Io, the innermost of Jupiter's four large moons, experienced four large volcanic eruptions over a two-week period in August 2013. Material from inside the satellite was ejected hundreds of miles into the air by the force of the eruptions. The low gravity on Io allowed debris to soar to much greater altitudes above Io than similar eruptions would attain on our home world.
Astronomers are questioning whether this outburst was just a one-time event, or if similar series of eruptions could be more common than once believed.
Io is a highly-volcanic world, and was the first body, other than the Earth, ever seen to exhibit active volcanoes. To this day, this world, 2,300 miles in diameter, is the only extra-terrestrial location known where hot volcanoes, like on Earth, can be found.
"We typically expect one huge outburst every one or two years, and they're usually not this bright. Here we had three extremely bright outbursts, which suggest that if we looked more frequently we might see many more of them on Io," Imke de Pater, astronomy professor at the University of California, Berkeley, said.
Previous large-scale eruptions on Io have spread tens of cubic miles of lava over hundreds of square miles of the alien landscape.
"The amount of energy being emitted by these eruptions implies lava fountains gushing out of fissures at a very large volume per second, forming lava flows that quickly spread over the surface of Io," Ashley Davies, NASA volcanologist, stated in a press release.
The Voyager 1 spacecraft offered scientists their first views of volcanoes on Io, when the first was accidentally discovered in 1979. Since that time, ground-based telescopes and observations by the Galileo observatory have revealed over 150 volcanoes on the satellite. These erupt on a regular basis, constantly re-working the surface of the Jovian satellite.
A new method of measuring magma flow from Io's volcanoes, based on spectrographic analysis, has recently been developed by Davies. Study of volcanoes on Io can assist researchers in learning more about Earth in its earliest days.
The most powerful of the recent trio of eruptions occurred on Aug. 29, 2013. All three took place over hundreds of miles, shooting curtains of flame into the sky.
The W.M. Keck Observatory in Hawaii, the Infrared Telescope Facility, operated by NASA, and the HISAKI (SPRINT-A) spacecraft, a mission managed by the Japan Aerospace Exploration Agency, witnessed the mighty trio of eruptions.
Papers describing study of the cluster of eruptions were published in the journal Icarus.
