The brightest extraterrestrial object at night, the moon is
the only satellite of the earth. It derives its illumination from reflected
sunlight. As it travels around the earth, the visible amount of sunlit area
changes day by day so that it creates a cycle of lunar phase. From New moon to
full moon there is waxing of the moon’s visible area. And after the full moon
and back to the new moon there is a waning of the moon’s visible area. Craters
on the surface of the moon are the result of massive bombardment of meteors in
the last billion of years.
The moon is an airless, waterless and lifeless earth
satellite. It is about 384,400 kilometers from the earth, and is about a
quarter of its size. It orbits the earth at an average rate of 27.3 earth days
on an average velocity of 1 kilometer per second. A complete rotation of the
moon has also an average of 27.3 earth days. This synchronization of motion is
the reason why only one side of the moon or the near side is turned toward the earth
in many days. The other or far side is always faced away from the earth.
Earth’s gravitational pull affects moon’s orbital and
rotational motions. The moon has only about 16 per cent of the earth’s gravity.
However, the moon causes the level of water in the seas and oceans to rise or
fall. Its gravitational pull is the cause of the phenomena which are called
high tide and low tide.
Man is awed by the brightest spectacle in the night sky
since time immemorial. In reverence to the moon, ancient people considered or
made it their god. There were several moon gods in different places in ancient
cultures. The word lunatic from the Latin “luna” or moon describes a person
whose sanity is affected by a particular phase of the moon.