The Universe Yields Building Blocks of Life

Astronomers have recently made a fascinating discovery: the existence of complex organic compounds throughout the universe, despite the absence of life. As Science Daily reports:

Prof. Sun Kwok and Dr. Yong Zhang of The University of Hong Kong show that an organic substance commonly found throughout the Universe contains a mixture of aromatic (ring-like) and aliphatic (chain-like) components. The compounds are so complex that their chemical structures resemble those of coal and petroleum. Since coal and oil are remnants of ancient life, this type of organic matter was thought to arise only from living organisms. The team’s discovery suggests that complex organic compounds can be synthesized in space even when no life forms are present.

A short time ago, I posted about the vital role that stars played in creating our universe and forming the elements that led to life on Earth. As it turns out, stars are not only producing the basic elements for life – such as carbon or oxygen – but  they are also producing more complex components for organisms themselves.

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.

As the excerpt noted, stars are actually emitting this organic matter into the vacuum of space regularly. Whereas I previously thought that it was upon a star’s death, billions of years later, that such matter was ejected, it seems their releasing it as a constant by-product. Needless to say, this has vast implications for the possibility of life elsewhere in the universe, as well as for abiogenesis – how life on Earth first began.

Most interestingly, this organic star dust is similar in structure to complex organic compounds found in meteorites. Since meteorites are remnants of the early Solar System, the findings raise the possibility that stars enriched the early Solar System with organic compounds. The early Earth was subjected to severe bombardments by comets and asteroids, which potentially could have carried organic star dust. Whether these delivered organic compounds played any role in the development of life on Earth remains an open question.

One we’re closer to solving perhaps. I’ll certainly reserve my excitement pending more verification from other researchers, but this is certainly a fascinating prospect. That the building blocks of life could spontaneously – and regularly – emerge from stars all across the universe may significantly increasing the chances for life elsewhere in this universe – and perhaps finally explain why we’re all here to begin with.