NASA scientists have discovered the cause of some small tremors, or moonquakes, on the lunar surface: the remnants of a spacecraft that was left there 50 years ago.
When the Apollo 17 astronauts returned to Earth, in 1972, they left the mission’s landing craft behind. The moon’s temperatures, which swing from hot to cold, could be causing metal in the lander to swell and shrink. This has been producing ground vibrations that are picked up by NASA’s sensors. The scientists learned this from examining 50-year-old data.
The information could be useful if space agencies build bases on the moon for future missions. Scientists will need to account for how the moon’s extreme temperatures might affect the buildings and instruments they install.