Sunday, December 11, 2011

The Khusoof or Lunar Eclipse


The khusoof or  Lunar Eclipse will be taking place in Jammu and Kashmir and other parts of the country  between 6:16 pm to 9:48 pm on Saturday, December 10.I am fascinated by moon since my childhood. When I was a youngster my father brought a popular science book in Urdu ‘Nau Saiyare Ektis Chand’ for me. Through this book I came to know that moon is a non luminous body and it shines by reflecting the solar light. I was so upset by this fact that I hid the book lest others may know about the truth that moon does not have its own light. I was naïve like any other child of my age.
 A lunar eclipse occurs when the Moon passes behind the Earth so that the Earth blocks the Sun's rays from striking the Moon. This can occur only when the Sun, Earth, and Moon are aligned exactly, or very closely so, with the Earth in the middle. Hence, a lunar eclipse can only occur during the night of a full moon. It might be expected that during every full moon t the Earth's shadow will fall on the Moon, causing a lunar eclipse.  Lunar eclipses are not observed every month because the plane of the Moon's orbit around the Earth is tilted by about five degrees with respect to the plane of Earth's orbit around the Sun. Thus, when a full moons occurs, the Moon usually lies to the north or south of a direct line through the Earth and Sun. Although a lunar eclipse can only occur when the Moon is  full, it must also be positioned very near the intersection of Earth's orbit plane about the Sun and the Moon's orbit plane about the Earth that is, at one of its nodes.
The shadow of the Earth can be divided into two distinctive parts: the umbra and penumbra. Within the umbra, there is no direct solar radiation. Due to the Sun’s large angular size, solar light is only partially blocked in the outer portion of the Earth’s shadow or penumbra. A penumbral eclipse occurs when the Moon passes through the Earth’s penumbra. A partial lunar eclipse occurs when only a portion of the Moon enters the umbra. When the Moon travels completely into the Earth’s umbra, one observes a total lunar eclipse.
Unlike a solar eclipse, which can only be viewed from a certain relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of the Earth. A lunar eclipse lasts for a few hours, whereas a total solar eclipse lasts for only a few minutes at any given place, due to the smaller size of the moon's shadow.
Since moon is a non luminous body, lunar eclipses (unlike Solar Eclipses) are completely safe to observe with the naked eye - no special equipment or filters are needed. Sometimes a Total Lunar Eclipse is best viewed without any optical aid, and just lying under the stars watching the change as the Moon first gets slightly darker (penumbral phase), then starts to get eaten away (partial phase), finally turning deep red as it enters totality. The eclipse is a unique opportunity to admire and celebrate the beauty and inspiration of this celestial experience. It is also preferable to offer two rak’aat Salate Khusoof.
The Year 2012 sky stores five celestial events for the sky gazers. This includes Annular Solar Eclipse on 20th May, Partial Lunar Eclipse on 4th June, Transit of Venus on 6th June, Total Solar Eclipse on 13th November and Penumbral Lunar Eclipse on 28th November.



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