#sutter's mill

Complex organic molecules in meteorite

On April 22, 2012, a streak of light was observed in the sky above a large portion of California. The light was the fall of a meteorite now known as the Sutter’s Mill Meteorite, named after the same mill where the California Gold Rush began.

When a meteorite fall is observed, it’s a great thing for science because meteorites don’t last long sitting on Earth’s surface. They interact with the atmosphere, soil, and water, rapidly changing the chemistry. A number of teams both private and led by researchers from NASA hit the ground in the days after the meteorite fell, even picking up chunks of it in foil to avoid contamination from their hands (as you see NASA Ames researcher Dr. Peter Jenniskens doing in this photo).

The chunks of that meteorite were first taken into the lab and classified. The codes for meteorites are more than a bit esoteric, but this one was classified as a “CR chondrite”, which is a really interesting rock type. C-chondrites are fairly rare and they’re some of the most primitive, least-processed material in the solar system. They were never heated up and melted like many of the other meteorites that fall to Earth, and they have been found to contain organic molecules left over from the cloud that formed the solar system. C-chondrites give us some of the best information available about what the original solar system was made of, and this rock was one of them.

Because it was observed to fall, it was collected rapidly before it could be altered by the environment, and chunks were preserved in ways that protected any organic molecules in the section. For science, protecting pieces of this meteorite made it likely that this would be a great fall for science, and a very interesting paper has just been published.

Since the rock was a C-chondrite, researchers from Arizona State took portions of it, dissolved it in various acids to remove the rock components, and used techniques from organic chemistry – nuclear magnetic resonance spectroscopy and combined gas-chromatograph/mass spectroscopy analyses on the samples.

They found some organic molecules that had been seen in previous CR chondrites, but there was a class of compounds found in this sample not previously seen; complex polyether- and ester-containing alkyl molecules. The organic chemistry is a bit beyond my expertise, but according to the text there are several important conclusions to be drawn from finding them.

First, they add another component to the “primordial soup” that was likely delivered to most planets. Secondly, they are a component in many basic organic molecule types observed today such as those that make up lipids; having them delivered to a primordial planet means they were available as building blocks for possible life and could have contributed to development of parts such as cell membranes. Finally, these compounds are also quite stable and so if they were delivered to an early planet, they would be expected to survive and contribute to the chemistry until something developed that was able to make use of them or process them. Something like, for example, an organism.

-JBB

Image credit: NASA Ames/ Peter Jenniskens http://www.nasa.gov/centers/ames/news/releases/2012/12-93AR.html

Original paper: http://www.pnas.org/content/early/2013/09/04/1309113110

Jan 24

The discovery of gold in California in the mid-19th Century ushered in one of the largest migrations in American history, as tens of thousands of hopeful, excited, and just plain desperate participated in the California Gold Rush.

It all began on January 24, 1848, on the South Fork of the American River, near what is now the California town of Coloma. John Sutter had hired a number of people to build a saw mill in the area, and James Marshall was one of the people doing the constructing. On that fateful day, Marshall saw tiny pieces of gold in the runoff millwater. He collected some of the gold pieces and showed them to Sutter, who swore Marshall to secrecy.

True.