# As Mars’s atmosphere thinned and its surface became cold, dry and irradiated billions of years ago, any surviving microbial life may have found its last refuge underground. Yet the environments most capable of sheltering life could lie metres—or kilometre

> **Open Intelligence Dossier** · First detected: 2026-07-25 04:07 UTC · Category: Science

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*Canonical Source: https://pulse.byoviral.com/trend/2026-07-25/as-mars-s-atmosphere-thinned-and-its-surface-became-cold-dry-and-irradiated*