This artist’s conception shows a red dwarf star orbited by a pair of habitable planets. Because red dwarf stars live so long, the probability of cosmic life grows over time. As a result, Earthly life might be considered “premature.” Christine Pulliam (CfA)
The universe is 13.8 billion years old, while our planet formed just 4.5 billion years ago. Some scientists think this time gap means that life on other planets could be billions of years older than ours. However, new theoretical work suggests that present-day life is actually premature from a cosmic perspective.
“If you ask, ‘When is life most likely to emerge?’ you might naively say, ‘Now,'” says lead author Avi Loeb of the Harvard-Smithsonian Center for Astrophysics. “But we find that the chance of life grows much higher in the distant future.”
Life as we know it first became possible about 30 million years after the Big Bang, when the first stars seeded the cosmos with the necessary elements like carbon and oxygen. Life will end 10 trillion years from now when the last stars fade away and die. Loeb and his colleagues considered the relative likelihood of life between those two boundaries.
The dominant factor proved to ...