Astronomers seeking space volcanoes

CAMBRIDGE, Mass., Sept. 7 (UPI) -- U.S. scientists studying planets outside the solar system say they think they could spot volcanoes on the distant worlds by their atmospheric signature.

Although astronomers are at least a decade away from being able to capture images of the surface of an exoplanet, they have been able to detect the atmospheres of gas giants dubbed "hot Jupiters," and any volcanic gases detected in those atmospheres could tell researchers something about the underlying surface, scientists at the Harvard-Smithsonian Center for Astrophysics said Tuesday.

"You would need something truly earthshaking, an eruption that dumped a lot of gases into the atmosphere," Smithsonian astronomer Lisa Kaltenegger said. "Using the James Webb Space Telescope, we could spot an eruption 10 to 100 times the size of Pinatubo for the closest stars."

The 1991 eruption of Mount Pinatubo in the Philippines spewed about 17 million tons of sulfur dioxide into the stratosphere, the layer of air 6 miles to 30 miles above Earth's surface.

Sulfur dioxide from a very large, explosive eruption is potentially measurable because a lot is produced and it is slow to wash out of the atmosphere, Kaltenegger said.

"Our first sniffs of volcanoes from an alien Earth might be pretty rank!" Kaltenegger said. "Seeing a volcanic eruption on an exoplanet will show us similarities or differences among rocky worlds."