Category: Geography
NATURAL SATELLITES
Post Views: 279 NATURAL SATELLITES Any natural heavenly body that orbits around a planet e.g. moon for earth, tritan…
COMPOSITION OF THE SOLAR SYSTEM
Post Views: 390 COMPOSITION OF THE SOLAR SYSTEM The Sun It’s the centre of the universe. Characteristics It’s a star….
THE EARTH AND THE SOLAR SYSTEM
Solar system is the group of heavenly bodies comprising the sun and the nine planets.
The origin of the Solar System
Theories
A theory is a set of reasoned ideas intended to explain facts or events
Passing Star Theory
A star with a greater gravitational pull passed near the sun
It attracted large quantities of gaseous materials from the sun
The materials split, cooled and condensed to form planets
The planets were set in orbit by the passing star
Weaknesses
Doesn’t explain the origin of the sun and star.
Minimal chance of a star approaching another
Materials would disperse than condense
Collision Theory
Star with greater gravitational pull passed near the sun
It attracted large quantities of gaseous materials
The materials split into portions
Large portions collided with smaller ones and swept them to form planets.
The weaknesses are the same as the passing star’s Theory.
Nebula Clod Theory
There was a slowly rotating cloud of dust and gas called Nebula
It cooled and began to contact
Rotation speed increased and successive rings of gaseous materials were formed.
The rings condensed to form planets
The central gaseous material remained as the sun
Evidence
Rotation and revolution of planets in anticlockwise direction Weakness
The origin of nebular is not explained.
Supernova/explosion Theory
There was a violent explosion of a star.
A cloud of dust (nebular) remained from the star.
There was fast movement of the cloud due to the force of explosion.
Rotation speed increased due to gravitational attraction
The cloud flattened into a disc.
The matter began to accumulate towards the centre to form a proto-sun which later began to shine.
The rest of the cloud collapsed to form planets.
Weaknesses
Doesn’t explain the origin of the star
• Doesn’t explain the cause of explosion
IMPORTANCE OF STUDYING GEOGRAPHY
Post Views: 370 IMPORTANCE OF STUDYING GEOGRAPHY Facilitates good relationship among nations by studying geography of other regions of the…
INTRODUCTION TO GEOGRAPHY
Post Views: 501 INTRODUCTION TO GEOGRAPHY The meaning of Geography Scientific study of the earth as a home of man….