Ethylene glycol, the chemical commonly used as automobile antifreeze,
was discovered recently in a massive interstellar cloud of dust and gas
near the center of the Milky Way Galaxy. Scientists used the National
Science Foundation’s (NSF) 12 Meter Radio Telescope to detect this
organic molecule.

“Though we most commonly think of ethylene glycol as antifreeze, it
actually is associated with the formation of more complex sugar
molecules that are necessary for life,” said Jan M. Hollis of NASA
Goddard Space Flight Center in Greenbelt, Maryland. “Finding this
molecule supports the view that prebiotic chemistry may first get
started in interstellar space.”

Hollis collaborated with Frank J. Lovas of the University of Illinois,
Philip R. Jewell of the National Radio Astronomy Observatory (NRAO), and
Laurent H. Coudert of the University of Paris at Campus d’Orsay to
identify the ethylene glycol molecule. Their results were accepted for
publication in the Astrophysical Journal Letters.

The scientific team detected ethylene glycol in the molecular cloud
called Sagittarius, located 26,000 light-years from Earth near the
center of our Galaxy. Though rarefied by Earth standards, interstellar
clouds like this one can enable complex chemical reactions over time
scales of hundreds-of-thousands or even millions of years. About 130
different molecules are known to exist in interstellar clouds.

Ethylene glycol (a 10-atom molecule made up of carbon, hydrogen, and
oxygen) is one of the five largest molecules ever discovered in space.
It also is a chemically reduced form of 8-atom glycolaldehyde, the
simplest member of the sugar family. This means that ethylene glycol
can be produced from glycolaldehyde by the addition of two hydrogen
atoms. Both molecules have now been detected in space by this team.

“These detections suggest that the production of more complex sugars,
like ribose, may be occurring in interstellar clouds,” Hollis said.
Ribose sugar is required for the backbone structure of RNA; a less
complex form, deoxyribose sugar, is required for the backbone structure
of DNA.

“This discovery further demonstrates how important interstellar
chemistry may be to understanding the creation of biological molecules
on the early Earth,” said Jewell. “Some scientists have even speculated
that the Earth could have been ‘seeded’ with complex molecules from
passing comets, which were formed from the condensing gas nebula that
produced our Solar System.”

Astronomers on Earth are able to detect and identify the faint radio
emission of molecules in space as they tumble and vibrate within
interstellar clouds, emitting radio waves at precise frequencies. These
frequencies are unique to each molecule, and provide a “fingerprint” in
the electromagnetic spectrum. Signals from other molecules can
sometimes fall at nearby frequencies, in effect smudging the ethylene
glycol fingerprint. The scientists used four different signals from
ethylene glycol to secure its detection.

The researchers made their discovery with data taken in May 2000 with
the 12 Meter Radio Telescope at Kitt Peak, Arizona, which has been a
pioneering instrument in detecting molecules in space. Though operated
by NRAO at the time, this telescope now is operated by the Steward
Observatory of the University of Arizona. The research team plans
future work on interstellar biomolecules using the new NRAO Robert C.
Byrd Green Bank Telescope, which promises to be the most sensitive
telescope yet for such work.

The National Radio Astronomy Observatory is a facility of the National
Science Foundation, operated under cooperative agreement by Associated
Universities, Inc.

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Additional Contact:

Jan M. Hollis

Phone: 301-286-7591

Email: hollis@achamp.gsfc.nasa.gov

Philip Jewell

Phone: 304-456-2301

Email: pjewell@nrao.edu

Editors:

An image of the 12 Meter Telescope is available on:
http://www.tuc.nrao.edu/jpg/12m_50.jp

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A graphic of the molecule ethlene glycol is available on:
http://www.cv.nrao.edu/~cblue/eg.jpg