Analysis of the data collected by the automatic interplanetary station “Juno” during the flyby, the largest of Jupiter’s moon Ganymede at the end of last year, showed that the water ice in its polar regions is amorphous, not crystalline structure. It is assumed that the responsible is the magnetosphere of Ganymede, reported on the website of the jet propulsion Laboratory of NASA.
Ganymede is one of the Galilean moons of Jupiter, is the largest and most massive moon in the Solar system. It is heavier than the moon twice, a little larger than mercury and has a number of interesting properties. It is the only moon in the Solar system with a magnetosphere, the occurrence of which a responsible liquid core. In addition, it has a tenuous atmosphere and ionosphere, its rotation synchronized with the rotation of Jupiter, and the surface is covered with craters and a network of grooves and ridges that is indicative of collisions with other bodies and tectonic activity.
December 26, 2019, in the course of the next close flyby of Jupiter, the interplanetary station “Juno” was a hundred thousand kilometers from Ganymede and was able to spend observing them in the infrared range using the JIRAM (Jovian Infrared Auroral Mapper), first making a map of the North pole of the satellite. Usually JIRAM is used to study the deep layers of clouds on Jupiter, but it is suitable for studying the moons of Jupiter. Station during rendezvous with the Ganymede was able to get three hundred images of its surface with a resolution of 23 kilometers per pixel.