Panspermia

From the 1970s, Wickramasinghe and Hoyle developed a modern version of panspermia: the proposal that comets and other cosmic material can transport microorganisms or precursors of life between worlds.

Astrobiology legitimately studies organic molecules, habitability, and whether material can travel between planets. Stronger claims that extraterrestrial organisms explain the origin of terrestrial life or particular disease outbreaks require evidence beyond the existence of organic material in space and remain disputed.