Thu Feb 28, 2013, 07:59 PM

Redfairen (1,276 posts)

Ingredients to DNA Discovered in Interstellar Space - Cosmic Origin of Life

Ever wondered where life may have originated? It turns out that some basic chemicals that are key to DNA may be located in space. Researchers have discovered an important pair of prebiotic molecules in interstellar space.

Using the National Science Foundation's Green Bank Telescope (GBT), researchers studied a giant cloud of gases located about 25,000 light-years away from Earth, near the center of our Milky Way Galaxy. They used new technology to speed the process of identifying the "fingerprints" of cosmic chemicals located in this cloud. Since each molecule has a specific set of rotational states, and since it emits or absorbs a specific amount of energy when it changes from one state to another, scientists were able to identify these molecules by using the GBT. During these state changes, the GBT could detect radio waves at specific frequencies which it then relayed to the researchers. The scientists then measured the characteristic patterns of these radio frequencies for specific molecules.

What did they find exactly? Scientists were able to discover a molecule that is thought to be a precursor to a key component in DNA and another that may have a role in the formation of the amino acid alanine. In particular, one of the molecules is called cyanomethanimine, which is one step in the process that chemists believe produces adenine. Adenine is one of four nucleobases that form the "rungs" seen on the double-helix, ladder-like structure of DNA. The other molecule, ethanamine, plays a role in forming alanine, which is one of the twenty amino acids in the genetic code.

"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 in a press release.

http://www.scienceworldreport.com/articles/5274/20130228/ingredients-dna-discovered-interstellar-space-cosmic-origin-life.htm

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6 replies	Author	Time	Post
Ingredients to DNA Discovered in Interstellar Space - Cosmic Origin of Life (Original post)	Redfairen	Feb 2013	OP
It would also mean that other life forms would share some very basic structures	Jackpine Radical	Feb 2013	#1
The great advantage of science ...	DreamGypsy	Feb 2013	#5
Sounds like life is a basic function of the universe.	hedda_foil	Feb 2013	#2
Can we necessarily say they are precursors? Could be a giant crematory...	Thor_MN	Feb 2013	#3
This work has been reported before: Student team discovers new interstellar molecule ...	DreamGypsy	Feb 2013	#4
Wow, talk about jumping to conclusions from minimal evidence.	eppur_se_muova	Feb 2013	#6

Response to Redfairen (Original post)

Thu Feb 28, 2013, 08:04 PM

Jackpine Radical (45,274 posts)

1. It would also mean that other life forms would share some very basic structures

with us.

Now, the question is, how did those goddam complex organics form out there? And for that matter, where out there?

That's the goddam problem with science. Every answer generates 10 more questions.

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Response to Jackpine Radical (Reply #1)

Thu Feb 28, 2013, 09:03 PM

DreamGypsy (2,252 posts)

5. The great advantage of science ...

... is that when you think of a goddam question someone has probably already thought about a possible dogdam answer.

Here's some information from another of today's articles on this discovery/announcement, from SciTechDaily (emphasis mine):

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.

“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).

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.

Some chemists out there can probably explain techniques for synthesizing cyanomethanimine. Probably the earthbound methods involve water somewhere in the synthesis...so the astrochemists look for sources of water in interstellar space.

The universe is a great big beaker...just have to add the right chemicals at the right time.

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Response to Redfairen (Original post)

Thu Feb 28, 2013, 08:10 PM

hedda_foil (16,153 posts)

2. Sounds like life is a basic function of the universe.

Who knows, maybe our galaxy will turn out to be inhabited by Vulcans and Romulans or ...?

