São Paulo’s Cratera de Colônia Confirmed as Asteroid Impact Site

Researchers from the University of São Paulo (USP) and the Institute of Environmental Research analyzed zircon grains collected from the Cratera de Colônia in Parelheiros, São Paulo. The samples, obtained during three Sabesp drilling campaigns originally intended to locate groundwater, yielded 40 grains that were examined under a microscope. Six grains showed planar deformation features (PDFs) and other shock‑induced alterations, signatures that form only under the extreme pressures and temperatures of a large impact.

The findings, published in the journal *Earth and Planetary Science*, strengthen the hypothesis that the 3.6‑km‑wide crater was created by an asteroid collision millions of years ago, rather than by tectonic processes. Lead author Victor Velázquez Fernandez described the PDFs as a “fingerprint” of such impacts, confirming the crater’s extraterrestrial origin.