The age of the Earth’s crust is contentious, and geologic material available for analysis is few and far between. In a new study in Nature Geoscience, NAI-funded astrobiologists have mapped the distribution of radiogenic isotopes within an ancient zircon from the Jack Hills in Western Australia (a site with some of Earth’s oldest rocks). Their results confirm that Earth’s oldest known continental crust formed just after the Earth–Moon system.

These oxygen isotope ratios from within such zircons have been used to infer when the conditions habitable to life were established.