The family of the sun obtaining eight planets and their satellites, asteroids, comets, etc. is solar system. our solar system consist of eight planets, satellites, asteroids, comets etc. They all are moving in the space along with sun. The sun is medium sized star having the surface of about 5400 degree Celsius. Our sun reside at the center of the solar system. The source of heat of the sun is the thermonuclear fusion reaction. In this process two or more light nuclei combine to form a single heavy nucleus. In the sun, hydrogen gas is converted into helium gas and a vast of energy is produced.
The earth is only planet where the living beings exist due to favorable conditions like suitable temperature, presence of life supporting gases and water.
The planets revolve around the sun in their elliptical orbits. During their motion, they are at different times from the sun and their speed is also different. The nearest planet mercury has one surface very hot and other surface very cold. It is due to this has no atmosphere. Venus is very hot and has small amount of oxygen in its atmosphere. Though the environment of the mars is similar to that of earth, no life is found to exist there. The planets from Jupiter to Neptune are very cold so there is no possibility of life in these planets.
The international Astronomy Union 2006 A.D has decided to displace the pluto from the status of planet to dwarf planet because pluto is very small as compared to the average size of other planets. similarly the orbit of the pluto coincides with the orbit of Neptune.