Dwarf Planets

Definition: Dwarf planets are celestial bodies that orbit the Sun, are massive enough for their own gravity to pull them into a nearly round shape, but have not cleared their orbital neighborhood of other debris. This last point is the key difference between a dwarf planet and a regular planet.

Location: Most known dwarf planets reside in the Kuiper Belt, a region beyond Neptune populated by icy bodies. Ceres, however, is located in the asteroid belt between Mars and Jupiter.

Size and Mass: Dwarf planets are smaller than planets, but they are still substantial in size and mass compared to asteroids and comets. They are massive enough for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, but not massive enough to clear their orbital neighborhood.

Composition: Dwarf planets are typically composed of a mixture of rock and ice, with varying proportions depending on their location and formation history.

Ongoing Research: Dwarf planets are a subject of ongoing research, and new discoveries and insights are constantly being made. Missions like NASA's New Horizons flyby of Pluto have significantly expanded our understanding of these fascinating objects. Further study helps us understand the formation and evolution of the solar system.