The Earth in the Solar System
Masses of natural matter such as stars, galaxies, planets, moons, asteroids, comets, nebulae, etc., located in space, both known and unknown, are called celestial bodies.
Celestial bodies, which have their own heat and light, are called stars. The sun is a star. The sun, eight planets, satellites and some other celestial bodies known as asteroids and meteoroids form the solar system.
There are eight planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune) in our solar system. Our earth is the third nearest planet to the sun. The Moon is only natural satellite of the planet Earth, but Jupiter has 62 know satellites.
Numerous tiny bodies, which move around the sun, are called asteroids. The small pieces of rocks which move around the sun are called meteoroids. Various patterns formed by different groups of stars during the night are called constellations. Small Bear/ Saptarishi is one such constellation.
A large area, particularly of dust, stars and gas that makes up a universe is called galaxy. There are millions of such galaxies that make the Universe. It is difficult to imagine how big the universe is. Scientists are still trying to find out more and more about it. The size of the whole Universe is not known and may be infinite.