Solar System

The Sun, with its powerful force of attraction, keeps in orbit around itself 8 (or 9) planets, including the Earth, 68 known satellites, countless asteroids, meteors and comets, and a great quantity of dust and gas. Planets are spherical bodies, small and cold. They shine because they reflect the light from the star around which they orbit.
Other heavenly bodies called satellites often orbit around the planets. There is no life on satellites.

Asteroids are minor planets, small and rocky. They orbit aroundd the Sun betwwen Mars and Jupiter, fforming a flattened ring with a diameter of 12 billions of kilometers.


An orbit is a regular, repeating path that one object in space takes around another one. An object in an orbit is called a satellite. A satellite can be natural, like Earth or the moon. Many planets have moons that orbit them.

Shape of Orbits

In their journeys around the Sun, planets follow an elleptic path. Earth's orbit has a shape of slightly flattened circle.

Direction of Rotation

Planets orbit around the sun, whilst at the same time rotates on their own axis. These rotations are mostly anti-clockwise; only the planet Venus rotates clockwise direction.

Inner Planets or Terrestrial Planets : Mercury, Venus, Earth, Mars.

Outer Planets or Jovian Planets : Jupiter Saturn, Uranus, Neptune.

All Planets move in orbits that are very slightly elliptical.

Five Planets : Mercury, Venus, Mars, Jupiter and Saturn are visible to the naked Eyes.


Asteroids are celestial bodies that circle in a broad belt between the orbits of Mars and Jupiter. It is the debris left over from the formation of inner planets. They are also called Planetoids or small planets. They are chunks of rock covered in frozen gases.
Asteroids are too small to retain any atmosphere of their own. Largest Known is Ceres.


Meteors are also known as Shooting Stars. Meteors are often seen in sky, shooting with great speed producing a trail of light. Meteors are fragment of rock coming towards the Earth, formed due to the colision of asteroids with one another.
Largest known was of 70 tonnes which landed in Namibia in prehistoric times.

What How Why

What is an electric current?

An electric current is a passage of electrons from one electrified body to another which is less charged. When too many electrons are generated, they can move.