GEOGRAPHY(VI)- CHAPTER 1 THE EARTH IN THE SOLAR SYSTEM (LESSON NOTES)

GEOGRAPHY(VI)- CHAPTER 1

THE EARTH IN THE SOLAR SYSTEM

(LESSON NOTES)

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v INTRODUCTION

Ø It is fascinating to see the sky at night from early time. There are lot of object in the sky, sun, moon, stars etc. which were remain a mystery for human beings. But they also started to use these objects for themselves. In this lesson we will try to understand about these object of universe.

v CELESTIAL BODIES

Ø The sun, the moon and all those objects shining in the night sky are called celestial bodies.

Ø The Stars and the moon are celestial bodies which are visible at night where sun see in a day.

Ø The moon appears differently on different nights—

§  Full Moon or (Poornima) -only once in a month

§  No moon or New moon (Amavasya)- No moon in the sky.

v STARS

Ø The celestial bodies which are made up of gases and have their own heat and light are called as stars.

Ø Stars are very big and hot. We do not feel the heat and light of the stars other than the sun since they are very far away from us. The sun is also a star.

v CONSTELLATIONS

Ø Various patterns formed by groups of stars are called as constellations. Ursa Major (the Big Bear), The Small Bear (Saptarishi), etc are some well-known constellations.

v POLE STAR

Ø The shining star which indicates the north direction is known as Pole Star. It always remains in the same position in the sky. It was used in the ancient time to know about direction.

v SOLAR SYSTEM

Ø The sun, eight planets, satellites, asteroids and meteoroids form the solar system. Sun is the head of the solar system.

OUR SOLAR SYSTEM

v THE SUN

Ø The sun is in the center of the solar system. It binds all planets.

Ø It is made up of extremely hot gases.

Ø The sun is about 150 million km away from the earth.

v PLANETS

Ø The celestial bodies which do not have their own heat and light and move around the sun are called as planets.

Ø There are eight planets in our solar system. The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

(My Very Efficient Mother Just Served Us Nuts)- To memorize

v ORBITS

Ø The planets move around the sun in a fixed paths which is known as orbits. These paths are elongated. 

§  A new planet 2003 UB313 has been discovered. It is bigger than Pluto and is farthest from the sun.

v EARTH

Ø It is the third nearest planet to the sun and fifth largest planet of our solar system. Its shape is Geoids.

Ø The earth is a unique planet because it supports life. It is neither too hot nor too cold. It has water and air, which are very essential for our survival. The air has life-supporting gases like oxygen.

Ø It is also called the blue planet because its two-thirds surface is covered by water

v SATELLITES

Ø A celestial body which revolves around a planet in a particular orbit is called a satellite. The moon is a satellite of the Earth. There are many artificial satellites also like- Indian satellites in space are INSAT,IRS, EDUSAT, etc.

v THE MOON

Ø It is the only satellite of the earth.

Ø Its diameter is one-quarter of the earth. ‘

Ø It is about 3,84,400 km away from us.

Ø It moves around the earth in about 27 days. It takes exactly the same time to complete one spin. So Only one side of the moon is visible to us from the earth.

Ø No life exists on moon as it has neither water nor air.

v ASTEROIDS

Ø The numerous tiny bodies which move around the sun between the orbits of Mars and Jupiter are called as asteroids. The largest asteroid is the Ceres.

v METEOROIDS

Ø The small pieces of rocks which move around the sun are called meteoroids. When these pieces falls on the earth without being completely burnt, they are called as meteors.

v GALAXY

Ø A collection of innumerable stars are called as galaxy. The Milky Way or Akash Ganga is the galaxy of our solar system.

v UNIVERSE

Ø The collection of galaxies is called us Universe. There is only one Universe and everything that exists in this Universe itself.

v TERMS-

v Geoid: The shape of the earth is called a geoid. A geoid is spherical except for the flattening at two places diametrically opposite to each other.

v Poles: The two places diametrically opposite to each other and which lie on the axis about which a spherical body rotates are called poles.

v Dwarf planets :-Plato (From August 2006), Ceres, 2003, UB313

v Geography-Description about the Earth

v Geology-Study of Earth interior

Smallest planet	Mercury
Largest planet	Jupiter
Red Planet	Mars
Blue planet/Home Planet	Earth
Nearest Planet to the Sun	Mercury
Furthest Planet From Sun	Neptune
Earth Twin	Venus
Planets with Rings	Saturn/Uranus
Mercury Completed one year in	88 days
Speed of Lights	3 Lakh KM per second
First Person Step On moon(world)	Neil Armstrong(USA) 21 July,1969
First Person In Space	Uri Gagrin(USSR)
India First Satellite	Aryabhatt (1975)
IAN	International Astronomical Union
Light of sun reach to Earth	500 seconds(8 Minute 20 second)