Mark I. Vuletic

Last updated 21 March 2008

Background

The panspermia hypothesis is the hypothesis that the first organisms on Earth came into existence elsewhere in the universe and were transported to the Earth by natural means, for instance by hitching a ride on a comet or meteor.

Analysis

While it is true that panspermia pushes back the question of how life came into existence in the first place, this does not make the hypothesis completely useless. If there are any problems for the origin of life that are particular to the Earth, such as its early atmosphere, these problems would be bypassed by panspermia. That would be far from showing that life did arise by natural processes elsewhere in the universe, but it would open up a wider range of possible mechanisms to explore.

However, the main reason panspermia is not taken very seriously by modern origin of life researchers is that it is premature: there is at this time no real reason to believe that the origin of life did not take place on Earth. However, there are origin of life researchers who take very seriously the idea that a signficant amount of prebiotic synthesis took place in outer space, and that the resultant chemicals important to abiogenesis were delivered to the Earth by means meteorites or comets. Since important prebiotic chemicals have indeed been detected in space and on meteorites, such proposals are not far-fetched, though their ultimate plausibility is still debated.