19 September 2008
Astronomers Discover Key Molecule for Life Floating in Space Between the Stars

A joint news release with the Instituto Astrofísica de Canarias.

FORT DAVIS, Texas — A team of scientists led by researchers from the Instituto Astrofísica de Canarias (IAC) and including University of Texas at Austin astronomer David L. Lambert has succeeded in detecting naphthalene, one of the most complex molecules yet discovered in the gas floating between stars. Their results are published in a recent issue of Astrophysical Journal Letters.

The detection of this molecule suggests that a large number of the key components in Earth's prebiotic chemistry could have been present in the cloud of gas and dust from which our solar system was formed.

The naphthalene was discovered in a star formation region in the constellation Perseus, in the direction of the star Cernis 52.

“We have detected the presence of the naphthalene cation in a cloud of interstellar matter located 700 light-years from the Earth,” said team member Susana Iglesias Groth of IAC. “We aim to investigate whether other, more complex, hydrocarbons exist in the same region, including amino acids.”

In addition to Lambert and Iglesias Groth, the team of researchers includes Arturo Manchado and Aníbal García of IAC and Jonay González of Paris Observatory. For this work, the team used telescopes at The University of Texas at Austin's McDonald Observatory in West Texas as well as in La Palma, Canary Islands.

When subjected to ultraviolet radiation and combined with water and ammonium, both abundant in the space between the stars, naphthalene reacts and is capable of producing a wide variety of amino acids and naphthaloquinones — precursor molecules to vitamins.

All these molecules play a fundamental role in the development of life as we know it on Earth. In fact, naphthalene has been found in meteorites that continue to fall to the surface of Earth, and which fell with much greater intensity in epochs preceding the appearance of life.

The work of these researchers also enables us to understand one of the most intriguing problems in studies of the chemistry of the space between the stars. For the past 80 years, astronomers have recognized hundreds of spectroscopic features (the so-called “diffuse bands”) associated with matter in between stars, but the identification of the agent causing them has remained a mystery.

“Our results show that polycyclic aromatic hydrocarbons such as naphthalene are responsible for the diffuse bands and should be present throughout the interstellar medium,” Iglesias Groth said.

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