What is the difference between a dwarf planet and a planet?

The International Astronomical Union (IAU) defines a planet as a celestial body that orbits the sun, is spherical in shape, and has cleared its orbit of debris. A dwarf planet, on the other hand, is a celestial body that orbits the sun and is spherical in shape but has not cleared its orbit of debris. This means that dwarf planets share some characteristics with planets, but they also differ in important ways.

There are currently five officially recognized dwarf planets in our solar system: Ceres, Pluto, Haumea, Makemake, and Eris. Pluto is perhaps the most famous of these, having been reclassified from a planet to a dwarf planet in 2006. Despite this change, dwarf planets are still important objects to study, as they can provide insight into the formation and evolution of our solar system.

While the distinction between planets and dwarf planets may seem arbitrary, it is an important one for astronomers to make. By defining these terms and applying them consistently, astronomers can better understand the objects in our solar system and beyond.