article_snippet: It's about 310 million miles from Earth and was initially classified as planet, then later demoted to an asteroid, only to be reclassified again as a dwarf planet.
article_snippet: But an asteroid was bumped up to a dwarf planet when that category was created in 2006.
article_snippet: According to the International Astronomical Union -- the group that came up with the definition -- a dwarf planet is similar to the eight main planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune) except a dwarf planet has a lot of other stuff orbiting with a dwarf planet around the sun.
article_snippet: a dwarf planet recognizes five dwarf planets: Eris, Pluto, Ceres, Makemake and Haumea.
article_snippet: a dwarf planet journey has taken a dwarf planet past Mars and on a short layover at the asteroid Vesta.
highlights_snippet: NASA's Dawn spacecraft is the first to visit a dwarf planet .