What accounts for life on Earth? I think panspermia is a good bet. To explain the occurrence of life on Earth, an interesting study would be to compare the probability of an Earthly abiogenesis against life arriving here via panspermia from an extraterrestrial abiogenesis. But I'm not sure how to perform the study, other than conducting an opinion survey of credible scientists. Flattering myself here, if I were surveyed I'd vote for panspermia. More of a hunch than anything.
”HM