“Just So Science” – Complex Star Dust

By Elf Eldridge 09/11/2011


Finally getting around to reading Carl Sagan’s magnificent book, ‘Cosmos’, has had the rather wonderful effect of helping re-focus my attention from the worrying political ranting that goes hand-in-hand with every election, and turn once again my attention to the stars. I find it quite amazing just how distracting society and life down here can be, and the wonderful clarity and space that stems from placing your eye to a telescope and gazing at ancient, majestic alien worlds. There’s something deceptive about star gazing, that you only realise how little you can actually see, when you take the time to actually look. There seems to be a general attitude now that humans have, that we have discovered many of the most interesting mysteries of the cosmos – when nothing….absolutely nothing, could be further from the truth. We forget how little we do know, how limited our perceptions and senses actually are and begin to think ourselves masters of our own little corner of the universe.

And then we get results like this, published in Nature, that help push back the boundaries of our perception and serve as a poignant reminder, that our ‘truths’ are often subject to change – especially in science that is, by definition, beyond our little blue world. Kwok and Zhang, two astophysicists from China – took their time to look and listen to what the heavens were telling us. They are not the only astronomers to have done this of course, but they are one of the latest sucess stories. For the last 20 years, astronomers and astrophysicists alike have laboured under the impression that ‘peaks’ at certain wavelengths of infrared light throughout our galaxy and others, are due to the presence of ‘polycylic aromatic hydrocarbons’ or PAHs littered through space. Except there’s a problem – this theory doesn’t match what we actually see. What Kwok and Zhang did was to ask “what DOES match what we see?”, and what they found are complex organic molecules similar to what may have formed some of the earliest building blocks of life.

And that’s not all.

They go on to state that because this signature is found throughout our galaxy (and others) it is probable that these complex molecules are not only more common than we think – but that they arise directly from the life style of stars themselves, which of course goes a long way towards explaining how life was able to arise so rapidly after the formation of the Earth  –  and suggests a rather more ‘intimate’ connection to our night-time stellar companions than we are normally able to admit. Or in their words:

“The presence of insoluble organic matter in meteorites is evidence that complex organic solids form in nature with no difficulty. The fact that insoluble organic matter and circumstellar dust have similar chemical structures offers the possibility that Solar System organics may have a stellar connection”

But they don’t know HOW stellar systems might be able to do this.

That, is a mystery we have yet to solve – one that resonates back to the very origins of our species and life itself.

Oh and for your monthly dose of Carl Sagan – here’s the latest in the Sagan Series. Enjoy,  I certainly did.

Reference

1) Sun Kwok & Yong Zhang “Mixed aromatic-aliphatic organic nanoparticles as carriers of unidentified infrared emission features” Nature doi:10.1038/nature10542