The Earth’s Revolution SS1 Geography Lesson Note

The word “Revolution” refers to the movement of one body around the sun, the moon revolves around the earth while the earth revolves around the sun.

The moon revolves around the Earth once a month. The earth and moon travel together making a complete trip around the sun once a year. Eclipses occur when the three bodies, the sun, the earth and the moon are in a straight line.

When the moon comes in between the earth and the sun, an eclipse of the sun occurs (solar eclipse). When the earth is in between the sun and the moon, an eclipse of the moon occurs (lunar eclipse).

Revolution is the movement of the earth in its orbit around the sun once in approximately  365 1/4 days i.e. one year. Every fourth year has 366 days and this is called a leap year. All other years have 365 days.

EFFECTS OF EARTH REVOLUTION

1. It determines a year:  The time it takes a planet to complete one revolution around the sun determines one year on that planet. One year on earth is 365 ¼  days. 
2. Revolution determines the seasons. There are two main seasons in the tropical belt. These seasons are the rainy and dry seasons, while in the temperate belt, there are four distinct seasons: summer, autumn, winter and spring.
3. Changes in the altitude of the mid-day sun: This refers to Equinox and Solstices.
4. Varying length of day and night at different times of the year: The length of day and night varies depending on the position of the earth around the sun.
5. Changes in seasonal temperature: It is observed that summers are usually warm and bright while winters are cold and dark in the Arctic region.                   

6. Dawn and Twilight: Dawn refers to the brief period between sunrise and full daylight while twilight refers to the brief period between sunset and complete darkness.

ASSIGNMENT 

1. Explain the earth’s revolution.
2. State four effects of the Earth Revolution.