Sun

Sun is the biggest star in the solar system and consists of 99.86% of all the mass of the solar system. It is located in the centre and is a sphere of hot plasma. Continuous nuclear reactions take place in its core which radiates energy in the form of light and infrared radiation. Sun is the most significant and primary source of energy for life on Earth. Its mass comprises approximately 73% of hydrogen, approximately 25% of helium and remaining of oxygen, carbon, neon and iron.

Planets

The solar system consists of eight planets, namely, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Mercury is closest to the sun and also the smallest planet. It has no natural satellites.

Asteroids

Asteroids are big and irregular shaped pieces of carbon, rock or metal which can be found mostly in the asteroid belt, orbiting the Sun between Mars and Jupiter. These are also often called minor planets as they are much smaller in comparison to the planets.

Comets

These are small and irregular shaped objects composed of ice. It is believed that they generally come from the Kuiper belt. Kuiper belt is the outermost region of the solar system beyond Neptune. When comets come close to the Sun, due to the heat the ice vaporizes and leaves a beautiful tail behind them. Halley’s Comet is one of the comets that appear once every 76 years and is also visible with the naked eye.

Satellites

The objects that revolve around the planets in the same direction as that of the planet are known as satellites. These are also a part of the solar system. Moon is Earth’s natural satellite. Satellites can also be man-made known as artificial satellites. Artificial satellites revolve around the Earth much closer than the moon.

Stars

A star is a celestial object that consists of a luminous spheroid of plasma which is bound by its own gravity. During the night, they are easily visible with a naked eye. A star shines because a thermonuclear fusion of hydrogen into helium takes place in its core. These are grouped into constellations and asterisms.

Dwarf Planets

A dwarf planet is an object that is in direct orbit of the sun and has not cleared the neighbourhood around its orbit like a planet but is not a satellite. It can be found in various places. Pluto was earlier a planet but now it has been categorized as a dwarf planet.