Today is the 40th anniversary of the launch of Apollo 17 (9:33 pm PST). It remains humanity’s most recent journey to the moon. In my view, that is an astonishingly long lasting lack of interest in sending people to places other than Earth.

Apollo 17 was pretty cool for a couple of reasons. My favourite reason is that it involved the only geologist to visit the moon. Harrison Schmitt was selected in the fourth group of NASA astronauts. Prior to this, all astronauts were required to have extensive experience flying jet aircraft with emphasis on experience as a test-pilot in addition to a bachelors degree (for Apollo it had to be an engineering degree). Realizing this substantially limited the scientific expertise in the astronaut pool NASA changed up the application requirements: no flight experience needed but doctorate degrees required. The idea being to train scientists as pilots instead of training pilots to be scientists. They now had a group of six scientists: three physicists, two physicians, and a geologist.

Schmitt had to spend his first year in the astronaught corps getting up to speed as a jet pilot. When he began more specific Apollo training he took an active roll in remoulding the geology courses that were being taught to all the pilot-engineers. He turned the field school on its head in time for the first science-primary lunar mission, Apollo 15, where he served on the back-up crew. Arguably as a result of his influence, the Apollo 15 crew took charge of their “geologist” responsibilities and weighed in on strategic matters that could affect the quality of science done on the moon. Apollo 15 subsequently found a chunk of anorthosite that was later labeled the “genesis rock” – it is one of the oldest intact specimens of rock ever analyzed by humans. And these are just a few of the impacts Schmitt had before he flew into space.

Blue Marble
credit: NASA

40 years ago today Schmitt launched into space on board Apollo 17 with Gene Cernan and Ron Evans. While en-route to the moon Schmitt took the above photo often named “the blue marble”. Schmitt and Cernan landed on the lunar surface after four and a half days of hurtling through space. As Cernan exited the lander first, and Schmitt followed a few minutes later, Harrison Schmitt has the distinction of being the last person to arrive on the moon. On their final moon walk, he spotted a piece of rock that seemed out of place to him. It has since been branded by NASA as the most interesting sample returned from the moon. It seems noteworthy that it was collected by the only geologist to go to the moon. Its origin and age remain unknown.

Troctolite 76535
credit: NASA

They also set off some large explosions to facilitate gravimetric and seismic measurements. Space explosions are gnarly.

At the end of their mission, Schmitt re-entered the lander first. Cernan followed shortly thereafter making Cernan the last person to leave the moon. (The two apparently have a friendly argument about which is more significant: last to arrive or last to leave.) As he climbed aboard the lunar lander, Cernan spoke what I suspect are the second most famous set of “moon words.”

“And, as we leave the Moon at Taurus–Littrow, we leave as we came and, God willing, as we shall return, with peace and hope for all mankind.”

Apollo 17 landing site as seen by the Lunar Reconnaissance Orbiter in 2011
credit: NASA/BBC