It came from outer space. It being the stuff of life—amino acids, sugars and other organic molecules.

Meteorites reveal startling assortments of such prebiotic compounds. So it's possible that asteroids and comets delivered the ingredients for life billions of years ago. And a new study shows that asteroids weren't just passive couriers of organic material.

Researchers analyzed four fragments of the Tagish Lake meteorite, which broke apart over northwest Canada in 2000. They found a rich assortment of organic compounds, as well as great variation among the specimens. One piece of the meteorite had more than 100 times the amount of amino acids as another piece.

These results indicate that chemical reactions were taking place on the asteroid that spawned the meteorite. And some of those reactions probably created molecules important to life. The work is in the journal Science. [Christopher Herd et al., "Origin and Evolution of Prebiotic Organic Matter As Inferred from the Tagish Lake Meteorite"]

The new study was made possible by citizen scientist and outdoorsman Jim Brook. He collected pristine samples of the meteorite just days after they fell on the frozen lake, and stored them in his freezer. It’s a good thing he did, because origin of life research is very cool.

—John Matson

[The above text is an exact transcript of this podcast.]