What if we're all Martians? The panspermia hypothesis proposes that life didn't start on Earth—it hitched a ride here on Martian meteorites billions of years ago. We examine compelling evidence: while a catastrophic planetary collision sterilized early Earth, Mars remained stable and potentially habitable. Genetic analysis suggests complex life existed on Earth 4.2 billion years ago—suspiciously fast for evolution to happen locally.

Could Mars have been life's original nursery before microbes survived the brutal journey through space on ejected rocks? We explore how organisms might endure radiation and freezing temperatures during interplanetary travel, why scientists remain skeptical, and whether this theory actually solves the origin-of-life puzzle or just moves it to another planet.

The answer could rewrite our understanding of where we truly come from.

Thank you for listening to Bedtime Astronomy — your guide to the cosmos. New episodes on space exploration, NASA missions & the latest astronomy breakthroughs.