The New Planet That Was Lost
On the first night of the 19th century, an astronomer in Palermo found a new world. Then it slipped behind the Sun and vanished. A young mathematician worked out where to find it.
What was reported
On 1 January 1801, the astronomer Giuseppe Piazzi, at the observatory in Palermo, noticed a faint star that moved from night to night. He followed it for several weeks, until it disappeared in the glare of the Sun. Astronomers feared the new planet, which he named Ceres, had been lost.
A 24-year-old German mathematician, Carl Friedrich Gauss, developed a new method to calculate its orbit from Piazzi's few observations. At the end of 1801, astronomers looked where Gauss predicted, and found Ceres again.
Explanations offered
Ceres was the first asteroid ever found, and it's now classed as a dwarf planet, the largest object in the asteroid belt. Gauss's methods became fundamental to astronomy and statistics. NASA's Dawn spacecraft orbited Ceres from 2015, finding mysterious bright spots of salt.
- When
- Discovered 1 January 1801
- Where
- Palermo Observatory, Palermo, Sicily, Italy
- Witnesses
- Giuseppe Piazzi, then Carl Friedrich Gauss
- Status
- Confirmed
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.
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