Life Might Exist in the Clouds of Venus

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The planet Venus is not usually what you’d think of as “habitable,” with its clouds of sulfuric acid and atmospheric pressure 92 times higher than Earth. The surface temperature is roughly 870 degrees Fahrenheit (465 degrees Celsius), which is hot enough to melt lead, so it’s safe to say life as we know it could not exist. However, a new study from the University of Wisconsin-Madison in the journal Astrobiology suggests there could be life on Venus. Well, not directly on it, but above the surface.

Scientists believe Venus was a very different, more Earth-like world when it was younger. However, all its water evaporated into the atmosphere as the temperature shot upward between 650 million and 2 billion years after its formation. It took microbial life about one billion years to develop on Earth, so it’s plausible some sort of life came into existence on Venus and migrated upward as conditions on the ground worsened.

The study makes a case that Venus’ atmosphere has everything microorganisms would need to survive, and they would be protected from the worst of the planet’s conditions. The temperature and pressure need to be compatible with life to have any hope of finding microorganisms high up in Venus’ choking atmosphere. According to the researchers, once you get to an altitude of 30 miles, the pressure drops to around 15 pounds per square inch—similar to sea level on Earth. The temperature is a toasty but tolerable 140 degrees Fahrenheit (60 degrees Celsius).

The composition of the Venusian atmosphere isn’t as much of a problem as you might expect. On Earth, a class of organisms known as extremophiles can thrive in volcanic vents, inside rocks, and even in pools of acid. It’s possible a hearty organism could feed on the carbon dioxide in the atmosphere and float around unbothered by the clouds of acid. In the words of Dr. Ian Malcolm, “Life, uh, finds a way.”

The surface of Venus captured by a Soviet Venera probe.

We don’t have any direct evidence of life on Venus, but the study points to an interesting possibility. Venus has dark splotches in its atmosphere that shift size and location, but never completely vanish. Scientists don’t yet have a convincing explanation for these dark patches, but the University of Wisconsin team points to research that indicates the particles in these regions are the size of bacteria. What if they actually are bacteria-like organisms?

The corrosive nature of Venus’ atmosphere makes studying the planet difficult. While we can land a rover on Mars and drive around for years, the Venus landers have lasted barely two hours at best. Perhaps in the future, high-altitude probes will be able to survive longer on Venus and find out if there really is life wafting on the breeze.