Researchers from the University of California, Riverside (UCR) have identified a new potential biosignature that may help in the search for life on other planets.
According to a press release by the university, the researchers pointed at a process called methylation that many plants – such as broccoli, for example – and microorganisms use to expel potential toxins from their bodies, by turning said toxins into gases.
“Methylation is so widespread on Earth, we expect life anywhere else to perform it,” said UCR planetary scientist Michaela Leung, co-author of the new study published in the Astrophysical Journal. “Most cells have mechanisms for expelling harmful substances.”
The researchers therefore argue that, if the presence of gases produced by methylation is detected on other planets, it may hint at the existence of life on these worlds.
One particular gas produced via methylation, methyl bromide, caught the researchers’ eye for several reasons, one of them being the fact that the gas in question remains in the atmosphere for a shorter time than other 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 explained.
She also pointed out that there are “limited ways” to produce methyl bromide through “non-biological means”, so “it is more indicative of life if you find it.”
While methyl bromide is somewhat hard to detect in Earth’s atmosphere, despite being rather common, due to the intensity of the UV light emitted by our sun, the researchers concluded that this gas would be more easily detectable around an M dwarf star, the press release notes.
“An M dwarf host star increases the concentration and detectability of methyl bromide by four orders of magnitude compared to the sun,” Leung said.
Eddie Schwieterman, UCR astrobiologist and leader of Leung’s research group who co-authored the study, also said they believe methyl bromide is “one of many gases commonly made by organisms on Earth that may provide compelling evidence of life from afar.”
“This one is just the tip of the iceberg,” he stated.