Two huge waves of lava wash across a volcanic crater on the surface of Io, Jupiter’s fourth largest moon, new research reveals.
Astronomers tracked the waves as they rolled across Loki Patera, a crater stretching 127 miles across Io’s surface.
The moon is the most volcanically active body in the solar system and Loki Patera is its largest volcano.
The volcano’s periodic brightening and dimming could be explained by the waves, the study suggests.
“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,” said Katherine de Kleer, a UC Berkeley graduate student and the study’s lead author.
“In this scenario, portions of cool crust sink, exposing the incandescent magma underneath and causing a brightening in the infrared,” de Kleer added.
Astronomers observed images of Io taken in March 2015 as Jupiter’s moon Europa passed in front of Io, gradually blocking out light.
Europa’s surface is covered in ice, which reflects little sunlight at infrared wavelengths, allowing researchers to isolate the heat from Io’s surface.
The data suggested the temperature of the molten lake increased from one end to another, indicating that waves sweep across it surface.
Imke de Pater, a UC Berkeley professor of astronomy, said: “This is a step forward in trying to understand volcanism on Io, which we have been observing for more than 15 years, and in particular the volcanic activity at Loki Patera.”