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Moon Elements

July 30, 2009

A listener asks: What is the moon made of?


Moon rocks revealed. I’m Bob Hirshon and this is Science Update.

Listener Joel Haglund wrote to ask what the moon is made of. We turned to Noah Petro, a lunar geologist at the NASA Goddard Space Flight Center. He says about four and a half billion years ago, an object the size of Mars struck the earth, ejecting into orbit materials that melted together to form the moon. He says since it came into existence so early in earth’s history, the mineral composition of the moon is relatively simple.

NOAH PETRO (NASA Goddard Space Flight Center):
The bright materials you see when you look at the moon are thought to be mostly made of anorthocyte, which is a common mineral on the earth and then the dark areas on the moon are made up of volcanic basalts, much like you see in Hawaii, or Iceland for instance.

Petro adds that the interior of the moon probably contains more iron-bearing minerals than the surface. I’m Bob Hirshon, for AAAS, the science society.