AIUI most panspermia theories don't posit either of those - definitely not that life originated in space, and not necessarily that it only originated once. The most common variants seem to be that life originates in gravity wells, is ejected by major impact events, drifts through space and eventually re-enters other gravity wells. Simulations suggest that bacteria can potentially survive all of these.
AIUI most panspermia theories don't posit either of those - definitely not that life originated in space, and not necessarily that it only originated once. The most common variants seem to be that life originates in gravity wells, is ejected by major impact events, drifts through space and eventually re-enters other gravity wells. Simulations suggest that bacteria can potentially survive all of these.