Free download or read online General Knowledge Book “Hamari Kainat (Our Universe)” an about space in Urdu and English languages.Our solar system is the one we know the most about. The Sun is at its centre. Our solar system includes everything that orbits or goes around the Sun. Planets, moons, asteroids; comets and dust are all part of the solar system. Our solar system lies near the edge of the Milky Way galaxy. The Milky Way is shaped like a whirlpool. All the stars in the galaxy, including our Sun, orbit around the centre of the Milky Way. With the discovery of Pluto in 1930, astronomers considered the Solar System to have nine planets. Pluto was classified as the ninth planet and it remained so for 75 years. But in 2006, International Astronomical Union classified Pluto as a dwarf planet due to its smaller mass. In view of this our solar system now consists of eight planets. Mercury, Venus and Earth, Mars are known as the inner planets, as they are nearest to the sun. They form a group of rocky planets. The outer planets are Jupiter, Saturn, Uranus and Neptune.