Free Astronomy Magazine May-June 2015

PLANETOLOGY for a couple of years studied the planet and its satellites. Thanks to a series of measurements taken with the on-board in- struments, including a charged particles counter and a mag- netometer, astrono- mers discovered that Ganymede had (and it has) its own mag- netic field (the only case in satellites), in turn immersed in the immense Jupiter’s magnetosphere. The existence of a mag- netic field around that moon was essential for validating the models, and having dis- covered it was a first concrete step towards the confirmation of the existence of its L eft, a recon- struction of fantasy of the Ga- lileo probe in the Jovian system. [NASA] Below, comparison be- tween the sizes of the largest satellites of the solar system and the sizes of Mer- cury and Pluto. [NASA, Calvin J. Hamilton] instruments for a possible verification of this hypothesis, and thus the matter re- mained pending. Thereafter, in 2002, the Galileo probe visited Jupiter’s system and