SUN IS THE NEAREST STAR…….. IT IS 150 MILLION KILOMETERS AWAY.
SUN IS A HOT GLOWING BALL OF FIRE………..IT PRODUCE ITS OWN LIGHT ALL THE TIME………………IT IS THE CHIEF SOURCE OF HEAT AND ENERGY OF OUR EARTH
THE HEAVENLY BODIES THAT REVOLVE AROUND THE SUN ARE KNOWN AS PLANETS……………………THERE ARE 8 PLANETS IN OUR SOLAR SYSTEM…….they do not produce their own light….
Each planet move around the sun on its own path called an orbit. The orbit are kind of circular paths with the sun as their centre. The orbits of different planets do not cross each other because planet remains in its own orbit.
The sun and its planets together form the solar system . There are 8 planets in the solar system.
HOW TO LEARN THE SEQUENCE OF PLANETS?
My Very Energetic Mother Just Sent Us Noodles
This shows that :
Planet nearest to sun : mercury
Planet farthest to sun : neptune
Planet nearest to earth : venus and mars
Our earth is at third position from the sun
OUR PLANET IS EARTH
The only planet out of 8 planets where life exist is our earth….
FORMATION OF EARTH
Our Earth did not always look like this. In fact long ago , there was no earth at all. Scientists believe that the earth started as a large ball of burning gases.
This hot cloud of gases spun around for millions of years. As it spun , it slowly became cooler. And as it cooled , it hardened slightly and it surface became cooler.
HARDENING OF UPPER LAYER OF EARTH
Its surface began to wrinkle like a dried plum. The wrinkles became mountain ranges. Water from the rain settled in the low lying places to form oceans , seas , rivers and lakes
Composition (What it is made of)
THE LAYER OF HARD ROCKS COVERS THE EARTH . THIS IS CALLED THE EARTH’S CRUST
5-100 km thick
2 types of crust
Oceanic (very dense, made of basalt)
Continental (less dense, made of granite)
Oceanic and Continental Crust
Very thick layer
Mantle is a mixture of rocks and metals
Made mostly of iron
1/3 of the earth’s mass
It is the centre of the earth……it is very hot………..due to this extreme heat , nothing here can remain in a solid form……….there are metals in molten form.
How are the earth’s layers similar to an egg?
The molten metals and gases lying in the centre of the earth expand due to the great heat and they exert great pressure from inside to force themselves out of the earth’s crust.
The molten material thrown out is called Lava…while the hole in the center of the volcano is called a Crater.