Interesting facts about dwarf planets

• A dwarf planet is a celestial body that orbits the Sun, too small to be considered a real planet but too large to be called a asteroid.
• It has to have sufficient mass to overcome its compressive strength and achieve hydrostatic equilibrium.
• The Solar System currently has 5 dwarf planets: Ceres, Pluto, Haumea, Makemake and Eris.
• The term dwarf planet was adopted in 2006.
• Ceres at first was classified as a large asteroid.
• It is suspected that at least another 40 known objects in the Solar System are dwarf planets.
• Pluto was first considered a small planet in itself.
• For almost 50 years Pluto was thought to be larger than Mercury.
• Eris was discovered in 2005 beyond the orbit of Pluto.