Dwarf planet Ceres was first observed 215 years ago

The dwarf planet Ceres was first discovered 215 years ago and over the generations our knowledge of the diminutive planet has has grown exponentially. Italian astronomer Giuseppe Piazzi first viewed Ceres through a telescope and 215 years later, we have a spacecraft in orbit around the planet. NASA's Dawn mission arrived at Ceres in 2015.

"When Piazzi discovered Ceres, exploring it was beyond imagination," Marc Rayman, mission director and chief engineer for Dawn at NASA's Jet Propulsion Laboratory, said in a statement. "More than two centuries later, NASA dispatched a machine on a cosmic journey of more than 3 billion miles to reach the distant, mysterious world he glimpsed."

Piazzi's first observation of Ceres was made on January 1, 1801 and when that observation was made the astronomer didn't know what he was looking at. What he knew was that the object had changed position slightly when observed the following night. His first idea of what he was looking at led him to believe he had discovered a comet.

Piazzi wrote to a fellow astronomer of his era called Barnaba Oriani, "I have presented this star as a comet, but owing to its lack of nebulosity, and to its motion being so slow and rather uniform, I feel in the heart that it could be something better than a comet, perhaps."

Later the orbit of Ceres was found to be circular, different form the orbit of a comet. By the spring of 1801, Ceres had moved so close to the sun that it was unobservable and Piazzi published his data under pressure from fellow astronomers who feared that Ceres might be lost in the dark skies. Ceres was spotted again in December 1801 by an astronomer called Franz Xaver von Zach using a mathematical projection from mathematician Carl Friedrich Gauss.

Fast-forward 215 years and we know much about Piazzi's dwarf planet. NASA has taken images that Piazzi could not even dream of giving us a look at the dwarf planets craters and other surface features. NASA has also come up with a likely reason the planet has bright spots that puzzled scientists for a time, those bright spots are believed to be salt. NASA has also been trying to determine how the single lonely mountain on the surface of Ceres was formed. The Dawn spacecraft will continue to survey the dwarf planet and scientists will continue to learn about Ceres. Who knows what discoveries might be made in the next 215 years.

SOURCE: space.com