Rare oxygen isotope detected at last — and it defies expectations

Physicists have for the first time detected oxygen-28 — an isotope of oxygen that has 12 extra neutrons packed into its nucleus. Scientists have long predicted that this isotope is unusually stable. But initial observations of the ²⁸O nucleus suggest that this isn’t the case: it disintegrates rapidly after creation. If the results can be replicated, physicists might need to update theories of how atomic nuclei are structured.