Dwarf planets compared to Earth's Moon, artwork. A dwarf planet is a planetary-mass object orbiting the Sun, but not a true planet or a satellite. They are massive enough for their self-gravities to crush them into a sphere but they have not cleared the neighborhood of other material around their orbits. Ceres, for example, orbits in the asteroid belt, I orbit shared with those of the other asteroids. All the other dwarf planets so far known are found beyond Neptune, in a region of the Solar system full of debris called the Kuiper belt. This illustration shows the five currently confirmed dwarf planets in the Solar System – as of 2018 - compared to the Earth's Moon (far left). From left clockwise they are Pluto, Haumea, Eris, Makemake, Ceres and Haumea. Haumea has an ellipsoidal shape rather than a sphere, owing to its rapid spin. |