by Todd Jackson

The Moon rocks brought back from the Apollo missions are in the news thanks to the return, to an Alaska museum, of a piece of rock from the Apollo 11 mission that had been missing since 1973.

The study of the Moon rocks has yielded significant new knowledge, including these three facts:

1) Moon Rock has in its makeup neither life nor water. There is no sandstone, no limestone, and no shale, the making of which requires water in some way-whether that be sedimentation or absorbing lime from the shells of sea creatures. There is no life, nor evidence that there ever was life, in Moon rock. All Moon rocks were formed through means related to pressure.

2) Moon rocks are enormously old, so old that the youngest we have from the Apollo missions is are close to as old as the very oldest stones we have found on Earth. Earth, with its winds, water whether in the form of rain or tsunami surges, and above all its volcanism, is a tremendously corrosive place to persist if you’re a rock, certainly compared to the Moon. The Moon is an environment where old things typically stay preserved and, typically, new things never happen at all.

3) And yet we know that the Moon was not some alien planet that one day wandered too close, but was made from the same body or material pool as the Earth. This is evident from their having the same oxygen isotopic signature-in other words, we know this from the Moon rocks. We know this even though the distribution of metals and other elements is different in the two groups of rocks.

Most other Apollo missions were ambitious about geological work than Apollo 11, and collected more rocks. For geologic exploration, the prize certainly goes to Apollo 17, the final mission and, so far, the last time humans set foot on the Moon. The Apollo 17 crew collected 243 pounds of Moon rock, over ten times what Apollo 11 collected. Harrison Schmitt was the only trained scientist to visit the Moon, and Gene Cernan had been trained exhaustively in geology and had become an acute field observer in his own right. Apollo 17’s astronauts went beyond merely collecting from the surface and performed a core drill into the regolith, as well as taking over two thousand on site photographs.

Of course, the glamour of Apollo 11, as the first mission to actually have a human set foot on the Moon, gives its samples a special value apart from their scientific interest.

When Apollo astronaut Neil Armstrong stepped on the Moon in July 1969 and uttered the words “We came in peace for all mankind,” President Richard Nixon apparently took his words to heart. He arranged to have pieces of Moon rock distributed to every state in the country, and every country on Earth, mounted on a commemorative plaque.

The rock that was given to Alaska disappeared after a fire in 1973. Alaska thus joined a list of Moon rock recipients who lost their stones, a list that includes Ireland, Nicaragua, and the Isle of Malta. The Alaska rock reappeared in an obscure warehouse in Minnesota. It is still unknown how it came to its location, how long it had been there, or how it was removed from the fire, which was determined to have been caused by an arsonist.