About 4.5 billion years ago, a huge cloud of cosmic gas and dust banged and the solar system came into existence. The sun is a yellow star acting as the centre of our solar system. The temperature at its core is about 16 million degrees kelvin (K) and it radiates 383 billion trillion kilowatts per second. The sun's strong gravitational pull holds the earth and other planets in their places.

Mercury experiences temperature extremes, varying from 200 ° C during daytime to a frigid -400 ° C at night. Mercury is mainly composed of oxygen, sodium, and helium.

The cloudy planet of Venus has acid rain and carbon dioxide skies that hide our view of its surface. Earth has a diameter, a few hundred kilometers longer than that of Venus. The changing seasons on the earth is the result of its 23 degrees tilted rotation on its axis.

Mars is known as the "red planet" as its surface is composed of iron oxide. Olympus Mons, on the surface of Mars, is the largest known volcano in the solar system. Jupiter is called the king of planets and is twice the weight of all other planets combined. First among the gas giants, Jupiter, with more satellites than any other planet, has no solid surface except for a small rocky core.

Saturn, the second largest planet, is the least dense and flattest. Among its 31 known natural satellites, Titan is the largest. Titan is slightly bigger than Mercury. When other planets spin on an axis perpendicular to the plane of the solar system, Uranus' axis is parallel. Uranus has got a rocky core, surrounded by a huge ocean of rocky material.

Neptune is home to some of the fastest windstorms in the solar system. The great dark spot on Neptune is a large storm with a diameter the size of the earth. Pluto, 2,360 km in diameter, is a lone icy planet, the only planet not yet visited by a spacecraft. Pluto revolves around the sun once in 247.7 earth years and it rotates in the reverse direction as that of other planets.