Millennia of volcanic eruptions turned Venus into a ‘hothouse’

A recent NASA study says millennia of volcanic activity may have helped turn Venus from a habitable world into one

A recent NASA study says millennia of volcanic activity may have helped turn Venus from a habitable world into an “acid greenhouse.”

NASA/JPL image

Venus is one of the greatest mysteries in the solar system because it’s a “hell world” that NASA says was once habitable, including running water and a shallow ocean.

So what happened?

The simple answer is volcanoes, says NASA.

Eruptions started on Venus and didn’t stop even as decades became centuries and centuries became millennia, according to the recently published study “Large-scale Volcanism and the Heat Death of Terrestrial Worlds.”

“Volcanic activity spanning hundreds to thousands of centuries and the eruption of massive amounts of material may have helped transform Venus from a temperate and wet world to the acidic greenhouse it is today,” NASA said in a press release.

To understand the startling change, scientists used Earth’s history of “major mass extinction events” as a benchmark, the report said.

During such periods, “massive volcanic eruptions” of more than 100,000 cubic miles poured across the surface. “At the top end, this could be enough molten rock to bury the entire state of Texas half a mile deep,” says NASA.

It was these ancient volcanic eruptions — not rogue asteroids — that killed off much of Earth’s ancient life, scientists say.

“Contrary to popular belief, volcanism, rather than impactors (asteroids), has had the greatest impact on and bears most responsibility for large-scale mass extinction events in Earth’s history,” the report said.

“The occurrence of several such eruptions (on Venus) in a short geologic time span (within a million years) could have led to a runaway greenhouse effect that triggered the planet’s transition from wet and temperate to hot and dry. “

The average temperature on Venus is 864 degrees, one day is the equivalent of 117 Earth days, and it has a “crushing carbon dioxide atmosphere 90 times thicker than Earth’s,” says NASA. Even more tellingly, “Large fields of solidified volcanic rock cover 80% of the planet.”

Such fields are known as “great igneous provinces,” and they could be planet killers, NASA says.

“Life on Earth has endured at least five major mass extinctions since the emergence of multicellular life about 540 million years ago, each of which wiped out more than 50% of animal life across the planet,” says NASA.

“According to this study and other previous studies, most of these extinction events were caused or exacerbated by the kinds of eruptions that produce large igneous provinces. In Earth’s case, the climate perturbations resulting from these events were not enough to trigger a runaway greenhouse effect. to cause, as on Venus, for reasons… scientists are still working to determine.

The study suggests Earth has “barely” avoided the climatic effects “responsible for the heat death of our sister world Venus.”

This story was originally published November 22, 2022 3:12 PM.

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Mark Price has been a reporter for The Charlotte Observer since 1991, covering topics such as schools, crime, immigration, LGBTQ issues, homelessness and nonprofits. He graduated from the University of Memphis with majors in journalism and art history, and a minor in geology.

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