The naming of cerium helped establish a trend that started in the late 18th century of naming elements after a recently discovered planet. Uranium was first, discovered and named in 1789 by Martin Klaproth just a few years after William Herschel discovered Uranus. And then in quick succession at the start of the 19th century two more planets, Ceres and Pallas, were discovered, and the elements cerium and palladium named after them. If the names Ceres and Pallas sound somewhat unfamiliar, it’s because they only lasted forty or so years as planets before being downgraded to asteroids. The final two planetary discoveries in our solar system also have elements named after them: neptunium and plutonium, though in Neptune’s case it took nearly 100 years from the discovery of the planet to the naming of the element. Pluto was famously downgraded to a dwarf planet in 2006, and at the same time Ceres was upgraded to join it.
So what is behind the name of Ceres? Its discoverer, Giuseppe Piazzi was an Italian astronomer working in Palermo, Sicily. He named Ceres for the Roman goddess of agriculture, cereal crops and fertility as Sicily was thought to be her earthly home. Cerium was discovered independently by Jöns Jacob Berzelius and Wilhelm Hisinger in Sweden and Klaproth in Germany in 1803. It was Berzelius who named it cerium, inadvertently stealing the name from William Hyde Wollaston who had ear-marked it for the element he subsequently named palladium – he had not published his discovery quickly enough.
As September is the traditional time for harvest festivals across Britain, it seems an appropriate time to post these ears of corn for the goddess of cereal crops. Unusually, there were fields of wheat still standing until mid-September around Cambridge. Quite a contrast with last year’s early July harvest that followed the glorious weather of the first lockdown. But all is now safely gathered in.