Pluto has been voted off the island.Pluto will now be dubbed a dwarf planet. But it’s no longer part of an exclusive club, since there are more than 40 of these dwarfs, including the large asteroid Ceres and 2003 UB313, nicknamed Xena—a distant object slightly larger than Pluto. “We know of 44” dwarf planets so far. “We will find hundreds. It’s a very huge category.”
What Is a Planet Today?
According to the new definition, a full-fledged planet is an object that orbits the sun and is large enough to have become round due to the force of its own gravity. In addition, a planet has to dominate the neighborhood around its orbit. Pluto has been demoted because it does not dominate its neighborhood. In addition, bodies that dominate their neighborhoods, “sweep up” asteroids, comets, and other debris, clearing a path along their orbits. By contrast, Pluto’s orbit is somewhat untidy.
A planet (from Ancient Greek αστήρ πλανήτης (astēr planētēs), meaning “wandering star”) is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals. Planetesimals are solid objects thought to exist in protoplanetary disks and in debris disks. The word planetesimal comes from the mathematical concept infinitesimal and literally means an ultimately small fraction of a planet.While the name is always applied to small bodies during the process of planet formation, some scientists also use the term planetesimal as a general term to refer to many small Solar System bodies – such as asteroids and comets – which are left over from the formation process. There are eight planets and five recognized dwarf planets in the Solar System. In increasing distance from the Sun, the planets are:
Mercury – Venus – Earth – Mars – Jupiter – Saturn – Uranus – Neptune