Explain the following terms: - a) Universe b) Constellation c) Galaxy d) Satellite

1. a) Universe: -A limitless vacuum is having millions of stars, planets, satellites, asteroids,

Comets etc.

1. b) Constellation: - A group of stars forming various patterns and forms-human, animal etc. is called a constellation.
2. c) Galaxy: A huge system of stars is called Galaxy. It has billions of such stars very close to one another. 
3. d) Satellites: - Satellite is a celestial body that moves around the planets in the same way as the planets move around the sun.