Scientists Determine Best Spots in Space for Organic Molecules

The alcohol that scientists are talking about is methanol, which is poisonous and often confused with its drinking alcohol relative: ethanol.

Finding methanol in space isn’t quite as exciting as finding ethanol, but it’s still somewhat exciting. The purpose of the study is to find locations where methanol is produced, because that will help scientists understand how complex organic molecules that are necessary for life are produced in space. Some of the study’s researchers tried to figure out the conditions under which methanol is produced in interstellar clouds and the envelopes of young stars.

Although methanol isn’t a complex organic molecule, it is still useful in the study because, as Douglas Whittet of RPI explains, “methanol formation is the major chemical pathway to complex organic molecules in interstellar space.”

Methanol is produced when carbon monoxide (CO) that is situated on interstellar dust particles reacts with hydrogen at low temperatures (somewhere around 10-15 K). Once the methanol is produced, cosmic rays, UV radiation, or small amounts of heat can induce reactions that fuse with it to create more complex molecules. All of these molecules could then wind up in the disk of dust and gases surrounding a new star and eventually become part of planets.

Examining Old Data

This study doesn’t actually demonstrate new observational data, rather it just provides a new examination of existing work. The past measurements looked at wavelengths in the infrared range, where various chemical species (i.e. methanol, water and carbon monoxide) vibrate. Methanol specifically vibrates at energy levels that correspond to several wavelengths – one for every different molecular bond. But 3.54 μm and 9.75 μm are the two easiest to examine and so they’re the most commonly used ones.

The researchers examined data from two different regions: interstellar molecular clouds and the envelope regions of young stars. They found that the area surrounding some of the young stars, around ten percent of them, hold higher-than-average quantities of methanol – up to around 30 percent of the total ice (the rest of it is mostly water, carbon monoxide, and carbon dioxide). Other areas don’t even have enough methanol to be detectable.

The team also discovered minute concentrations (a few percent) of methanol in cold molecular clouds. Methanol production seems to occur in the coldest, most dense regions of the clouds, where the carbon monoxide is almost “shielded” from becoming carbon dioxide instead of methanol.

Perfect Spot for Methanol Production

They discovered what might be a perfect spot for methanol production: when carbon monoxide accumulates at the perfect speed on the dust particles, based on the temperature and density of the local conditions. If this rate is too fast, the molecules are buried and can’t produce the methanol reaction; if the rate is too slow, the hydrogen reacts with other things and thus less methanol is produced.

So, although the researchers have yet to find drinking alcohol in space, this study is still exciting for the scientific prospects that it creates.

Photo by : NASA