The scientific legacy of Apollo

This December marks 40 years since Gene Cernan and Harrison “Jack” Schmitt of Apollo 17 left the lunar surface and returned safely to Earth. This anniversary has been given additional poignancy by the death earlier this year of Neil Armstrong, the first man to set foot on the Moon with Apollo 11 in July 1969. The history of the Apollo project, and its geopolitical motivation within the context of the Cold War, is well documented (e.g. Chaiken 1994, Burrows 1998, Orloff and Harland 2006) and need not be repeated here. However, although the scientific legacy of Apollo has also been well-documented (e.g. Heiken et al. 1991, Wilhelms 1993, Beattie 2001), and is generally well-known within the lunar science community, I have found that it is still underappreciated by many astronomers, and even by some planetary scientists who are not directly involved in lunar studies. Hence this brief review of Apollo science. In the three-and-a-half years between Armstrong’s first “small step” in 1969 and the departure of Cernan and Schmitt from the Taurus-Littrow Valley (figure 1) in 1972, 12 astronauts explored the lunar surface at the six Apollo landing sites (figure 2). The total cumulative time spent on the lunar surface was 12.5 days, with just 3.4 days of that spent outside the lunar modules (Orloff and Harland 2006). Yet during this all-too-brief time, samples were collected, measurements made and instruments deployed that have revolutionized lunar and planetary science and which continue to have a major scientific impact today.