Washington: There are numerous theories on how life spawned on Earth and now a new research has indicated that life came from an interstellar origin; hitched a ride on a speck of dust, blew out of its host star system by stellar winds and then ended up on our planet. This concept is called `anspermia`.
"Biologically, the destructive effects of ultraviolet light and cosmic rays means that the majority of organisms arrive broken and dead on a new world," Discovery News quoted Paul Wesson, a visiting researcher at the Herzberg Institute of Astrophysics in Canada, as saying.
"The likelihood of conventional forms of panspermia must therefore be considered low," he added.
Although these comments don`t necessarily rule out panspermia as a cosmic life-spreading mechanism, Wesson does raise an important point.
Although we know terrestrial life can survive for long periods in space, we`ve only tested how life copes in space for months or years. Panspermia is thought to operate over much longer timescales, possibly millions of years.
This is why Wesson suggests the panspermia concept may need to be modified for interstellar hops when life dies and its genetic chemical bonds degrade in transit.
Although it sounds more like the title of a sci-fi horror movie, he has coined the term "necropanspermia" to describe a rather macabre means of transferring life around the cosmos. Dead organisms could spawn new life.
If the destination is hospitable, the conditions might be right for the dead microbes` genetic code to be reassembled.
"Resurrection may, however, be possible. Certain micro-organisms possess remarkably effective enzyme systems that can repair a multitude of strand breaks," Wesson concluded.
The research paper published in the journal Space Science Review.