Do You Smell That? … It’s Broccoli Gas

For as long as we’ve gazed up at the heavens and attempted to count the stars, that often posed, age-old question has continued to linger in the minds of our scientists and our SF authors …

Is There Life On Other Planets?

Some say yes, without question, but others … they’re still sniffing out that irrefutable proof. And now scientist have a new tool in the search for life on other planets … broccoli gas.

Broccoli, along with other plants and microorganisms, emit gases to help them expel toxins. Scientists believe these gases could provide compelling evidence of life on other planets.

In a process called methylation, plants, microorganisms, and … yes, broccoli, expel toxins in a gas form. These gases are made when organisms add a carbon and three hydrogen atoms to an undesirable chemical element and well … let it rip.

So, what does any of this have to do with finding life on other planets?

While this colorless (and blessedly odorless) gas floats safely away into the atmosphere, some are left contemplating a new question … what if using telescopes, researchers could detect these same gases in the atmosphere of another planet? A planet with life—that passes gas.

Pull My Finger

Other gases have previously been targeted in the search for life outside our green-and-blue marble, but one type of methylated gas—methyl bromide—has several advantages over those old, stinky gases.

These possible advantages have been explored and quantified in a study recently published in the Astrophysical Journal by Michaela Leung, a UCR planetary scientist

One of those advantages is that: methyl bromide remains in the atmosphere for a shorter time than traditional biosignature gases. “If you find it, the odds are good it was made not so long ago — and that whatever made it is still producing it,” Leung said.

Another advantage: methyl bromide is more likely to have been made by something living than a gas like methane, which can be made by microbes. But it could also be a product of a volcano or other geologic process. “There are limited ways to create this gas through non-biological means, so it is more indicative of life if you find it,” Leung said.

Now, let’s add one more advantage to ye’ old methyl bromide search. Leung’s study also determined this particular whiff of gas would be more easily detectable around an M dwarf star than it is in this solar system or ones like it. M dwarfs are smaller and cooler than our sun, and they produce less of the type of UV radiation that leads to the breakup of water. Leung says, “An M dwarf host star increases the concentration and detectability of methyl bromide by four orders of magnitude compared to the sun.”

The hope going forward is that astrobiologists will consider methyl bromide in future missions and begin planning for the capability of telescopes set to launch in the coming decades to search for new planets and other life by utilizing these gases.

“We believe methyl bromide is one of many gases commonly made by organisms on Earth that may provide compelling evidence of life from afar,” said Eddie Schwieterman, UCR astrobiologist, study co-author and leader of Leung’s research group. “This one is just the tip of the iceberg.”

And so we have it … broccoli gas … giving us a reason to be optimistic about the search for intelligent gassy life elsewhere. 😉


Head over to Galaxy’s Edge Magazine to check out September’s issue and read for free before those stories head into the archives. ♥