About: Apollo 12 Passive Seismic Experiment

The Apollo 12 Passive Seismic Experiment (PSE) was placed on the lunar surface by the Apollo 12 mission as part of the Apollo Lunar Surface Experiments Package (ALSEP). The PSE was designed to detect vibrations and tilting of the lunar surface and measure changes in gravity at the instrument location. The vibrations are due to internal seismic sources (moonquakes) and external (meteoroids and impacts from the spent S-IVB and LM ascent stages). The primary objective of the experiment was to use these data to determine the internal structure, physical state, and tectonic activity of the Moon. The secondary objectives were to determine the number and mass of meteoroids that strike the Moon and record tidal deformations of the lunar surface.