Complex Organic Compounds in Space
October 27, 2011 Leave a comment
Researchers have discovered that stars are capable of creating more complex organic compounds than previously thought possible. This ties in pretty nicely with the previous post, since it’s thought that asteroids may have brought organic compounds to Earth and played a role in the origin of life.
The researchers investigated an unsolved phenomenon: a set of infrared emissions detected in stars, interstellar space, and galaxies. These spectral signatures are known as “Unidentified Infrared Emission features”. For over two decades, the most commonly accepted theory on the origin of these signatures has been that they come from simple organic molecules made of carbon and hydrogen atoms, called polycyclic aromatic hydrocarbon (PAH) molecules. From observations taken by the Infrared Space Observatory and the Spitzer Space Telescope, Kwok and Zhang showed that the astronomical spectra have features that cannot be explained by PAH molecules. Instead, the team proposes that the substances generating these infrared emissions have chemical structures that are much more complex. By analyzing spectra of star dust formed in exploding stars called novae, they show that stars are making these complex organic compounds on extremely short time scales of weeks.
Not only are stars producing this complex organic matter, they are also ejecting it into the general interstellar space, the region between stars. The work supports an earlier idea proposed by Kwok that old stars are molecular factories capable of manufacturing organic compounds. “Our work has shown that stars have no problem making complex organic compounds under near-vacuum conditions,” says Kwok. “Theoretically, this is impossible, but observationally we can see it happening.”
I like how this can be seen as an astronomy, physics, chemistry or evolutionary biology discovery, depending on your focus. It may really be all of them. The idea of stars creating (relatively) complex organic compounds is pretty crazy, and will definitely fuel the idea that life probably developed elsewhere in the universe as well as here.
To be clear, the compounds they’re talking about are not anything on the scale of proteins or genetic material, but simpler molecules than those are enough to form a membrane, which is a prerequisite to life as we know it (since you need an “inside” of a living thing and an outside). There’s a manned mission to an asteroid coming up in the near future; maybe we’ll find something totally unexpected?