If We Can Detect This Gas on Distant Worlds, It Could Mean There's Life

One of the most indicative signs of the existence of life on a planet is the emission of a gas from broccoli and other plants.

The study was done by researchers at the University of California.

Life on Earth has been associated with that gas. Plants defend themselves naturally.

Plants can gasify bromide by attaching a series of carbon and hydrogen atoms to it, which will allow it to escape into the air.

It's interesting from an Astrobiological standpoint. If it shows up in an exoplanet's atmosphere, it has several advantages over other possible biosignatures.

It has a short life in the atmosphere. This is important for exoplanet searches as it means that the gas is most likely still active. It isn't just a result of a geological event.

There are very few non-biological processes that produce the gas, and even those processes aren't usually natural.

Before being regulated due to its health effects, methyl bromide was produced in large quantities and used as a pesticide.

The second advantage is the wavelength it shares with a 'cousin' gas that is also a biosignature.

Their signatures are indicative of the existence of a biological process, and being able to distinguish between the two would make them much easier to detect from afar.

An interesting quirk about the ability to detect methyl bromide is that it would be hard to detect from far away.

It's concentration levels are high enough, but the UV light from the Sun causes water in the atmosphere to split into compounds that can't be found in Earth's atmosphere.

UV light is not a problem for stars like the Sun. There would be less UV radiation around stars like M-dwarfs, which are ten times more common than sun-like stars.

Since those M-dwarfs are some of the first places to be looked at, they may be able to see a build-up of methyl bromide.

It might take a while for such a discovery to be made. It's not possible to detect trace elements in an exoplanet's atmosphere.

Some ground-based telescopes will be able to do the job in the next few years. Astrobiologists will have to wait before they can look for this biosignature.

This article was published in the past. The original article is worth a read.