ONE of our nearest galactic neighbours is playing host to the building blocks of life. The Large Magellanic Cloud appears to contain methanol and other organic compounds in its star-forming regions. Here, protostars are sparking to life and sending out the most complex molecules ever detected outside our galaxy.
鈥淭his enriched material is incorporated into the disc where the planets form, and into comets and asteroids, the leftovers from the planetary system formation,鈥� says at NASA鈥檚 Goddard Space Flight Center in Maryland, who led the study.
Her team found clouds of methanol, methyl formate and dimethyl ether (The Astrophysical Journal Letters, ). All these would have been in the 鈥減rebiotic soup鈥� believed to have gone on to become life on Earth.
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We think of stars as cauldrons of plasma, but their protostar stage is colder. The core of a protostar begins amassing clouds of dust and debris. At a certain point, this is enveloped by an icy mantle often made of organic molecules and other materials.
The complex molecules in the Large Magellanic Cloud (LMC) are likely to be the remnants of these icy mantles being expelled into orbit around their protostars, says Sewilo. The LMC is a fairly primitive galaxy. It is filled with lots of dust, but didn鈥檛 form stars until about 5 billion years ago. Interactions with the Milky Way and a glancing blow with another satellite galaxy kick-started this process.
鈥淚f the production of these chemicals is common in the Large Magellanic Cloud, it could also be elsewhere鈥�
The organics are made of simpler elements like carbon, hydrogen and oxygen that are probably formed in the first few generations of stars. These stars are 鈥渕etal poor鈥�, meaning there are few heavier elements in their hydrogen-helium atmospheres. This may indicate that the complex organic compounds that were detected formed early on in the universe, just after some of the first stars sprang to life and then died. The initial results show that these compounds are in particular regions, but the team hasn鈥檛 investigated other star-forming areas of the galaxy.
鈥淲e need to see if complex organic molecules are common or if there is something special about the star-forming region where we found them,鈥� says Sewilo. If this chemical production turns out to be abundant in the LMC, it may also be widespread elsewhere.
鈥淚n the context of galaxy evolution, our current theories say that early galaxies would be more like the Large Magellanic Cloud,鈥� says at the European Southern Observatory in Chile. So, the building blocks of life may form early and often, across the cosmos. Indeed, there is evidence of other organic compounds, including amino acids, in distant galaxies.
Sorting out how these molecules form could even provide clues about our origins. And we have a perfect laboratory, just 160,000 light years away.
This article appeared in print under the headline 鈥淧re-life molecules found floating in nearby galaxy鈥�
