panspermia

The idea that life can travel through space from one planet to another, perhaps carried by rocks or dust.

Panspermia is a hypothesis, not a proven explanation for how life began. It suggests that life, or material that could develop into life, may have moved naturally between worlds; it does not explain where life first originated. A less common version, directed panspermia, proposes that life was deliberately sent between planets.

• The meteorite made us wonder whether panspermia could explain how life reached Earth.
• Researchers are testing whether microbes could survive the journey that panspermia proposes.
• Even if panspermia is possible, it does not tell us how life first began.