NASA Discovers Life's Building Blocks Are Common In Space

NASA Discovers Life's Building Blocks Are Common In Space

NASA - October 11, 2005

www.nasa.gov...

After A team of NASA exobiology researchers revealed today organic chemicals that play a crucial role in the chemistry of life are common in space.

"Our work shows a class of compounds that is critical to biochemistry is prevalent throughout the universe," said Douglas Hudgins, an astronomer at NASA's Ames Research Center, Moffett Field, Calif. He is principal author of a study detailing the team's findings that appears in the Oct. 10 issue of the Astrophysical Journal.

"NASA's Spitzer Space Telescope has shown complex organic molecules called polycyclic aromatic hydrocarbons (PAHs) are found in every nook and cranny of our galaxy. While this is important to astronomers, it has been of little interest to astrobiologists, scientists who search for life beyond Earth. Normal PAHs aren't really important to biology," Hudgins said. "However, our work shows the lion's share of the PAHs in space also carry nitrogen in their structures. That changes everything."

"Much of the chemistry of life, including DNA, requires organic molecules that contain nitrogen," said team member Louis Allamandola, an astrochemist at Ames. "Chlorophyll, the substance that enables photosynthesis in plants, is a good example of this class of compounds, called polycyclic aromatic nitrogen heterocycles, or PANHs. Ironically, PANHs are formed in abundance around dying stars. So even in death, the seeds of life are sewn," Allamandola said.

This is the type of discovery that is going to change the way we look at our Galaxy , the Universe and its potential to harbor life!

www.astrochem.org...

"Not only are nitrogen containing aromatic hydrocarbons the information carrying molecules in the DNA and RNA that make up all living matter as we know it, they are found in many biologically important species. For example, caffeine and the main ingredient in chocolate are among these kinds of molecule (Figure 2). Seeing their signature across the Universe tells us they are accessible to young, habitable planets just about everywhere."

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The most common scientific theory for the origin of life on Earth is that somewhere in the vast, but simple, chemical resources available on the early Earth, conditions favored the formation of more complex chemical compounds and chemical processes which eventually led to life. However, this theory was conceived at a time when it was thought space was barren of complex organics because interstellar radiation is too harsh, the distances too great, and violent shocks too frequent to support complex chemistry, let alone survival of large molecules and their transport to planetary surfaces. In sharp contrast to that picture, this new work shows that the early chemical steps believed to be important for the origin of life do not require a previously formed planet to occur. Instead, some of the chemicals are already present throughout space long before planet formation occurs and, if they land in a hospitable environment, can help jump-start the origin of life.

I imagine that this discovery will invigorate SETI , the ExoBiology Fields.

Not to mention that the ETH will get a huge boost in credibility from this discovery also.

The discovery centers around PANHs that are key to biology.

While the PAH model appeared to satisfy many observations made through most of the 90's, the higher quality IR spectra that were beamed back to Earth from The Infrared Space Observatory, ISO, posed new challenges. In analyzing these spectra, Belgian astronomer Els Peeters found small but real mismatches with the Ames spectra. "We measured the complete infrared spectra of over 55 different astronomical objects, many which couldn't be detected before. We found that none of the spectra in the Ames database could reproduce the regular changes we saw that occurred between very old interstellar regions and very young astronomical objects known as planetary nebulae," said Peeters. "That difference showed something important was missing in the Ames dataset and that something told us about PAH evolution" explained Peeters.



"This was about the time we realized that chemically, a nitrogen atom could easily replace a carbon in a PAH's hexagonal skeleton" recalled Hudgins, "but we didn't have a clue as to how that might alter the PAH spectrum." This was also the time when experimental physical chemist and Oklahoman Andrew Mattioda joined the group. "Those were exciting days" Mattioda remembered, "the PAH spectra we had were being used as new tools to analyze regions thousands of light years away and, incredibly, new observations were giving us feedback on the structures of these distant molecules and conditions in the astronomical objects themselves. We geared up to measure the spectra of all the nitrogen containing PAHs (PANHs) we could find, but there weren't many and they are much smaller than those we believe are in space. There are probably hundreds of different PANHs in space and we only had six or seven of the smaller ones." Ultimately, Mattioda's experiments showed that the simple PANHs could not resolve the problem Peeters uncovered.



