Abstract
Philosophers and others have been fascinated by the question of extraterrestrial life for centuries, but exobiology has never really taken off as serious science because of the lack of experimental data owing to the limitations of contemporary technology. This is now changing rapidly, with the discovery of evidence (inter alia) for life on earth quite soon after its formation, for an earthlike climate on early Mars, for a subsurface ocean on Jupiter's moon Europa, for organic chemistry on Titan, and for planets around nearby stars. Soon we may have the answer to a most profound question: how does the ‘software’ of life get written? Is it by random chance, so that original life is very rare, or is it somehow written into the laws of physics and chemistry, so that life is inevitable wherever the conditions are suitable?
Get full access to this article
View all access options for this article.