1969

Second on the Moon

Charles “Pete” Conrad (1930–1999), Alan Bean (1932–2018), Richard Gordon (1929–2017)

Just four months after the successful voyage of Apollo 11, NASA astronauts were once again walking on the Moon. On November 19, 1969, astronauts Alan Bean and Charles “Pete” Conrad targeted the lunar module Intrepid toward a precision landing near NASA’s 1967 Surveyor 3 robotic lander, while command module pilot Richard Gordon circled high above. Conrad and Bean were able to successfully demonstrate pinpoint landing accuracy by setting their spacecraft down within 600 feet (180 meters) of Surveyor 3. Such accurate landings would be critical to future Apollo missions.

Conrad and Bean spent about 32 hours on the Moon, nearly a quarter of which was spent outside, taking samples and setting up experiments in the flat lava plains of Oceanus Procellarum (Ocean of Storms). Their longest excursion consisted of a walk to the Surveyor 3 probe, where they took off some pieces and instruments to return to the Earth. Surveyor 3 had been sitting on the lunar surface for more than three years; the returned parts provided detailed information on the long-term effects of vacuum, intense sunlight, and micrometeorite impacts on lunar surface equipment. Amazingly, there were even some dormant bacteria on some of the surfaces that had somehow made the trip to the Moon (and back) and that some tests showed still remained viable, even after three years in the Moon’s harsh vacuum and ultraviolet (UV) environment.

The longer duration on the surface let the Apollo 12 astronauts collect about 75 pounds (34 kilograms) of lunar samples (compared to 48 pounds [22 kilograms] from Apollo 11), including soils, small rocks, pieces of boulders, and impact crater deposits. Scientists analyzing those samples discovered that the Procellarum basin’s dark volcanic rocks are much younger (3.1–3.3 billion years old) than those returned by the Apollo 11 crew from the Tranquillitatis basin (3.6–3.9 billion years old), indicating that the Moon was volcanically active for at least the first 1.3–1.5 billion years of its history. The Apollo 12 samples also contain different rock chemistries from those seen in Tranquillitatis, including dark glassy rocks, and the first samples of a new class of lunar rock made out of jumbled, impact-melted, and welded-together rocky fragments known as a breccia.

Astronaut Alan Bean setting up part of a scientific experiment package on the plains of Oceanus Procellarum (Ocean of Storms) during the Apollo 12 mission in November 1969. The photo was taken by Bean’s fellow astronaut Pete Conrad, whose shadow is in the foreground.