Ceres Probably Formed Farther out in the Solar System and Migrated Inward

When Sicilian astronomer Giuseppe Piazzi spotted Ceres in 1801, he thought it was a planet. Astronomers didn’t know about asteroids at that time. Now we know there’s an enormous quantity of them, primarily residing in the main asteroid belt between Mars and Jupiter. Ceres is about 1,000 km in diameter and accounts for a third …