January 31, 2014
Earthlings may be extreme latecomers to a universe full of life, with alien microbes possibly teeming on exoplanets beginning just 15 million years after the Big Bang, new research suggests.
Traditionally, astrobiologists keen on solving the mystery of the origin of life in the universe look for planets in habitable zones around stars. Also known as Goldilocks zones, these regions are considered to be just the right distance away from stars for liquid water, a pre-requisite for life as we know it, to exist.
But even exoplanets that orbit far beyond the habitable zone may have been able to support life in the distant past, warmed by the relic radiation left over from the Big Bang that created the universe 13.8 billion years ago, says Harvard astrophysicist Abraham Loeb.