MOUNTAIN VIEW (KPIX 8) -- A team of British scientists have announced the discovery of a gas in the upper atmosphere of Venus that could be a "biomarker" for life on the planet.
The findings were published Monday in an article -- entitled "Phosphine Gas In The Cloud Decks Of Venus" -- for the the journal Nature Astronomy.
Phosphine is a colorless, flammable, foul-smelling gas that occurs on Earth when organic matter decays, like in dead fish or swamps. But it can also be man made or occur under specific geologic conditions.
The presence of a phosphine puzzled the research team led by Jane Greaves, a professor at Cardiff University in the United Kingdom.
"I was just stunned. I mean I did this as an interesting experiment. I've never really thought about detecting it," said Greaves.
Phosphine on Venus was first discovered in 2016 using the James Clerk Maxwell Telescope in Hawaii. It was subsequently confirmed using the ALMA radio telescope in Chile.
"This is very unexpected, because phosphine is a phosphorus atom and three hydrogen atoms, and there's really very little hydrogen available in the atmosphere," said Greaves. "So we think something is a process that's making it, and one of the possibilities is small floating organisms. And the reason we think that is because there are small bacteria on Earth that do actually make phosphine."
The research team spent years examining other possible sources and ruled out lightning, meteors and volcanoes, which would not create enough phosphine on the scale that was detected, about 20 parts per billion.
But the paper stopped short of making concrete conclusions, writing "…We emphasize that the detection of PH3 is not robust evidence for life, only for an anomalous and unexplained chemistry."
Nathalie Cabrol, an astrobiologist, planetary researcher and the Director of SETI Institute Carl Sagan Center for Research in Mountain View, expressed doubt about Venusian phosphine as a biomarker.
"Extraordinary claims require extraordinary evidence," said Cabrol.
Cabrol said clouds are unstable habitats for life, and that any possible life likely developed on the surface and was then transported up into the atmosphere.
However, Venus is one of the most inhospitable planets in the solar system, with a surface temperature of 900 degrees Fahrenheit, with an extremely high pressure atmosphere that is 97 percent carbon dioxide, and sulfuric acid rainstorms.
"And we don't know of anything that can survive. It becomes really hard to take something alive and then take it to the atmosphere," said Cabrol. "Science is not a religion. Science can be modified. Science can be changed in light of new evidence. I'm not saying it's not possible. I'm just saying today, that the body of evidence leans more towards a geologic process rather than biological process. But I could be wrong. And that's the beauty of science."
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