t happened at the new impact sites, the youngest craters immediately stand out," said NASA Goddard's Gregory Neumann, a co-investigator on LOLA.

"It is remarkable that the Moon exhibits a great range of topographic character: on the extremes, surfaces roughened by the accumulation of craters over billions of years can be near regions smoothed and resurfaced by more recent mare volcanism," said Oded Aharonson, Rosenburg’s advisor at the California Institute of Technology.

By looking at where and how the roughness changes, the researchers can get important clues about the processes that shaped the Moon.

The study was published in the Journal of Geophysical Research earlier this year.