Comment Re:Millions of years of life-supporting conditions (Score 1) 312
Personally, I think a day/night cycle is needed for life to get started
The convection currents around deep sea volcanic "vents" do the same job. Panspermia and abiogenesis are not mutually exclusive, despite the "either or" argument manufactured by the mass media.
I think panspermia is a long shot, but given the length of time and the size of the universe it's almost certainly happened somewhere at sometime. Volcanos could also be a mechanism for single celled life to leave a planet. It's said that rocks as large as a houses were blasted into obit by Krakatoa and some types of lichen have survived on the outside of the ISS for more than a year. The landing on such an interplanetary flight would be very difficult to survive since the rock is likely to vaporise on impact. Even if it survived and landed on a habitable planet, the locally evolved life forms would more than likely out-compete it by simply eating it.