The moon may carry material produced by life from Earth dating back to when plants first filled the planet’s air with oxygen, according to study of data from a Japanese lunar orbiter. A team led by Kentaro Terada of Osaka University looked at data from the Selenological and Engineering Explorer, better known as Kaguya. The researchers found that a certain kind of oxygen isotope was present in the lunar soil, an isotope that occurs on Earth.
Almost all of the oxygen in Earth’s atmosphere for the last 2 and a half billion years came from photosynthesis. That means the moon’s rocks have been picking up small amounts of oxygen from living things on Earth; the moon is “contaminated” with the waste products of plants, the researchers said. Read more.