Free Astronomy Magazine November-December 2017

4 SOLAR SYSTEM Even in astronomy, many things are taken for granted, except that later they have to be thought through again, proving that a theory that seemed to explain something so well is quite open to discus- sion, when it isn’t downright wrong. Are we sure that the asteroids in the main belt have been there since the birth of the solar system? Until recently, yes, but no longer... Another orig the asteroid by Michele Ferrara NOVEMBER-DECEMBER 2017