[meteorite-list] New Molecule Found in Space Connotes Life Origins

[Ron Baalke]

http://news.cornell.edu/stories/2014/09/new-molecule-found-space-connotes-life-origins

New molecule found in space connotes life origins
By Blaine Friedlander
Cornell Chronicle
September 25, 2014

Hunting from a distance of 27,000 light years, astronomers have discovered 
an unusual carbon-based molecule - one with a branched structure - contained 
within a giant gas cloud in interstellar space. Like finding a molecular 
needle in a cosmic haystack, astronomers have detected radio waves emitted 
by isopropyl cyanide. The discovery suggests that the complex molecules 
needed for life may have their origins in interstellar space.

Using the Atacama Large Millimeter/submillimeter Array, known as the ALMA 
Observatory, a group of radio telescopes funded partially through the 
National Science Foundation, researchers studied the gaseous star-forming 
region Sagittarius B2.

Astronomers from Cornell, the Max Planck Institute for Radio Astronomy 
and the University of Cologne (Germany) describe their discovery in the 
journal Science (Sept. 26.)

Organic molecules usually found in these star-forming regions consist 
of a single "backbone" of carbon atoms arranged in a straight chain. But 
the carbon structure of isopropyl cyanide branches off, making it the 
first interstellar detection of such a molecule, says Rob Garrod, Cornell 
senior research associate at the Center for Radiophysics and Space Research. 

This detection opens a new frontier in the complexity of molecules that 
can be formed in interstellar space and that might ultimately find their 
way to the surfaces of planets, says Garrod. The branched carbon structure 
of isopropyl cyanide is a common feature in molecules that are needed 
for life - such as amino acids, which are the building blocks of proteins. 
This new discovery lends weight to the idea that biologically crucial 
molecules, like amino acids that are commonly found in meteorites, are 
produced early in the process of star formation - even before planets 
such as Earth are formed.

Garrod, along with lead author Arnaud Belloche and Karl Menten, both of 
the Max Planck Institute for Radio Astronomy, and Holger Muller, of the 
University of Cologne, sought to examine the chemical makeup of Sagittarius 
B2, a region close to the Milky Way's galactic center and an area rich 
in complex interstellar organic molecules.

With ALMA, the group conducted a full spectral survey - looking for fingerprints 
of new interstellar molecules - with sensitivity and resolution 10 times 
greater than previous surveys.

The purpose of the ALMA Observatory is to search for cosmic origins through 
an array of 66 sensitive radio antennas from the high elevation and dry 
air of northern Chile's Atacama Desert. The array of radio telescopes 
works together to form a gigantic "eye" peering into the cosmos.

"Understanding the production of organic material at the early stages 
of star formation is critical to piecing together the gradual progression 
from simple molecules to potentially life-bearing chemistry," said Belloche.

About 50 individual features for isopropyl cyanide (and 120 for normal-propyl 
cyanide, its straight-chain sister molecule) were identified in the ALMA 
spectrum of the Sagittarius B2 region. The two molecules - isopropyl cyanide 
and normal-propyl cyanide - are also the largest molecules yet detected 
in any star-forming region.