US astronaut Edgar Mitchell, who was the sixth man to walk on the Moon, has died aged 85.
Captain Mitchell passed away at a hospice in West Palm Beach, Florida, one day before the 45th anniversary of his Moon landing, his family said.
As part of the Apollo 14 mission in 1971, he spent more than nine hours on the Moon conducting experiments.
He said he had undergone an epiphany in space and in later life revealed a belief that aliens had visited Earth.
Mitchell's mission to the Moon was the fourth in the US Apollo series, and the first to follow the ill-fated Apollo 13 which aborted its attempt to land after an oxygen tank explosion.
Mitchell and his crewmate, another Navy officer, Captain Alan Shepard, made it safely to the lunar surface. Their landing site was the Fra Mauro Highlands, a hilly area that was the target of the failed Apollo 13 mission.
During their 33 hours at the site, the two astronauts collected 45kg (94lb) of Moonrock for examination back on earth and completed the longest moonwalk in history.