Key Takeaways:
- Giuseppe Piazzi discovered Ceres in 1801.
- Initially classified as a planet, Ceres was later called an asteroid.
- In 2006, Ceres was reclassified as a dwarf planet.
- Piazzi's discovery makes him the first discoverer of a dwarf planet.
Born in 1746 in Ponte, Italy, Giuseppe Piazzi was ordained as a priest in 1769. He taught theology, philosophy, and mathematics at various points in his career, but in 1787 became a professor of astronomy, and King Ferdinand of Sicily appointed him as the director of the Palermo Astronomical Observatory. On New Year’s Day 1801, Piazzi was working on a catalog of star positions when he spotted a new object in the sky, a “light that was a little faint and colored as Jupiter.” He called it a comet, but suspected it was something more than that. When Piazzi announced the find in 1801, it was classified as a planet and named Ceres Ferdinandea; William Herschel later proposed that it and Pallas (discovered in 1802) be called asteroids. Piazzi died on July 22, 1826. Almost 200 years later, in 2006, Ceres was re-designated again, making Piazzi the first person to discover a dwarf planet.
