Essay On Heavenly Bodies

   All the Heavenly bodies like the Stars, Planets, Satellites, Asteroids, Comets, etc are called the Celestial Bodies. These bodies constitute the Universe without the Celestrial bodies the universe could not be considered because all these make up the whole universe. In August 2006, the conference of International Astronomical Unit in 1919 held at Prague,made a consensus to categorize conventional planets are the planets fulfilling the following conditions are considered as conventional planets. They must rotate around the sun. They have enough mass and because of which the Gravitational pull becomes so dominant that the shape of the bodies is considered to be spherical. One Celestial body does not intersect the revolving orbits of other Celestial bodies. 

   Example of such planets is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Since Pluto does not fulfill all the above-mentioned conditions so it has been discarded from the category of conventional planets at Prague summit of IAU held in August 2006 and kept in the category of Dwarf planets, this the total numbers of conventional planets in our solar system is now counted eight. Pluto because of its very small size and large distance from the sun, has been kept in the category of Dwarf planets by IAU in August 2006 at Prague, however, NASA has expressed as objectionable view in this regard. William Herschel discovered the planets Uranus in 1781 whereas Neptune was discovered by Johann Galle in 1846. Dwarf planets of Plutones, it is the second category of Celestial bodies which includes Plutones,i.e, Pluto, Cheron, Ceres, Xena-2003 UB313. 

   Their size is smaller than the conventional planets and they are much far apart from the sun. The diameter of Cheron is only 1192 KM. Earlier was accepted as the only Satellite of Pluto. Ceres was discovered by Italian Astronomer Piyajiin 18081. It is the largest among all the discovered asteroid. Its diameter is about 936 KM (1/5th of Mercury) Xena  UB313 also called Iris is only about 1490 mile flattened. Small celestial bodies like Asteroids, Meteors, Satellite, etc are also included in this category.