A professor from Cardiff University, Chandra Wickramasinghe, has made the claim that life on Earth was likely brought here from somewhere else some 3.8 billion years ago. Panspermia, or life being seeded on Earth from other planets, has once again made its way into the news as Wickramasinghe’s claim fleshes out.
According to Wickramasinghe’s theory, life will occasionally be carried with comets as they travel through space, multiplying within their frozen bodies and then releasing these microbes on the planet as the comets either smash into them or pass in close orbit.
Of course Wickramasinghe’s theory doesn’t explain how life begins in the first place. It’s essentially answering the, “Which came first the chicken or the egg” question with, “The chicken, but only because it hatched from a different egg.” He does, however, suggest that there is no hard evidence to support the current theory of the origin of life on this planet, that of a mysterious primordial soup from which all life was evolved over the course of several billion years.
He suggests that interstellar clouds, massive areas of dust and material in the Milky Way galaxy are the result of life being broken down into dead dust rather than being built up into a sort of “cradle of life.” Earth, according to this theory, is only a tiny speck in an ever growing life seeding process that now spans a considerable volume of the Galaxy, though how many planets life actually survives on is arguable. Still, it is a theory based in hard science and it’s giving many scientists’ theory of primordial origin a run for their money.
Professor Wickramasinghe and his colleague, the now deceased Sir Fred Hoyle, first proposed the theory of pan-spermia in the 1960’s amid a considerable amount of controversy and excitement. The theory has never been disproved, but was somewhat lacking in conclusive proven evidence at the time, but the professor says the evidence has only continued to mount since then.
What would it mean for life on our planet if it turned out to have come from elsewhere in the stars? For one thing, it would finally prove once and for all that life elsewhere in the universe did indeed exist. Of course though this discovery -if proven- would turn out to be one of the greatest of all time, it would still leave the question “Then where did the elsewhere life come from?” And given the scope, size, and age of the universe, that question would be incredibly difficult to answer. It would in fact, be even more difficult to explain than had the origin of life merely been on our own planet dealing with forces we understand and interact with every day.
There is one other thing this theory would suggest. If life is seeded over vast distances, then it also suggests vast amounts of time are being used and on various planets similar to ours. So if human life evolved over the course of a few hundred billion years, what would another planet given a hundred million year head start be like?