A galaxy is a huge collection or system of stars, dust, gas and solar systems. The galaxy to which our solar system belongs is the Milky Way galaxy. This galaxy is also known as the Aakash Ganga and is spiral. This galaxy is one of the galaxies formed in the universe through the Big Bang. Every galaxy consists of stars which are self-luminous objects. In other words, the stars can produce their own light which is produced from gasses that burn within them. One example of a star is our Sun.

Comets are objects which revolve around the sun in elongated orbits. Comets are made up of dust and gas which are held together by ice particles. They are visible only when they approach closer to the Sun. When comets are near the sun, the ice particles will change to gas form. The most famous comet is Halley's Comet which appears once in 76 Years.

Meteoroids are rocky celestial bodies. It revolves around the sun and is made up of dust, ice particles, and gases. The objects in space range in size from dust grains to minor asteroids. Meteoroids are also called as shooting stars.

Meteors are formed when the meteoroids enter the earths atmosphere at high speed and burn up forming a fireball. Meteors are smaller pieces of rocky materials. Meteors will be seen as a bright streak of light that flashes for a moment across the sky. Meteors are usually made up of rocks and metals. There are different types of meteors which are classified based on their size and based on their distance from the sun. Meteor are also called as Shooting star.