The solar system is the name astronomers gave to the sun and all the planets that revolve round it in an elliptical orbit with their attending satellites.
The planets look like stars, but they are quite different. The word planet comes from an ancient Greek word meaning ‘wandering-star”. All the planets move round the sun in the same direction and in almost circular paths. This type of path round the sun is called orbit. The planets are nine in number and they are:
Mercury:
This is the smallest and closest planet to the sun. The mercury has no satellite of its own, but has a distance of 57, 600, 000km away from the sun. It completes its orbit once in every 88 days.
Venus
This planet is twice the distance of mercury (i.e. 107, 200, 000km) away from the sun. Venus is the second closest planet to the sun with no natural satellite. Venus is also considered as “Earth Twin” because of its proximity in size, mass and density.
Earth
This very planet is the third planet and, is often described as a “beautiful jewel”. It has one natural satellite known as the moon. The moon as a satellite to the earth revolves eastwards round the earth once in 27days. It takes the Earth about 3651/4 days to complete its orbit round the sun. The moon is 384, 629km away from the earth.
Mars
As the fourth planet, this planet is believed to have plant life, which has dark patches on its surface. The distance of this planet from the sun is about 227, 200, 000km. Mars completes its orbit in 687 days. It has two natural satellites.
Jupiter
This is the fifth and of course, the largest planet in the Solar System with about thirteen natural satellites. The surface of this very planet is very cool — 1 2& and is made up of gases like hydrogen and methane. The Jupiter has circular light and dark bands. It has a distance of about 772, 800, 000km away from the sun and completes its orbit in 12 years.
Saturn
This is the second largest planet after Jupiter. It S,4 has three rings and ten natural satellites. It is so far from the sun that it takes 291/2 years to complete its orbit round the sun. Its distance from the sun is about 1, 417, 600, 000km.
Uranus
This planet is 50 times larger than the earth and 15 times heavier than the earth too. It orbits the sun in a clockwise direction — i.e. from east to west. The Uranus has a distance of 2, 854, 400, 000km away from the sun and completes its orbit in 84 years. It has about five natural satellites.
Neptune
This planet has two natural satellites. It has a distance of 4, 468, 800, 000km away from the sun. It revolves round the sun once in 165 years.
Pluto
This is the furthest planet from the sun, and it takes 248 years to complete its revolution round the sun. Pluto as a planet is very cold and has a distance of 5, 850, 000, 000km away from the sun.