Nov 15, 2011

Sweet Spot for Life's Chemistry Discovered

When scientists realized early Earth didn't have the right ingredients for life on its own, they started looking in space for the complex organic molecules needed to get things going.

Of particular interest is methanol, which can trigger the more complex chemistry that leads to amino acids, the building blocks for proteins and life.

"Methanol is the most complex molecule you can form at the really low temperatures in interstellar space," astronomer Douglas Whittet, with Rensselaer Polytechnic Institute, told Discovery News. "When you put methanol into a newly forming star system, you have some heat from a proto-sun and that's when methanol really takes off. It's the springboard for more exciting chemistry that follows."

In other words, find the methanol and scientists believe you find the chemical pathways to life.

"Searching for methanol in various regions in space will tell researchers where to look for other complex organic molecules, which will eventually lead to the formation of life," astronomer Sachindev Shenoy, with NASA's Ames Research Center in California, told Discovery News.

But where to look?

A new analysis by Whittet and colleagues shows there is a "sweet spot" around a few young stars where methanol production is cranking. What seems to be key is how fast molecules can reach dust grains, which serve as a scaffolding of sorts for chemical reactions.

"The rate of molecule accumulation on the particles can result in an organic boom or a literal dead end," Whittet said.

Not all young stars are suited for organic chemistry. Whittet's team found a range of methanol concentrations in clouds from practically zero to about 30 percent.

If molecules build up too quickly on the surfaces of dust grains, there's not enough time for chemical reactions to occur before they are buried by other molecules. If the buildup is too slow, there are fewer chances for chemical reactions.

The research has implications for understanding where to look for life and suggests it may be more plentiful, from a chemistry point of view, than previously thought.

Read more at Discovery News

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