Written by: Roji Gurung - 2025013, Grade VII
Posted on: 27 September, 2020
Pluto is a dwarf planet that was discovered in 1930 A.D. by Clyde Tombaugh. It was declared as the ninth planet from the Sun. Pluto lived in the solar system for more than 75 years. But then, in 2006 astronomers discovered several other planets like Pluto, so the astronomers were forced to find out if Pluto is a planet or something else. Then after some time, they found out that Pluto is actually not a planet. Then on September 13, 2006, Pluto was reclassified with other similar planets named dwarf planets. Pluto is really smaller than Earth’s moon. It is made up of rock and ice. Even though Pluto is really small it contains more water than the earth. Pluto is a cold planet. It is a cold planet because it is 5.7 billion far from the sun. Pluto is also a dark planet as there is no source of light or heat. The temperature there is about -390 F or -230 Celsius. In Pluto, even in the day, the sky looks dark. Pluto is the largest dwarf planet in the solar system. Pluto has a thin atmosphere which is mostly made from nitrogen. Pluto has got five known moons. They are Charos, Nix, Kerberos, and Hydra. Pluto’s largest moon is Charos. Between 1979 and 1999, Pluto was closer to the sun than Neptune. After the discovery of Neptune, astronomers realized that there must be another planet on the edge of the solar system. In 1906 Percival Lowell began to search for the ninth planet called, “Planet X”. But Lowell died before the planet could be found. The project was interrupted for more than ten years. In 1429 astronomer, Clyde Tombaugh was assigned for the project. Then, on February 18, 1930, he found the planet. It was named Pluto. In 1992 many objects were found orbiting around Pluto. In 2006, the International Astronomical Union declared that an object in the solar system must have three conditions to be a planet. The conditions are one, it must orbit around the sun. Second, it must be massive to pull its own gravity. And the third one is that it must have a clean neighborhood around its orbit. But Pluto failed to meet the third condition. So, it is declared as a dwarf planet but not a planet. There are currently five dwarf planets including Pluto. The other dwarf planets are Eris, Makemake, Haumea, and Ceres.
