Kevin Keogh

If microbial life started on Earth, it must have since spread and must continue to spread elsewhere in the solar system simply because it clearly has had both the time and the capability to do so. What could possibly sterilized all the trillions of Earthly microbe that have been launched outside the Earth's gravity well over the last 4+ billion years? I suppose other terrestrial bodies may have their own competitors, but microbial life on Earth is clearly well adapted to both space transport and subsurface survival elsewhere. Why would this be so were Earth the only habitat it had ever encountered? What makes life assembling itself from non-life in any specific location "simpler" than life arriving from another location? Don't we assume that all current life on Earth comes from previous life on Earth? So why stop this logical chain of reason at the Earth? Why assume the Earth is a closed system vis a vis the transfer of microbial life when it is clearly anything but? Once a self-replicating chemical system capable of interplanetary travel evolves, what stops it from colonizing nearby terrestrial bodies? Microbes don't need the sun, gravity, low radiation, or any environmental aspect unique to Earth. So why assume they are must be native to Earth when they obviously could have from elsewhere? Again, if we found a colony of microbes on the Moon, or the Space Station would it be "simpler" to assume that their first primordial ancestors evolved here or there?

Unfortunately, this bizarrely close-minded opinion is all too prevalent among scientists. "Until the old way I learned this long before a lot of new evidence was discovered is totally disproven, I am simply not interested in weighing any new evidence objectively." Nobody has ever come close to creating life on earth. Nobody understands the the mechanisms that could create life on Earth. However, viable microbes could easily have arrived on Earth from elsewhere by known and well-demonstrated mechanisms. I cannot fathom why so many scientists imagine the manner in which we know for certain things work on Earth (life always comes from previous life) somehow defies Occam's Razor when the concept is expanded to include extraterrestrial environments. Is this simply a pre-Copernican mentality that Earthly biochemical processes must be uniquely complex compared to those that exist in the rest of the universe? I mean, if you found a colony of microbes on living on the Space Station or the Moon, would you simply assume that they spontaneously assembled themselves there until it was proven otherwise?