On a massive ocean planet 124 light-years from our own, sunlight from this planet’s star struck certain molecules in its atmosphere, which re-emitted the light towards Earth, where the James Webb Space Telescope “tentatively” detected its signature, as the first evidence of life other than our own. Curiously, we Earthlings seemed quite incurious about something so extraordinary. The tell-tale sign was a biosignature of dimethyl sulphide/disulphide (DMS). DMS is not just an ordinary chemical, it’s a rather astonishing chemical. On our lovely planet, it is only produced by marine phytoplankton. What’s happening on that watery world seems to be paralleling what happened here, 2.7 billion years ago.
Planet K2-18B’s atmosphere is much like Earth’s atmosphere, way back when, except containing much more hydrogen. Our distant microbe ancestors didn’t breathe oxygen, they breathed sulfur, or technically they used various sulfur compounds as an electron acceptor in anaerobic respiration. They “breathed sulfur” to produce the carbon-based proteins and enzymes needed for life. But that all changed 2.4 billion years ago, when the first microbes on our watery planet stumbled into photosynthesis, to construct “organic” carbon — sugars, lipids, proteins, and nucleic acids, from CO2, water and light. As those trillions of microbes breathed CO2, they breathed out O2 — oxygen. Over billions of years, those nasty little oxygen polluters stunk up the atmosphere, increasing the planet’s oxygen from 0% to today’s 21%. But, even at 1%, back then, it polluted the planet. It was so toxic that it destroyed most of the primitive sulfur breathers who couldn’t adapt. Today, of course, oxygen is no longer pollution, but essential to life.
The Webb telescope didn’t detect much oxygen in K2-18B’s atmosphere. But, it did “tentatively” (almost to rigorous scientific standards) detect DMS, which is likely a product of sulfur-breathing/metabolizing life. K2-18b lacks those oxygen breathers. For now, the low-life sulfur breathers are safe, on that distant watery planet. Over the next two billion years, K2-18B may well be in the news, now and then, as they evolve into higher forms of life.
NASA” src=”https://images.americanthinker.com/oq/oqjgixznrb2kr90guup8_640.jpg” width=”450″ />
Image: NASA
This article was originally published at www.americanthinker.com
