Thursday, December 11, 2008

Sweet Find in Search for Alien Life

By Jeanna Bryner, Senior Writer

This molecular structure shows glycolaldehyde, which is the most basic sugar and can react to form ribose, the central component of RNA (similar to DNA). Credit: IRAM

A sugar molecule that's linked to the origin of life has been detected in a region of our galaxy where habitable planets could exist. The sweet find is good news in the search for alien life, the researchers say.

Called glycolaldehyde, the sugar molecule is considered a life ingredient because it can react with a substance called propenal to form ribose, a central constituent of ribonucleic acid (RNA), which is similar to DNA and considered one of the central molecules in the origin of life.

An international team of scientists used the IRAM radio telescope in France to detect glycolaldehyde in a massive star-forming region of space, some 26,000 light-years from Earth. (One light-year is the distance light will travel in a year, or about 6 trillion miles, or 10 trillion km.)

They looked for the emission of certain wavelengths within the radio part of the electromagnetic spectrum. Molecules each emit a distinctive band of radio wavelengths, which can be used as a fingerprint for the molecules.

"This is an important discovery as it is the first time glycolaldehyde, a basic sugar, has been detected towards a star-forming region where planets that could potentially harbor life may exist," said researcher Serena Viti of the University College London.

Previously, the organic sugar had been detected toward the center of our galaxy, where conditions are extreme and not conducive to planet-forming compared with the rest of the galaxy.

The new discovery, which will be detailed in a forthcoming issue of Astrophysical Journal Letters, was in an area distant from the galactic center. In addition, the sugar was found in a swirl of gas and dust around a collection of stars. "Possibly, this material is actually rotating around the stars, which may imply that it's a disk and that's where planets may form," Viti told

She added, "Also the fact that it's just a normal star-forming region suggests that the production of this molecule could be common throughout the galaxy."

The detection of one life ingredient also improves the chances that the molecule exists alongside other molecules essential to life and in regions where Earth-like planets may exist, she said.

"The fact that a basic sugar so directly linked to RNA is common makes you think the basic ingredients for life are out there," Viti said. "They're not just on Earth."

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