How many times did life originate on Earth?
Maybe it's even zero.
For all we know pansphermia brought life here from Mars or somewhere else . It's humbling how we know so little about life's origins and life's possibilities elsewhere after 50+ years of the Space Age and over a Trillion dollars spent by mankind exploring space. Who in say 1960 would have predicted our continued utter ignorance on the facts of the matter of life in outer space a decade into the 21st Century? Not I.