Survey Halves Estimated Population of Big Near‐Earth Asteroids

On 1 January 1801, reckoned by sticklers to be the first day of the 19th century, the Sicilian astronomer Giuseppe Piazzi discovered Ceres, the first of the asteroids. With a diameter of almost 1000 km, Ceres remains by far the largest of the known asteroids. Piazzi was searching the region between the orbits of Mars and Jupiter where Bode's law, an empirical formula of the day, said there ought to be an undiscovered planet.