Milky Way's Vast Molecular Clouds --Creating the Chemical Precursors of DNA
Follow the Daily Galaxy
Add Daily Galaxy to igoogle page AddThis Feed Button Join The Daily Galaxy Group on Facebook Follow The Daily Galaxy Group on twitter
 

« The Milky Way's Violent Core --"Was It the Site of an Ancient Collision of Black Holes?" | Main | Globular Clusters & the Enigma of "Blue Stragglers" »

May 01, 2013

Milky Way's Vast Molecular Clouds --Creating the Chemical Precursors of DNA

 

            W3-giant-molecular-cloud-1600

 

NASA's GLIMPSE (Galactic Legacy Infrared Mid-Plane Extraordinaire) ten-year survey was taken from earth-trailing Spitzer Space Telescope. The GLIMPSE mission was to do a deep panorama of our galaxy in the mid-infrared and to penetrate our galaxy’s dark molecular clouds where some of our Milky Way’s estimated 400 billion stars are actually still forming.

The image at the top of the page shows W3, an enormous stellar nursery about 6200 light-years away in the Perseus Arm, one of the Milky Way galaxy’s main spiral arms, that hosts both low- and high-mass star formation. In this image, the low-mass protostars are seen as tiny yellow dots embedded in cool red filaments, while the highest-mass stars – with greater than eight times the mass of our Sun – emit intense radiation, heating up the gas and dust around them and appearing here in blue.

Scientists using the National Science Foundation's Green Bank Telescope (GBT) in West Virginia to study a giant cloud of gas some 25,000 light-years from Earth, near the center of our Milky Way Galaxy, have discovered a molecule thought to be a precursor to a key component of DNA and another that may have a role in the formation of the amino acid alanine.

During the past decade, astrochemists have found that DNA molecules, the fundamental building blocks of life, are the language of the Universe --the information they inherited comes from the stars and the cosmic ecology that formed them.

DNA is the result of life on Earth, rather than its origin. Over the past decade, molecular paleontologistsand astrochemists have found foundational components of DNA not only in molecular clouds, but also in stony meteorites, chondrites --agglomorations of cosmic sediments, the original particles present in the solar nebula and protoplanetary disk.

"Finding these molecules in an interstellar gas cloud means that important building blocks for DNA and amino acids can 'seed' newly-formed planets with the chemical precursors for life," said Anthony Remijan, of the National Radio Astronomy Observatory (NRAO).
One of the newly-discovered molecules, called cyanomethanimine, is one step in the process that chemists believe produces adenine, one of the four nucleobases that form the "rungs" in the ladder-like structure of DNA. The other molecule, called ethanamine, is thought to play a role in forming alanine, one of the twenty amino acids in the genetic code.

In each case, the newly-discovered interstellar molecules are intermediate stages in multi-step chemical processes leading to the final biological molecule. Details of the processes remain unclear, but the discoveries give new insight on where these processes occur. Previously, scientists thought such processes took place in the very tenuous gas between the stars. The new discoveries, however, suggest that the chemical formation sequences for these molecules occurred not in gas, but on the surfaces of ice grains in interstellar space.

"We need to do further experiments to better understand how these reactions work, but it could be that some of the first key steps toward biological chemicals occurred on tiny ice grains," Remijan said.

The discoveries were made possible by new technology that speeds the process of identifying the "fingerprints" of cosmic chemicals. Each molecule has a specific set of rotational states that it can assume. When it changes from one state to another, a specific amount of energy is either emitted or absorbed, often as radio waves at specific frequencies that can be observed with the GBT.

New laboratory techniques have allowed astrochemists to measure the characteristic patterns of such radio frequencies for specific molecules. Armed with that information, they then can match that pattern with the data received by the telescope. Laboratories at the University of Virginia and the Harvard-Smithsonian Center for Astrophysics measured radio emission from cyanomethanimine and ethanamine, and the frequency patterns from those molecules then were matched to publicly-available data produced by a survey done with the GBT from 2008 to 2011.

The researchers are reporting their findings in the Astrophysical Journal Letters.

The Daily Galaxy via The National Radio Astronomy Observatory

Image Credit: ESA/PACS & SPIRE consortia, A. Rivera-Ingraham & P.G. Martin, Univ. Toronto, HOBYS Key Programme (F. Motte)

 

Comments

Hmmm, left handed spiralling of amino acids have been produced in sterile water with exposure to cosmic radiation here on Earth in a laboratory. Comets are mostly made up of water, travel through a cosmic radiation environment and fall into planets all the time; All that seems to be needed is liquid water. I'm not sure this story is significant.

I love your facebook group page!
http://www.facebook.com/groups/DailyGalaxy

Re: "During the past decade, astrochemists have found that DNA molecules, the fundamental building blocks of life, are the language of the Universe --the information they inherited comes from the stars and the cosmic ecology that formed them.

DNA is the result of life on Earth, rather than its origin. Over the past decade, molecular paleontologistsand astrochemists have found foundational components of DNA not only in molecular clouds, but also in stony meteorites, chondrites --agglomorations of cosmic sediments, the original particles present in the solar nebula and protoplanetary disk."

Something's not right here. These two pararaphs are contradictory. Either DNA is information inherited from the stars or it is the result of life on Earth. Both cannot be the "origin". Could someone at DG explain this a little bit better?

Another thought from my last post;. I wonder if the production and left handed spiralling of amino acids in sterile water from exposure to cosmic radiation is possible in the absence of a magnetic field such as on earth. If life processes are closely linked to the earths mag field then advanced life would be a prerequisite for having evolved the technology to create apparatus for it to survive beyond its parent planet. Could it be that these finger prints of cosmic chemicals are actually evidence of advanced alien life spreading through the galaxy?


Post a comment

« The Milky Way's Violent Core --"Was It the Site of an Ancient Collision of Black Holes?" | Main | Globular Clusters & the Enigma of "Blue Stragglers" »




1


2


3


4


5


6


7


8





9


11


12


13


14


15

Our Partners

technology partners

A


19


B

About Us/Privacy Policy

For more information on The Daily Galaxy and to contact us please visit this page.



E