Astronomers have just found a newborn star surrounded by a cocoon of complex organic molecules – the same molecules needed to create life – far out at the edge of our Milky Way, at the extreme outer galaxy. This is the first detection of this kind and it shows that the chemistry of our Universe is really quite rich and complex in unexpected ways.

A team of researchers in Japan and Taiwan using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile were looking at a newborn star in the WB89-789 region, at the tip of our galaxy. They found it was cocooned by a rich mix of molecules that have chemical elements such as carbon (C), Hydrogen (H), oxygen (O), nitrogen (N) and sulfur (S) in them, combined in many different ways. 

These atoms are the building blocks for all life forms as we know them and, when astronomers look for life on other planets, what they’re actually looking for is gases or molecules formed by different combinations of these atoms. A molecule of water, for example, takes two atoms of hydrogen and one of oxygen – hence the H₂O of its chemical name. 

The team saw complex organic molecules such as ethanol (C₂H₅OH), methanol (CH₃OH) and propanenitrile (C₂H₅CN), for example. Molecules like these are more common in the inner regions of our galaxy, but had never been seen at the outer edges before, where the environment is quite different from that in the Solar neighbourhood.

Astronomers believe this could be because the outer parts of our Milky Way still have traces of the environment the galaxy had when it was forming, almost 14 billion years ago. Maybe chemical complexity is not something “new” in the Universe, after all – but researchers still have to find out whether this is a common trait of the outer edges of our galaxy or something rare to find. 

If one day we find this is common, what could this finding tell us about the history of the Universe and how complex molecules evolved?

Image: Artist’s concept of the protostar discovered in the extreme outer region of our galaxy

Credit: Niigata University