Viking 2 data suggests Mars quakes were recorded in 1976

A re-analysis of archival data from the Viking 2 lander suggests that two signals recorded on Mars in 1976 may have been actual marsquakes. The study, published in the journal ‘AGU Advances’, was conducted by a team from Peking University.

For nearly 50 years, the two events recorded during sols 53 and 80 of the mission remained ambiguous due to the instrument's limited sensitivity, data compression, and environmental noise from wind. Because the seismometer was mounted on the lander rather than directly on the ground, distinguishing seismic waves from other vibrations was difficult.

Researchers achieved clarity by comparing the old data with seismic context provided by NASA’s InSight mission (2018–2022). InSight recorded over 1,300 seismic events, nearly 1,000 of which originated from the same region as the signals detected by Viking 2. This suggests the area has remained seismically active over the half-century separating the two missions.