The Phases of Moon
We have a special relation with Sun and Moon. While Sun is a symbol of energy and power, Moon represents calm and romance. Interestingly, while Sun always rises in the East and sets in the West, Moon doesn’t necessarily follow the same path. Further, there can be significant difference in moon rise and moon set timings from one day to the other. The basic reason for this is that like Earth rotates on its axis and revolves around the Sun, Moon also rotates on its axis and revolves around the Earth.
Due to the rotation-revolution combination, amount of sunlight falling on the Moon’s surface also differs daily. Hence, from New Moon to Full Moon an increasing amount of sunlit surface of the Moon is visible from Earth resulting in different phases of the Moon. Each phase is a fascinating spectacle that has always inspired mankind in its scientific and artistic work. A couple of days after New Moon, when sunlight directly falls on the Moon’s surface that is facing the Sun then a crescent is formed. However, sunlight also reflects off Earth, falls on Moon and slightly brightens up its remaining surface. This amazing view is called as the ‘Earth Shine’.
From Earth we can see only about 50-60% of the Moon’s surface which is known as the Near side and the rest remains hidden as the Dark Side. This is because Earth and Moon are in a ‘Tidal Lock’. It implies that Rotation time of Moon on its axis equals Revolution time of Moon around Earth. Hence, the Dark side remains invisible to us unless someone is lucky to be on a Lunar Mission to explore it.
Moon’s surface has been ravaged by molten lava from volcanic eruptions billions of years back. This caused dark patches called as Maria or Seas (dried) to appear on Moon. Also, since it has no atmosphere, meteors and asteroids collide with Moon resulting in huge craters all over its surface. A telescopic view of the Full Moon clearly reveals these seas and craters. Nevertheless, Moon’s beauty in all the phases doesn’t lose any shine.
Image Gallery: On Day 1, moon is invisible as only 1% of its surface is sunlit