Paul D. Spudis
The Atlantis space shuttle’s planned landing tomorrow marks the historic end of the Space Shuttle program. But it’s also another significant anniversary in space exploration: 42 years ago today, humans first walked on the Moon. Apollo 11 left earth on July 16, 1969, landing on the Moon’s surface on July 20 and returning to Earth four days after that. The final manned mission in the Apollo space program, Apollo 17, was completed in December 1972, making Eugene Cernan the last man to walk on the Moon to date.