The moon is much more seismically active than we realized, a new study shows. A reanalysis of abandoned data from NASA's Apollo missions has uncovered more than 22,000 previously unknown moonquakes — nearly tripling the total number of known seismic events on the moon.
The findings were presented at the Lunar and Planetary Science Conference, which was held in Texas between March 13 and March 17, and are in review by the Journal of Geophysical Research. Apollo astronauts deployed two types of seismometers on the lunar surface: one capable of capturing the 3D motion of seismic waves over long periods; and another that recorded more rapid shaking over short periods.
"Literally no one checked all of the short-period data before," study author Keisuke Onodera, a seismologist at the University of Tokyo, told Science Magazine.