2007-08-31

Cosmic Cockroaches

August 31, 2007: Starved. Stomped. Radiated. Poisoned. It's all in a day's work for the common household cockroach. The abuse these creatures can withstand is amazing.

But astronomers have found something even tougher—"polycyclic aromatic hydrocarbons," says Achim Tappe of the Harvard Center for Astrophysics. "They can survive a supernova."

see captionPolycyclic aromatic hydrocarbons (PAHs for short) are ring-shaped molecules made of carbon and hydrogen. They're about as well loved as roaches: PAHs are a widespread organic pollutant, appearing in auto exhaust, oil spills and cigarette smoke. The EPA has classified seven PAH compounds as human carcinogens.
see caption
Right: A ball-and-stick model of the polycyclic aromatic hydrocarbon naphthalene, commonly found in mothballs.

But even PAHs have their virtues: Ring-shaped molecules similar to PAHs are found in DNA, and there's a growing consensus among biologists that PAHs were present on Earth 4.5 billion years ago when life began. By serving as building blocks for larger molecules of life, PAHs may have played an essential role in the chemical process of genesis.

That's why Tappe's recent discovery may be so important.

http://science.nasa.gov/headlines/y2007/31aug_cockroaches.htm?list212057

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