From: American Geophysical Union
Posted: Thursday, November 5, 2009
It has been suggested that the organic matter needed for the origin of life could have been delivered to Earth through meteoritic impacts early in Earth's history, but studies have shown that most of the delivered organics would have decomposed through shock heating or aerodynamic interaction with the ambient atmosphere. However, Sugita and Schultz suggest that some of the decomposed organics could have been revived through chemical reactions between the meteoritic matter and the ambient atmosphere during hypervelocity oblique impacts.
As a model for meteoritic impacts in the early atmosphere, they conduct hypervelocity impact experiments in which polycarbonate projectiles impact copper targets in very oxidizing nitrogen- oxygen-argon mixtures, which provide difficult conditions for organic synthesis. Despite the conservative conditions, they find that carbon from the projectile reacts efficiently with atmospheric nitrogen to produce cyanides.
Nitrogen is an important element in biomolecules but is not abundant in meteorites. The authors note that impact-driven cyanide synthesis may have contributed significantly to the basic chemical building blocks needed for the origin of life.
Title: Efficient cyanide formation due to impacts of carbonaceous bodies on a planet with a nitrogen-rich atmosphere
Authors: Seiji Sugita: Department of Complexity Science and Engineering, University of Tokyo, Kashiwa, Japan; Peter H. Schultz: Department of Geological Sciences, Brown University, Providence, Rhode Island, USA.
Source: Geophysical Research Letters (GRL) paper 10.1029/2009GL040252, 2009. http://dx.doi.org/10.1029/2009GL040252
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