Solar System

The giant family of the sun including planets, asteroids , comets etc is called the solar system.The diameter of the solar system is 10.5 light hour.

Sun:

It is a medium sized star whose surface temperature is about 6000 degree Celsius. Sun revolve around the galactic center once in 2.5 x 108 years. Sun consist of 3 layers which are photosphere, chromosphere, and corona.

Importance of sun in solar system:

1. It is the center of solar system.
2. All the planets revolve around the sun in their own orbit.
3. It provides light to all the planet to shine as they have no light of their own.
4. It provides heat and light energy for the lives of the planets if the life exists there.

Planets:

In solar system, there are eight planets and out of them first four planets which are present inside asteroid belt are called inner planets. They are Mercury, Venus, Earth and Mars. But the remaining four planets are out of the asteroid belt and are called an outer planet. They are Jupiter , Saturn, Uranus, and Neptune.

Some important facts about planet:

1. Nearest planet to sun = Mercury
2. Farthest planet to the sun = Neptune
3. Fastest rotating planet = Mercury
4. Morning and evening star = Venus
5. Hottest planet = Venus
6. Green planet or living planet = Earth
7. Red planet = Mars
8. Largest planet = Jupiter
9. Planet having ring = Saturn
10. Planet that can float in water = Saturn

Satellites

• Natural satellite:

  They are that member of the solar system which revolve around the planets in their elliptical orbits . There are about 163 natural satellites. All the planets do not have satellites. Mercury and Venus have no satellite.Satellite are nonluminous bodies but they appear bright by reflecting the sunlight.The number of satellite are different and are given below:

  1. Mercury = 0
  2. Venus = 0
  3. Earth = 1
  4. Mars = 2 (Phobos and Deimos)
  5. Jupiter = 63 (Europa,Callisto)
  6. Saturn = 60 (Titan)
  7. Uranus = 27 (Miranda, Ariel)
  8. Neptune = 13(Nereid)

• Artificial satellite:

  An artificial satellite is made on the earth which moves continuously around the earth. The orbit of the artificial satellite is elliptical and characterized by the parameters, apogee, perigee, and inclination. Satellites are launched for different purposes.

Asteroid:

The piece of rocks revolving around the sun between variable size and about 200 asteroids are present in the solar system. The diameter of asteroids varies from 100m to 700 km.The largest asteroid is Ceres which takes 4.6 years to revolve around the sun.

Comet:

A comet is a frozen chunk of gas,dust and ice which when approaches the sun it begins to resemble a foggy star with the long shiny tail. They are the block of icy rock materials and surrounded by the large mass of substance like water, ammonia, methane,etc .They make round the sun in highly elongated oval orbit , so they spend most of their time away from the sun.

Meteors and meteorites:

Small pieces of rocks or metals which enter the earth's atmosphere from outer space with very high speed are called Meteors. They are also called the shooting star. If meteors are too big, then it will not burn completely and reach on earth. Some objects which land on the earth from the outer space are called the meteorite.