Apollo 11 set up the Moon's first seismometer in 1969; its recorded moonquakes gave scientists the first detailed map of the lunar interior

When Neil Armstrong and Buzz Aldrin stepped onto the Sea of Tranquility in July 1969, they deployed several scientific instruments during their moonwalk, including one designed not to study rocks or footprints but to detect seismic activity on the Moon. It was a seismometer, the first instrument placed on another world to detect the equivalent of earthquakes.

Raccontata datimesofindia.indiatimes.com