General Chat

A new theory on how life started on earth has been revealed in New Scientist this week. Researchers from Brown University in the USA and Tokyo University in Japan have replicated the effects of an asteroid plunging through earth’s atmosphere in a laboratory at the NASA Ames Research Centre, with intriguing results.

There have been a few theories on how organic material found its way onto earth, but until now the idea that it came from comets and asteroids hitting the planet have been rubbished, due to the extreme temperatures the projectiles are exposed to as they pass through the earth’s atmosphere and then the small fact that they are vaporised on impact.

However, during the high speed impact tests carried out by the scientists they confirmed that while the impacts destroy the original organic molecules, they may also help to create new ones.

They simulated the impacts by firing polycarbonate plastic projectiles at 6 kilometres per second at metal targets and as predicted they were vaporised instantly, just as an asteroid would be.

In the following analysis, they found abundant cyanide consisting of a carbon atom bound to a nitrogen atom – formed by chemical reactions between the projectile's carbon and nitrogen in the air.

According to the scientists cyanide compounds are very reactive, so further reactions involving them on early earth could have led to more complex carbon-containing molecules that are important to life being formed.