THE EARTH AS A PLANET

THE SHAPE AND SIZE OF THE EARTH.

SHAPE.

The earth is spherical in shape. It is not flat as people used to believe. The earth has a special shape called geoid. SIZE. The earth is the fifth largest planet in the solar

system. It is approximately 443m km2. Its equatorial circumference is 40,085 km Its equatorial diameter is 12762 km. While the polar circumference and diameters are

39,955km and 12,722km respectively.

THE PROOFS OF EARTHS SPHERICITY.

The facts to prove that the earth is spherical include

Circumnavigation of the earth as proven by Magellan and his crew between 1519 and 1522.

Sunrise and sunset. The sun rises and sets at different places at different times in the world. This is possible only on a spherical earth.

Circular horizon. Horizon widens with increase in altitude. This can only happen on a spherical earth.

OTHER FACTS;

Others are, Ships visibility, ie it is possible to travel round the world and still return to the starting point.

Bedford's level experiment; this is a fact that on a spherical earth, the middle pole projects higher than the other two unlike the straight nature on a flat earth.

Lunar eclipse, the circular picture of the earth cast on the moon reveals earths shape during eclipse.

Shape of other planets; other planets, the sun, moon satellites have spherical shape so the Earth cant be in exception.

Aerial photography, shows the satellite view of the earth as seen from space. which is the most recent and up to date fact to prove that the earth is spherical.

ASSIGNMENT;

On a 20cm by 20cm cardboard, draw the polar and equatorial dimensions of the earth. To be submitted on the first day of resumption.