Loki Patera on Jupiter's moon has been described as the most powerful and persistent active volcano in the Solar System.
A wave of fresh magma was found to be bleeding up onto the moon’s surface. The findings were made two years ago, researchers decided to take advantage of a rare astronomical event to create a detailed map of this king of volcanos.
The measurements of the geological phenomenon have only been based on a sequence of heat map images that were published by a team of astronomers led by University of California, Berkeley. The images were taken through the Large Binocular Telescope in Arizona in March 2015.
The measurements weren't taken by some probe or satellite, but by a telescope on a mountain several hundred million kilometers away.
This was helped by the ice-moon Europa passing in front of Io, which thanks to its coating of frozen water doesn't reflect infrared wavelengths, providing something of a shadow to allow the pattern of temperatures on Io's surface to stand out.
Michael Skrutskie of the University of Virginia revealed that there was so much infrared light available that they could slice the observations into one-eighth-second intervals during which the edge of Europa advanced only a few kilometers across Io's surface. Skrutskie is a researcher and developer of the infrared camera technology.
Such kinds of eclipses have been used to study Io before from far away from Earth's surface, advanced optics technology have only now allowed scientists to map hotspots down to a resolution of about 10 kilometers (6.2 miles).
Studies conducted in the past described an active volcano surrounded by a depression, or 'patera', about 200 kilometres (124 miles) across, filled with cooling rock that was resurfaced every 400 to 600 days with waves of lava that flowed around the basin at a speed of about 1-2 km (about a mile) per day.
An interesting question arose on where the fresh lava come from?
There was a possibility that the lava was the result of regular eruptions spewing out of Loki Patera itself. The second possibility was through something called overturning. As molten rock cools on the surface it increases in density, until the chilled crust collapses into the still molten rock beneath. Each collapse can make the next section unstable, creating a creeping wave of magma across the field to cool in its place.
This is exactly what is happening around the Solar System's most intense volcano. The lead researcher Katherine de Kleer, who is a graduate student from University of California, Berkeley, said that if Loki Patera is a sea of lava, it encompasses an area more than a million times that of a typical lava lake on Earth.
The variations in temperature revealed how recently magma had been exposed, telling a story about a wave of magma starting from the northwest corner of the surrounding basin, gradually moving clockwise, and a more recent wave starting further east.
The team of researchers will have to wait until 2021 until Europa aligns with Io again. Lava has been spilling and cooling around the volcano before Viking first took some snaps back in 1979, so it's unlikely to be falling quietly any time soon.
Jupiter's tidal forces massages the entire moon constantly, creating hundreds of volcanos all over its surface that channel molten rock and sulfur and send occasional plumes of dust and sulfur-dioxide gas high into its thin atmosphere.