Sydney, Feb 27 (IANS): Asteroids hitting the earth cause immense destruction, but some of them may have also played a key role in the evolution of early life, according to new research.

Geologist Martin Schmieder, research associate at the University of Western Australia School of Earth and Environment, who led the study, said that heat generated by an asteroid impact took at least several hundred thousand years to dissipate.

Schmiede said as impact craters cooled, they provided an ideal environment for microbial life to thrive, the journal Geochimica et Cosmochimica Acta reports.

"As a case study, we analysed impact-molten rock samples from the 23 km-diameter and 76-million-year-old Lappajarvi crater in Finland, and were quite surprised by the results," Schmieder said, according to a Western Australia statement.

Temperatures during an impact event can reach several thousand degrees Celsius, capable of melting portions of the target rock, said Schmieder, who co-authored the study with Fred Jourdan, director of the Western Australian Argon Isotope Facility at Curtin University.

The studies were conducted by experts in rocks and minerals from craters produced by the hypervelocity impact of incoming asteroids and comets (termed meteorites once they hit the Earth's surface).

"Although usually associated with massive havoc and destruction, asteroid impacts also acted as extraterrestrial boosters of life in the past," Schmiede said.

"A prime example is the giant Chicxulub impact that helped wipe out dinosaurs 66 million years ago and eventually paved the way for mammals and mankind," Jourdan added.

Smaller to medium-size impact craters less than 30 km across represent the largest crater population on Earth and other planetary bodies, compared with giant impact basins such as those on the Moon that are visible to the naked eye on a clear night.