Scientists analyzing data from the Large Binocular Telescope Observatory in Arizona spotted a huge lava lake on Io, one of Jupiter's largest moons.
We've known for a while that Io is quite an amazing (and hellish) place; it's the most geologically active place in the solar system, with extreme geologic activity occurring as a result of tidal friction. As both Jupiter and the other Galilean satellites - Europa, Ganymede and Callisto - tug and pull, Io's interior generates huge amount of friction, which in turn generate very high levels of volcanism. Several volcanoes produce plumes of sulfur and sulfur dioxide that go as high as 500 km (300 mi) above Io's surface. The satellite is dotted with over 100 high mountains created as a result of this extreme geology, with some of the mountains taller than Mount Everest - something remarkable for a satellite 4 times smaller than Earth.
The largest of these volcanic features is called Loki, after the Norse god of fire and chaos - and a fitting name it is. The Loki Patera depression is 202 kilometres (126 mi) in diameter, which is huge for a volcanic feature, but when you consider the distance from Earth to Io, it's almost insignificant. In fact, until recently, it couldn't be seen from Earth. But now, thanks to the Large Binocular Telescope Interferometer (LBTI), a group of astronomers was able to see it from Earth for the first time.
“We have seen bright emissions – always one unresolved spot – ‘pop-up’ at different locations in Loki Patera over the years. New images from the LBTI show for the first time that these emissions arise simultaneously from different sites in Loki Patera,” said Prof Imke de Pater of the University of California, Berkeley.
Their research confirms previous theories - that there's a massive lava lake at the Loki Patera.
“This strongly suggests that the horseshoe-shaped feature is most likely an active overturning lava lake, as hypothesized in the past.”
Team member Dr Chick Woodward from the University of Minnesota added: “studying the very dynamic volcanic activity on Io, which is constantly reshaping the moon’s surface, provides clues to the interior structure and plumbing of this moon.”
But aside from finding a massive lava lake on what should be a frozen moon, this study could have massive implications for extraterrestrial life. Io itself is not habitable, but it's the best place in our solar system to study tidal heating and tidal volcanism - which is crucial for potential extraterrestrial life on places like Europa, Saturn's moon. It also helps with some of NASA's (and other space agencies) future missions.
“It helps to pave the way for future NASA missions such as the Io Observer. Io’s highly elliptical orbit close to Jupiter is constantly tidally stressing the moon, like the squeezing of a ripe orange, where the juice can escape through cracks in the peel.”