CLOUDS at the centre of the Milky Way are sprinkled with sugar, astronomers
have shown. They say the finding could help them home in on complex interstellar
molecules that may have given rise to life on Earth.
The chemical make-up of interstellar clouds is thought to be similar to that
of gas clouds in the vicinity of the early Earth, and could help explain how
biological molecules came to be present on Earth so soon in its history. More
than a hundred simple organic molecules, including methanol and acetic acid,
have already been found in space.
Jan Hollis of NASA鈥檚 Goddard Space Flight Center in Maryland wondered whether
interstellar clouds contain sugars. So he and his colleagues decided to look for
one of the simplest sugar molecules, glycoaldehyde. The molecule contains just
eight atoms, but can combine with others to form the sugar ribose鈥攁
building block of DNA and RNA.
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They pointed a 12-metre radio telescope on Kitt Peak in Arizona at a giant,
cold cloud of gas and dust near the centre of the Galaxy. It revealed the
characteristic radio emissions of glycoaldehyde molecules flipping from one
energy state to another. They have submitted their results to Astrophysical
Journal Letters.
The team plans to map the distribution of glycoaldehyde in galactic clouds.
鈥淭his will give us a better idea of where and how to look for more bio-molecules
like complex sugars,鈥� he says. It could eventually shed light on how much
prebiotic chemistry goes on in space.