As researchers around the world ponder on whether life exists on other planets and how to find it if it actually does, a group of scientists from MIT and Caltech now postulate that a certain vile substance may be a sure-fire way to find answers to those questions, MIT News Office reports.
Having published the results of their study in the journal Astrobiology, the scientists argue that phosphine, which is probably one of the most stinky and toxic gases on our planet commonly found in places such as penguin dung heaps or the depths of swamps, can apparently only be produced by anaerobic organisms like bacteria or microbes, and therefore is a “pure biosignature”.
"Here on Earth, oxygen is a really impressive sign of life", said Clara Sousa-Silva, research scientist in MIT’s Department of Earth, Atmospheric and Planetary Sciences and lead author of the study. "But other things besides life make oxygen too. It’s important to consider stranger molecules that might not be made as often, but if you do find them on another planet, there’s only one explanation".
The team also determined that phosphine has no significant false positives, and that production of relatively small amounts of this gas, roughly the "equivalent to the amount of methane produced on Earth today", would create a signal in the atmosphere which could be detected at a distance of about 16 light years by advanced observatories like the upcoming James Webb Space Telescope, the media outlet adds.
Sousa-Silva also described the results of her and her colleague’s efforts as a pipeline for researchers to proceed to characterise a further 16,000 possible biosignature candidates.
"I think the community needs to invest in filtering these candidates down into some kind of priority. Even if some of these molecules are really dim beacons, if we can determine that only life can send out that signal, then I feel like that is a goldmine," she said.