Exploring the Moon
A history of lunar discovery from the first
space probes to recent times
The waning crescent Moon.
Repeating the feat
A second Apollo mission also beat President Kennedy’s deadline for landing a man on the Moon by the end of the decade. Apollo 12
touched down in Oceanus Procellarum only a short walk from the Surveyor 3 robot probe that had landed two and a half years earlier. Given that Apollo 11
had overshot its intended landing site by about three miles, Apollo 12’s precision landing was an impressive piece of targeting.
Astronauts Charles Conrad and Alan
Bean made two Moonwalks, setting up scientific instruments and examining the
long-dead Surveyor. Pictures of Conrad next to Surveyor 3 are among the most memorable of the Apollo programme. A number of parts from
the probe, including the TV camera and soil-sampling arm, were brought back to
Earth. Terrestrial microorganisms were found on the camera. At first these were
thought to have been there since its launch and survived the harsh conditions
on the Moon, but it is now thought likely that the camera was contaminated after its return to Earth.
Making a grab – Conrad reaches for Surveyor 3’s camera
Apollo 12’s rocks turned out to be around 3.2 billion years old, making this the youngest
of the Apollo landing sites. This age difference from the Apollo 11 site, added
to slight differences in composition from those previous samples, demonstrated
that there had been several episodes of volcanic flooding on the Moon, and also
different sources of lava within its interior. The geological history of the
Moon was becoming more complex than previously imagined.
After these two successful landings, disaster struck. Apollo 13’s landing was cancelled when an oxygen tank in the Service Module exploded on
the way to the Moon. Unable to turn back, the astronauts had no option but to
continue towards the Moon and let its gravity swing them behind it and back to
Earth. All future Service Modules were modified to prevent a repeat of the
accident that nearly cost the crew their lives. The story of the mission was
subsequently recreated in a feature film, Apollo 13.
Flights resumed in early 1971 with Apollo
14, commanded by Alan Shepard, America’s first man in space, flying for a second time after a gap of nearly 10 years.
This mission was sent to the site intended for Apollo 13, the hilly formation
called Fra Mauro, which was believed to consist of ejecta from the impact that
formed the Mare Imbrium basin. The rocks were much lighter-coloured and
different in composition from the dark lavas of the lowlands collected by
Apollos 11 and 12. They proved to be 3,900 million years old, which is when the
Imbrium basin was formed.
Apollo 14 commander Alan Shepard surveys the scene
At the end of his Moon walks, Shepard, a keen golfer, achieved a sporting “first” when he produced a gold ball from his spacesuit pocket, dropped it on the
surface and took a swing at it with the handle of a sampling device fitted with
the head of a six iron (he needed three attempts to connect properly). His
colleague Ed Mitchell responded by making an impromptu javelin throw with a rod
from the solar wind collector. Both the golf ball and the javelin ended up in a small crater nearby.