Madrid, 26 (European press)
Io is the third largest moon of Jupiter and the most volcanically active in the Solar System. Large-scale volcanic activity occurs because Jupiter’s gravity pulls on Io, generating internal heat that pushes eruptions to the surface.
In addition to its rugged, volcanic landscape, Io’s icy surface has jagged characteristics resembling dunes and hills on Earth and Mars.
Sand dunes are hills of sand piled up by aeolian processes (due to the influence of wind). However, Io’s low-density atmosphere results in weak winds, indicating that these sand dunes were carved out by another airborne force.
On Earth, similar forces are produced when molten rock meets water, producing powerful explosions of steam.
Although there is no water in Io, the new study led by planetary scientist George MacDonald considers the widespread occurrence of sulfur dioxide frosts. It is hypothesized that slowly moving lava beneath a layer of frost creates steam jets that are dense and fast enough to move grains and form large, dune-like formations on the moon’s surface. This process is known as salting.
The study calculated that the jets are powerful enough to pack grains between 20 micrometers in diameter and 1 cm in diameter and build dunes more than 30 meters high. Their work is supported by images taken by NASA’s Galileo mission, which reveal that the dimensions of Io’s sand dunes are consistent with those seen on Earth and other worlds, Rutgers reports in a statement.
In fact, dune-like features were also observed on comet 67P and Pluto, both of which lack thick atmospheres. The work by MacDonald and colleagues Io adds to the growing list of planetary bodies with weak atmospheres in which the transport of aeolian sediments may serve as an important examination of landscape evolution.