Universe

All the matter, energy, and space that exists is Universe. Galaxies, stars, solar system etc are the main constituent of the universe. The branch of science that deals with the study of Universe is called Astronomy. The study of the origin, evolution and nature of universe is called Cosmology.

The Solar System

The part of the universe in which we live is called solar system. It includes planets , asteroids and comets revolving around the sun. The vaarious members are bound to each other by gravitational force of attraction.

The Sun

Sun is a star which mainly contains extremely hot hydrogen gas. Sun radiates energy in all direction, which reaches all part of solar system. The outer visible region is called photosphere and invisiblepart is called chromosphere. The mean distance between Earth and Sun is 1.496 × 10^11 and is called 1 Astronomical Unit.

I will continue about The planets in next post. Please upvote, comment and reesteem .