A group of astrophysicists says they’ve accidentally stumbled upon a “possible hint” of life on Venus: an “unexplained” chemical that could indicate the presence of anaerobic bacteria or even ongoing activity associated with specific chemical processes.
Live Science reports that the team was trying to get a “baseline” read for phosphine from a planet — Venus — not thought to have phosphine in its atmosphere. After all, the surface temperature of Venus is thought to be somewhere above 880 degrees Fahrenheit — the melting point of lead — and its atmosphere is more than 96% carbon dioxide, conditions considered inhospitable for most life forms.
“Venus has not previously been considered a likely site for life in this solar system, so scientists had yet to explore such questions with the same level of resources devoted to hunting for signs of life on Mars. The hot, almost Earth-size planet with its toxic atmospheric chemistry destroys even the hardiest robots within minutes,” Live Science notes.
“But unexpectedly,” the researchers wrote in their study released this week, “our initial observations suggested a detectable amount of Venusian PH3 was present.”
“Travel high into the atmosphere, where it’s cooler, and you’ll find more bearable, even comfortable, temperatures, closer to what we experience on Earth,” The Atlantic adds. “This is where the telescopes detected the signature of phosphine. But Venus’s atmosphere is so acidic, with clouds made of droplets of sulfuric acid, that any phosphine would be quickly zapped. For the gas to stick around, something must replenish the supply.”
Even though there may be phosphine present in Venus’ atmosphere, researchers caution that it’s far too early to know whether that chemical is the result of some sort of biological process associated with some life form. It is, however, evidence of some phenomenon worthy of further investigation.
“Phosphine on Venus doesn’t necessarily mean life on Venus, the authors wrote,” Live Science notes. “[The researchers] raised the possibility of life because bacteria are the only known way of making phosphine on a planet without a gas giant’s super-high atmospheric pressures. But it’s just as possible that some previously-unknown chemical process is producing the gas.”
“This could be unknown photochemistry [chemical reactions that require light] or geochemistry, or possibly life,” the researchers wrote. “Information is lacking — as an example, the photochemistry of Venusian cloud droplets is almost completely unknown.”
“As crazy as it might sound, our most plausible explanation is life,” one of the study’s lead authors, molecular astrophysicist Clara Sousa-Silva told The Atlantic.
That said, this is not the first time researchers have suggested life could be present in the solar system on a planet other than Earth. Mars, for instance, shows signs of once having liquid water — an environment tailor-made for some micro-organisms.
Researchers at NASA are still looking for evidence of life on Mars, past and present. Probing further into the mystery of phosphine on Venus, though, may prove more difficult than the search for life on Mars, an effort conducted with the help of robots, like the Mars rover, and satellites that collect data from the Martian atmosphere.