The first Chinese mission to softly land on the moon’s surface has discovered a new kind of volcanic moon rock.
In December 2013 China’s Chang’e 3 lander mission touched down on a smooth flood basalt plain next to a relatively fresh impact crater (now officially named the Zi Wei crater) that had conveniently excavated bedrock from below the regolith for the Yutu rover to study.
Because Chang’e-3 landed on a comparatively young lava flow, the regolith layer was thin and not mixed with debris from elsewhere. Thus it closely resembled the composition of the underlying volcanic bedrock. This characteristic made the landing site an ideal location to compare in situ analysis with compositional information detected by orbiting satellites.
Washington University’s Bradley L. Jolliff said, “We now have ‘ground truth’ for our remote sensing, a well-characterized sample in a key location. We see the same signal from orbit in other places, so we now know that those other places probably have similar basalts.”
The basalts at the Chang’e-3 landing site also turned out to be unlike any returned by the Apollo and Luna sample return missions.
The diversity tells that the Moon’s upper mantle is much less uniform in composition than Earth’s and correlating chemistry with age, researhers can see how the Moon’s volcanism changed over time, noted Jolliff.
The study is published in the journal Nature Communications Dec. 22.