And Pluto will begin to share her secrets with us. When she does, as with Ceres, our familiarity with Pluto will help us recognize that Pluto is, was, and has always been a planet, albeit a small one.

In 1802, the great astronomer William Herschel suggested that Ceres and Pallas and any other smaller solar system objects should be called asteroids – meaning star-like.

Ceres is the largest object in the asteroid belt, and NASA’s Dawn spacecraft will arrive at this dwarf planet on March 6, 2015. Pluto is the largest object in the Kuiper belt, and NASA’s New Horizons ...

He named it Ceres, after the patron goddess of Sicily, where he lived. The disappointed Germans kept looking and in 1802 found another one, which was soon called Pallas.

In 1802, the great astronomer William Herschel suggested that Ceres and Pallas and any other smaller solar system objects should be called asteroids – meaning star-like.

You might argue that Ceres, Juno, Pallas, and Vesta were unfairly demoted from planet. After all, Ceres is 20% the diameter of Mercury, so it's in the planetary ballpark at least.

In 2006, the International Astronomical Union (IAU) famously demoted Pluto to a dwarf planet. Things have been a bit of a mess since then — so is it time to redefine the planet?

Ironically Pluto’s loss in this matter turns out to be Ceres’ gain, as the latter object also satisfies the defined characteristics of a dwarf planet.

Not long after the discovery of Uranus, astronomers discovered additional wandering objects – these were named Ceres, Pallas, Juno and Vesta. At the time they were considered planets, too.

Protoplanets such as Pallas - and Ceres and Vesta - can thus serve as a fossil record for an important time in our solar system's development.

When astronomers realized that Ceres had many "relatives" in roughly the same region of the solar system, they began calling them asteroids or minor planets. But as you can see in the table at the ...