Free Astronomy Magazine July-August 2015

PLANETOLOGY last stretch of its long journey, which would have taken it to Ceres, the mission’s long-awaited and final destination. This dwarf planet is 950 km across (compared to Vesta’s 590 km), and by itself accounts for about a third of the entire mass of the main asteroid belt. Most likely, Ceres would have become a real planet if the gravitational perturbations of the emerg- ing Jupiter had not intervened to stop its growth by causing havoc in the orbits of the material blocks aimed at making it visible light near infrared thermal infrared T he two sets of images on the right show two different bright regions of Ceres, recorded by Dawn on last 19 Febru- ary. The area later found to be com- posed of distinct groups of white spots is the one circled in black. [NASA/JPL-Caltech/ UCLA/ASI/INAF] Below, an example of the increased image definition, as a result of the chan- geover from the first to the second orbital altitude. In the first image are already clearly visi- ble the mysterious bright spots. [NASA/ JPL-Caltech/UCLA/ MPS/DLR/IDA]