Can We Spot Volcanoes on Alien Worlds? Astronomers Say Yes.. / September 13, 2010 /
Volcanoes display the awesome power of Nature like few other events. Earlier this year, ash from an Icelandic volcano disrupted air travel throughout much of northern Europe. Yet this recent eruption pales next to the fury of Jupiters moon Io, the most volcanic body in our solar system.
Astronomers are decades away from being able to image the surface of an alien world, or exoplanet. However, in a few cases they have been able to detect exoplanet atmospheres for gas giants known as «hot Jupiters.» An eruption sends out fumes and various gases, so volcanic activity on a rocky exoplanet might leave a telltale atmospheric signature.
«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.»
The 1991 eruption of Mount Pinatubo in the Philippines spewed about 17 million tons of sulfur dioxide into the stratosphere a layer of air 6 to 30 miles above Earths surface. The largest volcanic eruption in recorded history, the 1815 Tambora event, was about 10 times more powerful.
«A Tambora-sized eruption doesnt happen often here, but could be more common on a younger planet, or a strongly tidally active planet analogous to Io,» said Henning. «Once you detected one eruption, you could keep watch for further ones, to learn if frequent eruptions are common on other planets.»
Due to its proximity, a hypothetical Earth or super-Earth orbiting Alpha Centauri would offer a best-case scenario for a sun-like star. A super-Earth orbiting a smaller host star close to our own Sun would show the biggest signal. But any Earth-like planet less than 30 light-years away could show faint signs of volcanism when studied with the James Webb Space Telescope.
This research will be published in The Astrophysical Journal. Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.