Meteorite that fell last year contains surprising molecules

A space rock that lit up the California sky last year has given scientists an unprecedented look at the complex chemistry that probably took place during the solar system’s infancy. Meteorites similar to this one likely delivered the raw materials to Earth that assembled into the molecules of life.

Scientists have been analyzing pieces of the Sutter’s Mill meteorite since it burst apart over northern California on April 22, 2012 (SN: 1/26/13, p. 5). When Arizona State University chemist Sandra Pizzarello and colleagues melted away some minerals with acid, a plethora of sulfur- and oxygen-containing organic compounds were left behind, several of which have never been identified in meteorites before. They detail their findings September 9 in the Proceedings of the National Academy of Sciences.

The molecules likely formed several billion years ago in conditions similar to those on early Earth: warm and rich in water. “The study provides a little window into what kind of chemistry occurred on Earth before life,” says Jonathan Lunine, a planetary scientist at Cornell University who was not involved in the study. But the work also establishes that this complex chemistry took place long before rocks like this one deposited their molecular treasures on Earth, he says. Since the raw materials were more complex than previously thought, they could have combined more easily to form biological molecules.  

This rare opportunity to analyze a freshly fallen meteorite has Lunine thinking about the bounty of organic materials that may exist on pristine rocks in space. NASA’s OSIRIS-REx probe, due to launch in 2016, will return a sample of material from an asteroid more than 600 million kilometers away.