I am not "dismissing" this idea or the possibility. I am only saying that the simplest explanation is usually the best explanation, unless there is any evidence against the simpler explanation. Why consider the more complicated potential possibilities first? There is no point in that, even though there are so very many possibilities. And, of course, we know that there is life far down in the lithosphere of Earth, due to deep drilling samples we have seen. These samples of bacteria are embedded in rock formations, quite deep. It is quite interesting that microorganisms can be found in the lithosphere up to 5 kilometers below the surface. So, is it possible that a large chunk of rock could be blasted away from Earth by an asteroid strike? Yes, possible. However, it might be more interesting to investigate how life originates from existing conditions on Earth, billions of years ago. EVEN IF we were to agree that life on Earth came from some other star system, many light-years away, carried on interstellar dust or inside rock blown out from some faraway star system, then this does not really explain the chemical processes of the origin of life. By the way: Just how long would it require from a chunk of rock to travel 50 light-years, anyway? If the rock left at over escape velocity, from Earth, at maybe 20 km/second, then we are looking at about a million years. But, how many planets with life exist within a 50-light-year radius? Anyway, I think we must re-evaluate the statistical probability for life, other than life on Earth, existing elsewhere in our own galaxy. For these reasons: It is always best, in science, to go with the simplest conditions that satisfy some observation. In this case, the observation that life evolved here on Earth. One cannot entirely dismiss ANYTHING, of course.
