july: surveyor 3 & apollo 12
Before the Apollo missions, NASA sent a series of Surveyor probes to the Moon to examine potential landing sites. Apollo 12, the second manned landing, touched down extremely close to Surveyor 3.
The astronauts recovered photographic equipment from the probe and returned it to Earth. Scientists were stunned to discover bacteria in the equipment, probably deposited by a technician who sneezed, which had survived three years on the Moon in total vacuum and under heavy bombardment with cosmic rays.
Image: NASA.