Asteroid served up ‘custom orders’ of life’s ingredients

June 10, 2011
Tagish Meteorite

One of the Tagish Lake meteorite fragments (credit: Michael Holly, Creative Services, University of Alberta)

Some asteroids may have been like “molecular factories,” generating life’s ingredients and shipping them to Earth via meteorite impacts, scientists at the University of Alberta have determined.

In January 2000, a large meteoroid exploded in the atmosphere over northern British Columbia, Canada, and rained fragments across the frozen surface of Tagish Lake. Pieces were collected within days and kept preserved in their frozen state. This ensured that there was very little contamination from terrestrial life.

They found that various fragments had been exposed to different amounts of water, and suggest that water alteration may account for the diversity in amino acid production. The researchers’ results provide perhaps the first clear evidence that water percolating through the asteroid parent body caused some molecules to be formed and others destroyed.

The Tagish Lake meteorite provides a unique window into what was happening to organic molecules on asteroids four-and-a-half billion years ago, and the pre-biotic chemistry involved, the researchers said.

Ref.: Christopher D. K. Herd, et al., Tagish Lake Meteorite: Origin and Evolution of Prebiotic Organic Matter As Inferred from the Tagish Lake Meteorite, Science, (2011); [DOI: 10.1126/science.1203290]