Crystal analysis pushes the moon’s age back 40 million years

Analysis of zircon crystals brought back by Apollo astronauts in 1972 suggests the moon is 40 million years older than previously thought. The study, carried out by researchers at the University of Chicago in the US, is the first to use atom probe tomography (APT) to calculate the age of the zircon crystals.

Zircon readily incorporates uranium and excludes lead from crystal lattices and is structurally resistant to post-crystallisation thermal alteration. This means that any lead in the samples has come from the radioactive decay of uranium atoms. By measuring the ratio of the two elements, the researchers could calculate when the zircon crystals must have originally formed.