- The Moon is about ¼ the size of its mother planet, the earth.
- ‘Antipodes’ are the places diametrically opposite on earth’s surface.
- The incoming short-wave solar radiation is balanced by an equal amount of long wave radiation from Earth going back to space. This is known as ‘Heat balance of earth’.
- The largest amount of reflection of the solar radiant energy which is reflected back into space before reaching the earth’s surface is due to ‘Clouds’.
- The approximate surface temperature on the sunlit side of the earth is 17 .
- Japan is called the ‘Land of the rising sun’ because: Japan, being the eastern most country in the world, it has the earliest sunrise.
- ‘Lunar Sea’ refers to a dark plain on the moon.
- The constellation of stars appears at different positions in the sky at different times during night mainly because earth rotates about its axis.
- The same side of the moon always faces the earth because the period of rotation of the moon on its axis and period of revolution around the earth is almost the same.
- The earth is tiny in comparison with the rest of the universe. It could fit into the sun 3 million times.