The Minor Planets or Asteroids are small bodies, all below 1000 km in diameter. Most of them occupy the ‘Main Belt’, between the orbits of Mars and Jupiter. The first asteroid, Ceres, was discovered in 1801, and three others (Pallas, Juno and Vesta) were found between 1801 and 1807. These are known popularly as ‘the Big Four’, although in fact Juno is not even among the dozen largest asteroids. Of the entire swarm, only 3 Vesta is visible with the naked eye.