This was when the computational power came to the fore. Bauschlicher determined the spectra of a variety of species involving PAHs to understand the changes Peeters had found. "Because I can compute the spectra of PAHs much larger than anything that has been synthesized and also vary the placement of nitrogen within these large molecules, something impossible for the lab, we can now investigate a very large number of PAH varieties and sizes." Bauschlicher explained. "With this we have shown we can reproduce both the range in spectral shift Els measured and the relative intensities she found by incorporating N deep into the PAH skeleton" he explained further.



This discovery is profound at several levels. "First, this resolves part of a longstanding mystery about the distribution of nitrogen in space, second, PANHs have signatures in the optical and radio wavelengths that can account for unexplained astronomical phenomena and third, these compounds are of biogenic interest" summed Hudgins. "Most people will take notice of their possible role in the origin of life, the point in our history when chemistry became biology, but there are other serious implications as well" he continued.

Scientists have known about the prevalence of PAHs for awhile , but the discovery of the prevalence of PANHs is a huge discovery!

Something that 20 years ago was considered impossible.

PANHs are far more interesting chemically than PAHs , and they are essential in organic chemistry.

Meaning that this discovery will likely force us to view the Universe not as "Dead" and inorganic , but as "Alive" and Organic by nature. At least chemically.

I know this has probably been hashed out again and again here...and I realize the significance of carbon-based molecules commonly forming in relation to our own biology....but

Wouldn't silicon or germanium, or even tin and lead form some similar complex molecules.....at least that's what I think I remember from chemistry years ago...

I know the further you go down, you have less similiarities, as well....

I guess it all boils down to my personal frustration with the "short-sightedness" of our scientists that publish things like this at times.

What other types of lifeforms do we have to study on earth? All of them are carbon-based life. We have not found any examples of silicon based life so we don't even know if it's possible. I would wager that it is in very very rare circumstances, but I feel comfortable by going out on a limb by saying that Carbon-based is probably the most abundant in the universe. Of course I could be completely wrong and probably am wrong to a certain extent but the point is they can't doing anything about it except try to synthetically create life from said elements you mentioned, there are lots of programs out there trying to do just that but it's very hard stuff as no one has done it before. Sounds like well Science heh.

I don't disagree that carbon-based molecules would be a good starting point......my point is it just seems to me at times that few seem open to the idea of lifeforms of completely different chemical design.
Chemically, carbon more readily than the other elements I mentiond combines with other elements to form complex compounds....so I don't even disagree with your argument that carbon-based life may be the dominant form in this universe. I just don't see why this particular piece of information is "news" or why we aren't looking at complex Si molecules or others, "just in case".

ahnikah makes a good point IMHO, I think some Alien life might be so Alien we wouldn't even reconize it if we saw it. Since we have yet to study any alien life we can't really rule out anything silcon based,energy based whatever.

The only life we have to study is carbon based so we know it does work so I guess that should be our primary objective, But we should also keep our minds and eyes open for other possiblities

Thats what I'm saying we can't really reconize something until a "eureka" moment happens and that has yet to happen unfortunetly. It would be great if we could find some on Earth(or better yet synthesize it in the lab) so we would at least be able to reconize such life but he have not yet. The best bet would be in very hazordous environments, anyone check out Alien Planet that just played on Discovery? Those animals were conjoured up with the help of scientists and what thier collective speculations came up with was something completely alien. Is that show what inspired this thread btw?

Is that show what inspired this thread btw?

No.. this Press Release from NASA yesterday inspired this thread !

www.nasa.gov...

well somehow, i knew this waaay before NASA did, and i dont have a multibillion $ budget

go figure





[edit on 13-10-2005 by nukunuku]

For those that care here is an interesting article about Alternative Biochemistry. It's well worth the read.

en.wikipedia.org...

[edit on 24-11-2005 by sardion2000]

It is posited that silicon molecules are too unstable to allow for life. Carbon is the element of life as we know it and should be (and is) our focus in elemental life studies. This is not a result of short-sightedness, it is due to our prudence.

Zip

Originally posted by Zipdot
It is posited that silicon molecules are too unstable to allow for life. Carbon is the element of life as we know it and should be (and is) our focus in elemental life studies. This is not a result of short-sightedness, it is due to our prudence.

Zip

Oh no doubt but the Above article does highlight some very interesting possibilities, Ammonia based life may be much more likely then Silicon.

Originally posted by nukunuku
well somehow, i knew this waaay before NASA did, and i dont have a multibillion $ budget

go figure

Funnily i have a book printed in 1980 with indicates much the same if not more accurately.... One can only wonder what the hell they did with all their research money since the late 70's!


Stellar