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Dawn spacecraft nears dwarf planet Ceres

Posted at 6:40 PM, Mar 03, 2015

“When I was your age, Pluto was a planet.”

Nearly a decade ago, Pluto was stripped of its planetary status. But if you were alive two centuries ago, you could have been just as smug about Ceres, too.

On March 6, NASA’s Dawn spacecraft will visit the dwarf planet Ceres for the first time. Did you know Ceres, like Pluto, was once considered a planet?

Ceres was first discovered in 1801 by Sicilian astronomer Giuseppe Piazzi. Astronomers at the time considered it an undiscovered planet between Mars and Jupiter. They named Ceres after the Roman goddess of harvest.

By 1803, Ceres was so popular that a new element was named after it, Cerium.

Within a year, astronomers started digging up more “planets” nearby. It turned out that Ceres was just the largest asteroid out of many. By the 1850s, Ceres was demoted to an asteroid.

Then, in 2006, the International Astronomical Union decided Pluto wasn’t a planet, either. The reasons may sound familiar — Pluto turned out to be one of many objects in an orbiting belt of rock and ice.

Pluto was demoted to dwarf planet, angering its millions of fans. In the same stroke, poor Ceres finally caught a break and was promoted on equal footing with Pluto.

When Dawn arrives, Ceres will be in the spotlight once more.

Gavin Stern is a national digital producer with the Scripps National Desk.