How alcohol is formed naturally in space

The Sagittarius B2 cloud has ten billion, billion, billion liters of alcohol floating in it. Most of it is undrinkable, but there are some of them are ethanol, which is drinkable by humans. Scientists still don't know for sure why the booze is out there, but they have a theory.

In order to get a drink on Earth, we need biological organisms. We need something capable of producing some kind of sugar, like fruits or honeys. These are complex molecules, and they need to be painstakingly formed by living things. So what are billions of gallons of it doing out in space? The Sagittarius B2 cloud is filled with billions of liters of alcohol. Some of it is methanol, the kind of thing we'd use as antifreeze, and made by simpler processes than drinking alcohol. This is the stuff that has to be boiled off when bootlegging alcohol, and during Prohibition the fact that many bootleggers either didn't know or didn't care what they were doing resulted in more than a few deaths. Some of the space-cohol is vinyl alcohol, which is also undrinkable. Some, however, is ethanol, or drinking alcohol. How did such complex molecules form in vast quantities in outer space?

Heavy atoms come from fusion in the stars. Let a big star live long enough and it can form massive quantities of very heavy atoms before blowing them across the universe in a nova. Forming the complex molecules that are alcohols is a different matter. A molecule or two might be formed by the random interactions of floating atoms in space, but not billions of gallons in large chunks.

Scientists considered that some molecules might gather on bits of dust floating in the vacuum of space. The surface of the dust might let these molecules interact and form alcohol. Fast-moving molecules might then blow the alcohol off the dust, leaving gallons of it in space. However, there wasn't any conceivable way to peel the alcohol molecule off the dust without destroying the structure of the molecule in space. Now scientists think that ice could form on the dust, trapping the alcohol. As the ice melts and evaporates, when the dust bit drifts near new star clusters, the alcohol is gently freed without getting destroyed.

Most of the ethanol out there is in gas clouds, so it's still easier to get a drink at home. It's still amazing the kind of stuff that can be formed out in space, simply because of the nearly limitless possible ways for simple molecules to get together while being put through freezing temperatures, boiling heat, and the tiny motes of dust that fly in the void.

Top Image: NASA/CXC/Penn State/L. Townsley et al.

Via BBC, Lab News, The Joint Astronomy Center, Ars Technica.