Researchers at the Max Planck institute in Germany have discovered large quantities of organic molecules at the center of the Milky Way that resemble life-bearing amino acids in their complexity. The new-found presence of this complex organic molecule, iso-propyl cyanide, is a good indicator that amino acids themselves are floating throughout the interstellar medium. If this is indeed the case, it in turn suggests that these wandering amino acids may have played a vital role in the synthesis of life on other planets in the galaxy.
These iso-propyl cyanide molecules were detected in Sagittarius B2, a giant gas-and-dust cloud in the center of the Milky Way that just so happens to be one of our galaxy’s most active stellar nurseries. In Sagittarius B2, there is enough hydrogen gas existing as H2 molecules, and the temperatures are low enough, that gravitational forces can collapse regions of the cloud into dense balls of gas — which then, through a (fantastic) process that’s beyond the scope of this story, eventually ignite into new stars. (Planets are formed in a similar way, incidentally, but we’re not entirely sure of the exact method.) So the theory goes, the heat from these new stars in Sagittarius B2 are heating up some of the dust particles, causing chemical reactions that result in the formation of iso-propyl cyanide (among other molecules).
(The dust, in case you were wondering, is cosmic dust — small particles of simple compounds, such as silicon carbide, aluminium oxide, carbon monoxide, and hydrocarbons, kicked out from stars.)
The Milky Way, behind the ALMA telescopes
A rendering of the future-ALMA, when it has even more telescopes. It’s the largest/most accurate ground-based telescope in the world — but it will be overtaken by the Square Kilometer Array in Australia and South Africa.
These iso-propyl cyanide molecules were detected by the Atacama Large Millimeter Array (ALMA) in Chili — an impressive setup of 20, 12-meter radio telescopes in the Atacama desert. (There are a lot of telescopes down there, as it’s very quiet and very high altitude.) As we’ve covered previously, every element and molecule in the universe has a slightly different spectral fingerprint — it absorbs and emits radiation (light, radio waves) in a very specific way. We already know the spectral fingerprint of iso-propyl cyanide from lab tests here on Earth – and so when we find the same fingerprint emanating from Sagittarius B2, we can be fairly certain that the same molecule is up there, too. Remote analysis like this is known as spectroscopy.
For more info on spectral analysis, read this: Every color of the Sun’s rainbow: Why are there so many missing?
Iso-propyl cyanide… in spaaaace!
Anyway, the detection of iso-propyl cyanide (i-C3H7CN) is significant for one reason: it has a branched structure. Basically, until now, we had only detected organic (carbon) molecules that were straight chains of atoms. Branched molecules, where two or more different atoms connect to a single carbon rather than just one, don’t form so readily — and have more interesting and nuanced properties. As you see in the image above, the normal (n) propyl cyanide has a backbone of uninterrupted carbon atoms; while the iso (i) propyl cyanide has two methyl groups (CH3) branching off the carbon backbone. [DOI: 10.1126/science.1256678 – "Detection of a branched alkyl molecule in the interstellar medium: iso-propyl cyanide"]
The Sun’s spectral fingerprint — similar to what would be produced by
Another example of branched molecules are amino acids — the building blocks of proteins, which in turn are vital to complex life as we know it. Before now, we didn’t know that branched molecules could be readily produced in space. Now, with the discovery of iso-propyl cyanide, it’s possible that amino acids are created at the same time as new stars and planets. “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,” says Arnaud Belloche of the Max Planck Institute for Radio Astronomy, and lead author of the research.
Obviously, if amino acids and other complex molecules are being produced en masse in the universe’s stellar nurseries, then it follows that there are billions or trillions of other planets out there that have been imbued with the basic building blocks of life. The odds of those molecules actually becoming proteins, carbohydrates, and nucleic acids is infinitesimally small — but obviously, the fact that we are here on Earth is a strong indication that it’s far from impossible. The question is, just how many times did life spontaneously arise throughout the universe? (And through methods such as panspermia, would it really be necessary for life to emerge more than once, anyway?)
|Evernote helps you remember everything and get organized effortlessly. Download Evernote.|