Worlds in Eruption

Could similar volcanism be found on Jupiter’s other large moons, Europa, Ganymede and Callisto? These moons do undergo tidal heating, but to a lesser extent, as they lie at greater distances from Jupiter where gravitational forces are weaker. The answer may lie in recent images from the Galileo spaceprobe, currently in orbit around Jupiter. They show evidence for a bizarre form of icy volcanism on Europa and Ganymede. This ‘cryovolcanism’ involves slushy, oozing ices and brines driven to the surface by interior heat. These moons might also suffer more dynamic eruptions, with geysers spraying fluid high into a jet-black sky.

Moving yet further afield, the Cassini spaceprobe, currently en route to the ringed world Saturn, may find volcanism on the many moons which circle this gas giant. Voyager 1 and 2 sped past Saturn with only hours to image the surfaces of the planet’s moons. Like Galileo at Jupiter, Cassini will enter orbit around Saturn and repeatedly encounter a selection of satellites. Who knows what volcanic features its sharp-eyed cameras may bring into focus?

Cosmic perspective

The new technology that permits planetary exploration has expanded the science of volcanology far beyond the well-worn terrestrial field localities of Hawaii and Iceland - the cradles of volcanic research. Spacecraft have shown that similar kinds of volcanoes, and also more exotic styles of volcanism, occur throughout the Solar System.

If we are to fully understand the geological processes that have shaped our dynamic planet - and others beyond it - we must be prepared to go looking for the answers. Fortunately we stand at a revolutionary time, a time where rapid advances in technology provide us with the means to search, to unravel and eventually to understand why worlds erupt.

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Video: Supervolcanoes [Firstscience presents]
For the last 30 years scientists have been investigating where the next supervolcano could erupt. Their research has revealed that an active supervolcano exists under Yellowstone National Park.