Grade 8 Geography : Solar System - Part 2

The solar system is composed of several celestial bodies like the Sun, the eight planets (Mercury Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune), and the dwarf planets, the natural satellites of planets, rock particle and debris like asteroids, comets and meteoroids. The Sun is a ball of hot, glowing gases like hydrogen, helium, oxygen, carbon, iron and etc. It is also the largest object in the solar system. Just like the earth, the sun also revolves around its own axis and one rotation takes 25.4 earth days.  Life on earth heavily depends on the warmth and the light provided by this star found in the heart of the solar system. Similarly, it provides light and heat energy to all the planets in the solar system. We cannot imagine life on our planet without the existence of the sun. Fusion and thermonuclear reactions that occur within the sun lead to the generation of a huge amount of heat in its core that has a temperature of around 15 million 0C. It should be noted that the temperature of the surface of the sun is around 6000 0C and in the event of a typical solar storm that occurs on its surface, flames may burst out from the sun. A majority of the mass or substances of the solar system is occupied by the sun. Its diameter calculates up to 1.4 million kilometers, which is nine 109 times of that of the earth.

 

 

Planets are celestial bodies that are spherical in shape and they move in orbits around the sun. The Solar System has eight planets as we have already mentioned. It should be noted that a belt of asteroids exist between Mars and Jupiter. The planets that are situated between the sun and the above belt of asteroids are called Inner Planets. The crusts of these planets are composed of minerals like silicates and the cores are made of metals like iron and nickel. Planets like Mercury, Venus, Earth and Mars can be cited as Inner Planets. On the other hand the outer planets are those located out of the asteroid belt and they are made of gases like hydrogen and helium. Jupiter, Saturn, Uranus and Neptune are the outer planets of the solar system. 

 

 

 

 

 

 

 

 

by Mekhala Egodawele

 Photo source : Internet