Uranium isotopes in ancient grains indicate early Earth was less hellish than textbook descriptions

Cathodoluminescence image of a Hadean zircon crystal from the Jack Hills conglomerate, similar to the ones studied in this work

Source: © Elizabeth Bell

Mass spectrometry technique that works on tiny samples refines understanding of Earth’s first geologic eon

There is no evidence that natural nuclear fission reactors were widespread on the early Earth. Earth’s crust was actually more like it is today than previously thought. So say researchers who have developed a new analytical procedure to measure uranium isotope levels in tiny crystal structures that are over 4 billion years old.