article_snippet: Ceres was discovered in 1801 (Pluto wasn't found until 1930) and was the first object found in our solar system's main asteroid belt between Mars and Jupiter.
article_snippet: But Ceres seems to have lots of oddities.
article_snippet: One of the other things scientists noticed is how round Ceres is.
article_snippet: Being round is very important because it is the main characteristic of a planet -- a title that Ceres had -- then lost.
article_snippet: Ceres was demoted to an asteroid because 19th century astronomers couldn't be sure an asteroid was round.
article_snippet: But at some point, Ceres will run out of hydrazine, the fuel used to guide the spacecraft.