The solar system

We are all quite familiar with the solar system. Our solar system consists of the sun and eight planets. The eight planets of the solar system are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Besides planets, the solar system consists of a large number of minor planets or asteroids, a hosts of comets and meteors. The gravitational pull (attraction) between the sun and these celestial bodies keeps all of them revolving around the Sun. 

The solar system

The sun ☀️

The solar system is dominated by the Sun, which accounts for almost 99.9% of the matter of the whole solar system. The Sun is also the source of almost all the energy in the solar system. The Earth receives almost all its energy (heat and light) from the Sun.

The sun. 

The Sun is essentially a sphere of hot gases. The temperature of the bright disc (visible), which is the source of energy for us, is about 6,000 K. The disc is called the photosphere. The radius of the Sun is almost 100 times the radius of the earth and its mass is about a million times the mass of the Earth.

Planets 

The name planet has been given to all those (bright) heavenly bodies that revolve round the sun. They look like stars but they do not twinkle. We now know that planets do not have any light of their own. Their observed brightness is only due to the light of the sun reflected by them.

There are eight planets in our solar system. They move in elliptical-shaped paths called orbits, around the sun. The eight planets of our solar system, in increasing order of distances from the sun, are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

The planets, relatively 'nearer' to the sun have features that are quite different from those which are 'far-off'. We, therefore, find it convenient to divide the planets into two categories:

1. The Terrestrial planets

2. The Jovian planets

Mercury, Venus, Earth and Mars are the Terrestrial planets. They have solid and rocky surfaces.

The Jovian planets are Jupiter, Saturn, Uranus and Neptune. These planets are very large in size and are made up largely of gases.

In the next post we read about planets details.