Dwarf planets are too small to be considered as a full-fledged planet and too large to fall into other smaller categories. There are five dwarf planets in our solar system: – Ceres, Pluto, Eris, Makemake, and Haumea. All of them are officially recognised. Ceres is closest and Eris is the furthest to the Sun. Ceres is also the smallest dwarf planet and Pluto is the largest one.
Ceres: – It is the earliest known dwarf planet. Ceres was discovered by the Sicilian astronomer Giuseppe Piazzi in 1801. The diameter of this dwarf planet is only 950 km. It has a nearly round body. It has a rocky surface and may have water ice beneath its crust.
Pluto: – Pluto was discovered in 1930 by American astronomer Clyde Tombaugh. It was classified as the ninth planet until it was reclassified as a dwarf planet in 2006. It has a diameter of 2,372 km. The International Astronomical Union decided to demote it from planet to dwarf planet.
Eris: – Eris is the second largest dwarf planet. At the time of discovery, it was thought to be the largest. It takes 557 years for Eris to orbit the Sun. It has a diameter of 2,326 km. It has a very erratic orbit that crosses Pluto’s orbit and nearly intersects Neptune’s.
Haumea: – Haumea is different from other dwarf planets as it has ellipsoid shape. It rotates on its axis every four hour. It has a diameter of 1,960 km – 1,518 km x 996 km. It also has a red spot and a layer of crystalline ice. Haumea is the only object in the Kuiper Belt other than Pluto to have more than one moon.
Makemake: – Makemake is also different from all other dwarf planets as it is the only one that lacks a satellite. It has a diameter of 1434 km x 1422 km.