planetoit

Planetoit is a celestial body that orbits a star. Unlike planets, planetoits are not massive enough to clear their orbital path of other debris. They are generally smaller than planets and can be rocky, metallic, or icy in composition. The International Astronomical Union (IAU) established a definition for what constitutes a planet in 2006, which indirectly defined what a planetoit is not. Objects that meet the criteria of being round due to their own gravity and orbiting a star, but have not cleared their neighborhood, are classified as planetoits.

The asteroid belt between Mars and Jupiter contains numerous planetoits, such as Ceres. Ceres was once considered a planet but was reclassified as a planetoit after the IAU's definition. The Kuiper Belt, beyond Neptune, is also home to many planetoits, including Pluto, which was famously reclassified from a planet to a planetoit in 2006. These small celestial bodies offer valuable insights into the formation and evolution of planetary systems. Studying their composition, orbits, and physical characteristics helps scientists understand the early solar system and the processes that led to the formation of planets.