Scientists have found that asteroid and comet impact craters must be our priorities in finding the evidences of life on other planets.
In the present study, scientists have found complex organic material enclosed in glassy ejecta, produced during a meteor impact in western Tasmania about 800,000 years ago. The impact crated the 1.2-kilometre wide Darwin Crater, near Queenstown, Tasmania.
“When large meteors strike the Earth at incredibly high speeds of up to 18 kilometres per second, the energy released, causes solid rocks to melt and blast into the air,” said one of the study’s authors Professor Phil Bland of Curtin University in Perth.
“The droplets of molten rock called tektites, then rain down over large areas, solidifying into glass fragments as they fall.”
Scientists melt down the glass from Darwin Crater and found tiny spheres of carbon rich material with complex organic signatures including cellulose, lignin, aliphatic biopolymers and protein remnants.
“This material told us that the asteroid which made the Darwin Crater, had crashed into an ancient rainforest and wet swampy environment,” Bland said in a statement.
He is of the opinion that such craters and glasses would also be produced from meteors on Mars.
“On planets like Mars, impact glasses may survive billions of years, possibly providing evidence for long extinct Martian organisms,” Bland said.
“So it’s possible that if there were environments on Mars where there was life, then we might see evidence of that in impact glasses sitting on the Martian surface,” Bland added.
“Life in those environments might be long gone, but the trace evidence might still be there.”
Signs of life preserved in meteor glass – ABC News (http://www.abc.net.au/science/articles/2013/11/20/3890989.htm)
Kieren Torres Howard et al. (2013). Biomass preservation in impact melt ejecta Nature Geoscience DOI: 10.1038/ngeo1996