Astronomers believe they have found the lunar module from the Apollo 10 mission five decades after it was released into space by the crew.
The module, measuring just four metres wide, was nicknamed Snoopy and was believed to have been lost forever in 900 million kilometres of space after it was jettisoned.
Snoopy, named after the cartoon dog, was used as a practice run for the Apollo 11 lunar landing, to take place two months after Apollo 10 in July 1969.
Two of the three astronauts transferred into it to fly above the Moon's surface.
They then returned to the command module. After demonstrating the docking manoeuvre, the mission was over and Snoopy was shot off into space.
Nick Howes, a fellow of the Royal Astronomical Society, said he is certain it has been found and all they need is someone to go and retrieve it.
Howes said he began the search for the module in 2011 and calculated the odds of finding it were 235 million to one.
He and a team of astronomers analysed terabytes of radar data and in 2018 found what they believe is Snoopy.
"We are 98 per cent convinced we have found it ...Until someone gets really close to it and gets a detailed radar profile, we can't be sure," Howes said.
He said it would be a "really fantastic achievement for science" if the capsule was retrieved.
"As a piece of history, a moment in history, this is a unique artefact."
Howes said someone with space expertise such as SpaceX founder Elon Musk would be the ideal candidate to bring Snoopy back to Earth.
"I would love to get Elon Musk and his wonderful spacecraft up and grab it and bring it down.
"As Apollo 10 crew member Eugene Cernan said to me, 'Son, if you find that and bring it down, imagine the queues at the Smithsonian?'.
