New Moonquakes from Old Data

Editors’ Highlights are summaries of recent papers by AGU’s journal editors.

Source: Journal of Geophysical Research: Planets

The Apollo missions to the Moon, famous for having brought astronauts to our natural satellite, also deployed a variety of geophysical instruments. Among them, long-period and short-period seismometers collected data until the last was turned off in 1977. With the exception of the short-lived Chandrayyan-3 lander, these are still the only seismograms obtained on the Moon.

Taking advantage of a recently released seismic data archive with systematic error correction and data homogenization, Onodera [2024] doubled the number of seismic events recognized in the Apollo data. The increase is particularly significant for shallow moonquakes, the most energetic of these events. Onodera [2024] adds 46 events to the previously known 28. The magnitude-frequency relationship in this new catalog suggests that it is fairly complete, making it possible to reexamine the origin of this seismic activity. Moonquakes no longer appear correlated with Earth-Moon distance, tropical month, or shallow faults, but more probably with deeper stress sources in the Moon’s northern hemisphere.

The uptick in lunar seismic data reanalysis heralds a new era in planetary data collection. Mission design increasingly appreciates the value of in-situ geophysical techniques, and the recently concluded InSight mission to Mars demonstrated the potential of collecting seismic data, even from a single instrument. Upcoming projects that feature seismometers and related instruments include Farside Seismic Suite, Lunar Environmental Monitoring, and Chang’e 7 and Chang’e 8, many of which are scheduled for launch in 2026. Additional capabilities are being developed. If 50-year-old Apollo data still contains information that leads us to rethink the Moon’s activity, the flotilla of geophysical instruments to be launched in the coming years is sure to revolutionize our understanding of the Moon.

Citation: Onodera, K. (2024). New views of lunar seismicity brought by analysis of newly discovered moonquakes in Apollo short-period seismic data. Journal of Geophysical Research: Planets, 129, e2023JE008153. https://doi.org/10.1029/2023JE008153

—Laurent G. J. Montési, Former Editor-in-Chief, JGR: Planets

Text © 2024. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Related