Scientists have speculated that life could have come to Earth from space — a notion called panspermia — since the 1870s, when Lord Kelvin suggested microbes could have ridden here on a comet or meteor. Others have suggested tiny organisms could cross the galaxy embedded in dust grains, which could be nudged from one planetary system to another by the slight pressure of stars’ radiation.
However, most astrobiologists think that same radiation spells a death sentence for delicate microbes.
“That essentially kills panspermia in the classical sense,” said astrobiologist Rocco Mancinelli of the SETI Institute in Mountain View, California.
But maybe not, says astronomer Paul Wesson, a visiting researcher at the Herzberg Institute of Astrophysics in Canada. In an upcoming paper in Space Science Reviews, Wesson argues that even if the actual microbes are dead on arrival, the information they carry could allow life to rise from the charred remains, an idea he calls necropanspermia.
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