Mountain View, CA — A team of scientists including SETI
Institute and NASA researchers today announced the
successful creation of amino acids, chemicals essential to
life, in a laboratory simulation of conditions found in deep
space.

At NASA’s Ames Research Center, Moffett Field, CA, the team
reproduced the freezing conditions that exist in the
gigantic interstellar clouds of dust, gas, and ice that are
the birthplaces of new stars and planetary systems.

In their experiment, NASA scientists simulated space-like
conditions by freezing mixtures of common molecules found in
interstellar clouds then exposed them to ultraviolet
radiation. When analyzed, the resulting material contained
glycine, alanine, and serine, amino acids that play central
roles in all living organisms on Earth. The team reported
its results in the March 28 issue of the journal Nature.

“We had previously shown that the chemistry that occurs
under these conditions makes a number of different types of
organic compounds of biological interest,” said Dr. Max
Bernstein, first author and chemist at the Center for the
Study of Life in the Universe at the SETI Institute and NASA
Ames, “but because of their critical role in life on Earth,
we really wanted to see if amino acids were in the mix.”

“A variety of amino acids have previously been detected in
certain kinds of primitive meteorites,” noted Dr. George
Cooper of Ames. “Their presence in meteorites proves that
amino acids are, in fact, made in space. However, it has
generally been thought that they were produced in the solar
system within asteroids, the sources of most meteorites.
Our latest work suggests that at least some of the amino
acids found in meteorites may predate our solar system.”

“Indeed,” noted Dr. Scott Sandford of Ames, “these findings
are particularly intriguing because the amino acids found in
meteorites do show some signatures that suggest an
interstellar connection. This connection, combined with our
finding that amino acids can be made in interstellar clouds
suggests that the Earth may have been seeded with amino
acids from space in its earliest days.”

“The infall of these materials on the early Earth may have
facilitated the origin of life on our planet,” said Dr.
Jason Dworkin of the SETI Institute and Ames. “Furthermore,
since new stars and planets are formed within the same
clouds in which new amino acids are being created, this
probably increases the odds that life has evolved
elsewhere.”

“It now seems possible that at least some of the amino acids
found in meteorites predate the formation of our solar
system and were in fact synthesized in interstellar space.
If they were incorporated into meteorites, it’s natural to
ask if they would have been incorporated into comets as
well. Since recent work [Amino acid survival in large
cometary impacts (E. Pierazzo and C.F. Chyba). 1999.
Meteoritics and Planetary Science 32, 909-918.] suggests
that some amino acids should survive cometary impacts with
Earth, there may be a direct link between prebiotic organic
molecules on early Earth and interstellar space,” says Dr.
Christopher Chyba, a recent MacArthur Award winner who holds
the Carl Sagan Chair and heads the Center for the Study of
Life in the Universe (LITU) at the SETI Institute.

Previously, members of this team had demonstrated that
irradiation of interstellar ice analogs results in the
production of other compounds that are also of potential
biological interest. These include a class of compounds
called amphiphiles that can self-organize to form membranes
and a class of compounds called quinones, aromatic ketones
that play important roles in the metabolisms of living
organisms on the modern Earth. “Taken in combination, these
results suggest that interstellar chemistry may have played
a significant part in supplying the Earth with some of the
organic materials needed to get life started,” Sandford
concluded.

The mission of the SETI Institute is to explore, understand
and explain the origin, nature, prevalence and distribution
of life in the universe.

More detailed information about these findings can be found
at:

http://astrochem.org.

More information about the SETI Institute can be found at
www.seti.org

Information about the Center for the Study of Life in the
Universe can be found at
http://www.seti.org/science/litu/Welcome.html

SETI Institute

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Mountain View, CA 94043

(650) 961-6633

Contacts:

Diane Richards

Marketing and Communications Officer

(650) 960-4513

drichards@seti.org

Taylor Bucci

Center for the Study of Life in the Universe

(650) 960-4519