It seems to me the main thing that gave panspermia a boost in recent years is the discovery that:
1. There is far more life on earth that reside deep underground in cracks and cavities in rocks than we realized just 20-30 years ago. Prior to 1980s, the conception of life on earth is the sun is the ultimate power source of all the chemical energy life on earth uses, and vast majority of life on earth must be residing at, above or just barely below its solid surface. We now thing up to half of all of the earth's biomass resides deep underground and may be largely independent of any chemical process Drive by the sun. These life are often extremely frugal of available resources and may wake up for major biochemical events on the order of once every many years. So Life that lives deep underground seems far more capable of surviving an meteoric impact on its origin world, long trips through interstellar distances encased in rock fragments, and then revive on a wide range of destination environments.
2. The different bodies in the solar system exchanged far more material through ejecta from meteoritic impacts then we realized. The total amount of debris from meteoric impacts exchanged between inner planets may be many thousands of cubic miles.
So it becomes plausible if life originate on one body in the solar system, then sizeable volumes of live specimens may have been distributed to major bodies over the life of the solar system.
1. There is far more life on earth that reside deep underground in cracks and cavities in rocks than we realized just 20-30 years ago. Prior to 1980s, the conception of life on earth is the sun is the ultimate power source of all the chemical energy life on earth uses, and vast majority of life on earth must be residing at, above or just barely below its solid surface. We now thing up to half of all of the earth's biomass resides deep underground and may be largely independent of any chemical process Drive by the sun. These life are often extremely frugal of available resources and may wake up for major biochemical events on the order of once every many years. So Life that lives deep underground seems far more capable of surviving an meteoric impact on its origin world, long trips through interstellar distances encased in rock fragments, and then revive on a wide range of destination environments.
2. The different bodies in the solar system exchanged far more material through ejecta from meteoritic impacts then we realized. The total amount of debris from meteoric impacts exchanged between inner planets may be many thousands of cubic miles.
So it becomes plausible if life originate on one body in the solar system, then sizeable volumes of live specimens may have been distributed to major bodies over the life of the solar system.
