Has microbial life been found on Venus?
Most of us are familiar with this quote from Sir Arthur Conan Doyle, who created the character Sherlock Holmes:Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.
Those words might be apropos this week, as scientists announce an incredible discovery: tentative evidence for microbial life within the atmosphere of Venus.
As space fans know, Venus at its surface is scorching and inhospitable, hot enough to melt lead. It’s one of the last places you’d expect to find any kind of life. But the hints of tiny Venusian microbes come not from the planet’s surface, but rather from its atmosphere, where conditions can be reasonably Earth-like.
It should be noted that this new discovery is not yet proof of life on Venus. But the researchers make a compelling case.
The exciting findings come from scientists in the U.S. and U.K., at the Massachusetts Institute of Technology (MIT), Cardiff University, University of Manchester and others. Jane Greaves of Cardiff University led the study. The Royal Astronomical Society (RAS) provided an online press briefing for journalists via Zoom last week, with three of the researchers there to discuss results. The RAS also issued a news release. The scientific were published in the prestigious, peer-reviewed journal Nature Astronomy today, September 14, 2020.
For as long as we’ve known about conditions on the planet Venus, thanks in large part to visiting space probes, Venus has always been considered one of the least likely places to support life as we know it. With scorching temperatures hot enough to melt lead and crushing air pressure at the surface – not to mention large amounts of sulfuric acid in its clouds – Venus is far from welcoming.
Some scientists, however, have speculated that life might be possible higher up in the atmosphere, where temperatures and pressures are Earth-like in a temperate zone. It is in this zone that scientists made the discovery.
What did the researchers find?
Simply put, they found a gas in Venus’ atmosphere that should not be there and that, on Earth, is considered a conclusive biosignature. It’s a very stinky gas called phosphine. As far as scientists know, there are only two ways to produce phosphine, either artificially in a lab, or by certain kinds of microbes that live in oxygen-free environments. Since there aren’t any alien labs on Venus (that we know of), that leaves microbes.
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Source: https://earthsky.org/space/life-on-venu ... signatures
Personally, I think this is an exciting discovery: to know that we now have some rather strong evidence of life existing outside of our own planetary home, the Earth. To be sure, it must be underscored that this isn't irrefutable proof of life — we simply know of no other explanation for this gas, phosphine, appearing in the atmosphere of a terrestrial (rocky) world like Venus, especially in the quantities that were observed. Scientists are thus at work trying to rule out alternative explanations, so we may be disappointed yet. As another article from National Geographic takes care to mention, there is a possibility of the detection itself being an error:
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Still, John Carpenter, an ALMA observatory scientist, is skeptical that the phosphine observations themselves are real. The signal is faint, and the team needed to perform an extensive amount of processing to pull it from the data returned by the telescopes. That processing, he says, may have returned an artificial signal at the same frequency as phosphine. He also notes that the standard for remote molecular identification involves detecting multiple fingerprints for the same molecule, which show up at different frequencies on the electromagnetic spectrum. That’s something that the team has not yet done with phosphine.
“They took the right steps to verify the signal, but I’m still not convinced that this is real,” Carpenter says. “If it’s real, it’s a very cool result, but it needs follow-up to make it really convincing.”
Sousa-Silva agrees that the team needs to confirm the phosphine detection by finding additional fingerprints at other wavelengths. She and her colleagues had planned such observations using the Stratospheric Observatory for Infrared Astronomy, a plane-mounted telescope, and with NASA’s Infrared Telescope Facility in Hawaii. But COVID-19 got in the way, and the team’s attempts have been put on hold.
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Source 2: https://www.nationalgeographic.com/scie ... sphine-gas
But would 2020 really be complete without there also being Aliens, albeit microbial ones, in the spotlight? What say ye, NSG?
An addendum: some might point out that phosphine also appears in the atmosphere of gas giants like Jupiter, but these types of planets are not strictly comparable to terrestrial ones when it comes to the occurrence of this gas. Venus lacks the very high temperatures (even if the planet is a hellhole) and pressures required to form it naturally, at least by any means which we currently know of. Aside from that, on Earth is it normally produced in laboratories or by certain bacteria and decaying organic matter.
