Paste the picture of increasing and decreasing sizes of moon into your activity book. Find out the reason for this increase and decrease in size and write down in a paragraph.
Answers
When the Earth (and therefore the Moon) is at its perihelion, the closest point in its orbit to the Sun, the sunlight that reflects off the Moon is slightly more intense, causing the full moon's brightness to increase by about 4%, which is imperceptible by the human eye.
A waxing crescent moon is when the Moon looks like crescent and the crescent increases ("waxes") in size from one day to the next.
Astronomically and Technically Speaking, the Moon does neither increase nor decrease.
In fact the MOON undergoes The Two Important Fortnightly Phenomena i.e the Waxing and the Waning Moon that causes the phases of the moon.
Since the Moon is tidally locked with the Rotation of the Earth we always see ONE SIDE of the moon. The rotation and revolution of the MOON are of the same duration and therefore the farside of the moon never comes in front of us.
Many moons in the Solar System are tidally locked with their hosts and they too move in similar manner and have phases like our moon.
Galileo discovered that the moons of Jupiter - Ganymede, Callisto, Io and Amalthea revolve around the planet Jupiter always facing the host with one side only. Their Rotation has been retarded by Tidal Friction. Thanks.