Guider to Celestial Bodies in the Solar System

The Solar System is an assemblage of various celestial bodies which also include the Earth. It was formed around 4.5 billion years ago from the remains of the gravitational collapse of an interstellar cloud. More than 99% of these remains, however, are forming the mass of the Sun which is in the centre of the Solar System and orbited by all sorts of celestial bodies which include:

Planets. The Sun is orbited by 8 planets. 4 are classified as inner or terrestrial planets. Besides Earth, terrestrial planets (because they are mostly composed of rock and metal) also include Mercury, Venus and Mars. The 4 outer planets are also called giant planets with two - Jupiter and Saturn - being defined as gas giants and the other two planets - Neptune and Uranus - being classified as ice giants. This is because they are largely composed of ices like methane, ammonia and water. In contrast, the two gas giants are made up almost exclusively of hydrogen and helium. All planets orbit the Sun in almost perfect circle, while their orbits are located within what is known as ecliptic.
Minor planets. Like their name suggests, they are smaller than planets. The so-called dwarf planets such as Pluto are only one of several ‘categories’ of minor planets which basically encompass all celestial bodies other than comets (and planets). Minor planets thus also include asteroids, centaurs, trojans, objects in the Kuiper belt and other astronomical objects that aren’t comets or planets. To date, nearly 700,000 minor planets have been archived.
Meteoroids. They are small celestial bodies, usually smaller than asteroids as they are only up to a few metres in diameter. Consisting of metal or rock, meteoroids are fragments of other celestial bodies such as asteroids and comets but they can also be debris of planets, moon and other larger objects that was ejected into space upon their collision with other astronomical objects.
Comets. Comets are small icy celestial bodies that orbit the Sun. As they approach the Sun, they may outgas, that is sublimate, which results in what is known as tail or coma. To date, over 5,000 comets have been identified with new ones being discovered on a regular basis. Most of them originate in the Kuiper belt and Oort cloud, a cloud of icy astronomical bodies in the outermost Solar System.
Moons. Moons are natural satellites which don’t directly orbit the Sun but rather indirectly by orbiting planets, dwarf planets and possibly even asteroids and other bodies such as Kuiper belt objects. To date, 181 moons of varying sizes have been identified in the Solar System, with the largest ones such as the Jupiter’s Ganymede reaching the size of a smaller planet.