Article Posted on : - Nov 03, 2012

WASHINGTON (PTI): Asteroids may have brought life to Earth as scientists claim their collisions with planets can boost the birth and evolution of complex life.

A new study proposes that asteroids may have delivered water and organic compounds to the early Earth, NASA said in a statement.

Researchers suggest that the size and location of an asteroid belt, shaped by the evolution of the Sun's protoplanetary disk and by the gravitational influence of a nearby giant Jupiter-like planet, may determine whether complex life will evolve on an Earth-like planet.

Solar systems with life-bearing planets may be rare if they are dependent on the presence of asteroid belts of just the right mass, according to a study by Rebecca Martin, a NASA Sagan Fellow from the University of Colorado in Boulder, and astronomer Mario Livio of Space Telescope Science Institute.

This might sound surprising because asteroids are considered a nuisance due to their potential to impact Earth and trigger mass extinctions, researchers said.

However, an emerging view proposes that asteroid collisions with planets may provide a boost to the birth and evolution of complex life, they said.

According to the theory of punctuated equilibrium, occasional asteroid impacts might accelerate the rate of biological evolution by disrupting a planet's environment to the point where species must try new adaptation strategies.

The astronomers based their conclusion on an analysis of theoretical models and archival observations of extra-solar Jupiter-sized planets and debris disks around young stars.

"Our study shows that only a tiny fraction of planetary systems observed to date seem to have giant planets in the right location to produce an asteroid belt of the appropriate size, offering the potential for life on a nearby rocky planet," said Martin, the study's lead author.

"Our study suggests that our solar system may be rather special," Martin said.

The findings are published in the Journal of Royal Astronomical Society.