The Solar System is the gravitationally bound system of the Sun and the objects that
orbit it, either directly or indirectly.
• Our solar system consists of our star, the Sun, and everything bound to it by gravity – the planets
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune; dwarf planets such as Pluto;
dozens of moons; and millions of asteroids, comets, and meteoroids.
• The Solar System formed 4.6 billion years ago from the gravitational collapse of a giant interstellar
molecular cloud.
A star is an astronomical object comprising a luminous spheroid of plasma held
together by its gravity.
• Stars are cosmic energy engines that produce heat, light, ultraviolet rays, x-rays, and other forms
of radiation.
• Stars were formed when the galaxies were formed during the Big Bang.
• They are composed largely of gas and plasma, a superheated state of matter composed of subatomic
particles.
• Stars are the fundamental building blocks of galaxies.
It is a star made up of extremely hot gases, particularly by hydrogen
(70%), Helium (26.5%), and others (3.5%) gases.

• It is 109 times bigger than the earth and weighs 2 × 1027 tonnes, and accounts for 99.83% of the
mass of the solar system.
• It is 150 million km away from ear