William Herschel discovered Uranus in 1781. And Johann Galle, of the Berlin Observatory, discovered Neptune in 1846. But few people know that on January 1, 1801, the Italian astronomer Giuseppi Piazzi discovered the planet Ceres happily and silently orbiting the Sun between Mars and Jupiter. The suspiciously large gap between Mars and Jupiter had finally been filled. But astronomers rapidly determined that Ceres was much, much smaller than any other planet. Then on March 28, 1802, the German astronomer Heinrich Wilhelm Olbers discovered the planet Pallas in the same orbital zone as Ceres.