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Response to Redfairen (Original post)

Thu Feb 28, 2013, 08:23 PM

Thor_MN (11,843 posts)

3. Can we necessarily say they are precursors? Could be a giant crematory...

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Response to Redfairen (Original post)

Thu Feb 28, 2013, 08:46 PM

DreamGypsy (2,252 posts)

4. This work has been reported before: Student team discovers new interstellar molecule ...

From PHYS.ORG, August 1, 2012, Student team discovers new interstellar molecule during summer program

Left to Right: Kennedy Johnson, Johnson C. Smith University; Nicole Sciortino, St. Augustine's College; Jolie Nyiramahirwe, Piedmont Virginia Community College; and David Vasquez, Virginia Tech

Recently, a team of undergraduate students from four universities visiting the University of Virginia to take part in a special eight-week summer research program for minority students made one of those rare discoveries. It's called cyanomethanimine, and is considered a precursor molecule for RNA, a key building block for the development of life on this planet – and possibly elsewhere in the universe.

The students conducted experiments in the astrochemistry lab of chemist Brooks Pate of U.Va.'s College of Arts & Sciences and used data from the National Radio Astronomy Observatory's Green Bank Telescope in Green Bank, W.Va., to verify their finding.

"This is a pretty special discovery and proves that early-career students can do remarkable research," said Pate, one of a team of program mentors that included U.Va. astronomy professor Ed Murphy and National Radio Astronomy Observatory scientist Anthony Remijan.

<snip>

The team applied for, and was granted, additional telescope time from NRAO at Green Bank to conduct further experiments using additional frequencies. "Not many people get to go to Green Bank," noted Kennedy, "but we did!"

What's really cool is that these four undergraduate women and men get their first scientific publication in The Astrophysical Journal Letters:

Detection of E-cyanomethanimine towards Sagittarius B2(N) in the Green Bank Telescope PRIMOS Survey

Daniel P. Zaleski, Nathan A. Seifert, Amanda L. Steber, Matt T. Muckle, Ryan A. Loomis, Joanna F. Corby, Oscar Martinez, Jr., Kyle N. Crabtree, Philip R. Jewell, Jan M. Hollis, Frank J. Lovas, David Vasquez, Jolie Nyiramahirwe, Nicole Sciortino, Kennedy Johnson, Michael C. McCarthy, Anthony J. Remijan, Brooks H. Pate
(Submitted on 5 Feb 2013)

The detection E-cyanomethanimine (E-HNCHCN) towards Sagittarius B2(N) is made by comparing the publicly available Green Bank Telescope (GBT) PRIMOS survey spectra (Hollis et al.) to laboratory rotational spectra from a reaction product screening experiment. The experiment uses broadband molecular rotational spectroscopy to monitor the reaction products produced in an electric discharge source using a gas mixture of NH3 and CH3CN. Several transition frequency coincidences between the reaction product screening spectra and previously unassigned interstellar rotational transitions in the PRIMOS survey have been assigned to E cyanomethanimine. A total of 8 molecular rotational transitions of this molecule between 9 and 50 GHz are observed with the GBT. E-cyanomethanimine, often called the HCN dimer, is an important molecule in prebiotic chemistry because it is a chemical intermediate in proposed synthetic routes of adenine, one of the two purine nucleobases found in DNA and RNA. New analyses of the rotational spectra of both E-cyanomethanimine and Z-cyanomethanimine that incorporate previous mm-wave measurements are also reported.

Hooray for upcoming scientists!!

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Response to Redfairen (Original post)

Thu Feb 28, 2013, 10:50 PM

eppur_se_muova (35,363 posts)

6. Wow, talk about jumping to conclusions from minimal evidence.

These are both MUCH simpler molecules than any nucleic acid heterocycles, or all but the simplest amino acid (glycine). The first is just the dimer of hydrogen cyanide, found pretty much wherever HCN is found. This fad of reporting "MOLECULES OF LIFE FOUND IN SPACE!" has gotten really old. There is a very long and improbable path between such spaceborne molecules and all but the simplest amino acids or nuclear bases. In contrast, the formation of these molecules under planetary conditions is well documented. The main difference is simply concentration -- the probability of two molecules reacting with each other is proportional to the concentration of each of the molecules involved, which is much, much lower in instellar space than in planetary atmospheres/hydrospheres. I wish these scientists would try harder to formulate plausible hypotheses, rather than going for the most spectacular hypothesis in the hopes of greater fame -- which is evidently what is driving this fad.

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