LUNAR ECLIPSE TOMORROW
Last updated: 13 June, 2011
Mohan Krishna S A 20:14 IST
Tomorrow, Indians will witness a total lunar eclipse. The eclipse will be visible in the region covering South America, Africa, Europe, the Middle East, Asia, Australia, Antarctica and the Atlantic, Indian and South-western Pacific Ocean.
It will be visible from all parts of India. An eclipse of the moon can occur only at full moon and only when the earth is exactly between the sun and the moon. Unlike a total solar eclipse, which is visible only from a restricted zone of totality, a lunar eclipse is seen from the entire nightside of the earth, providing millions of front-row seats for interested observers.
Lunar eclipses usually precede or follow solar eclipses by a fortnight. The eclipse commences at 11:53 am (23h 53m) and ends at 4:33 am (27h 33m). The maximum of the eclipse can be seen at 3:43 am from all parts of India.
Slow progress of the eclipse
No two lunar eclipses are ever the same, and although some dismiss them as of less interest than solar eclipses, particularly total solar eclipses, where the events centered on totality occur rapidly, the progress of a lunar eclipse is slow and stately, making it more fascinating to observe.
Unless a lunar eclipse is very dark, it is usually quite easy to make out the dark maria, contrasting with the brighter, cratered highlands, with the naked eye. At totality, the moon – completely immersed in shadow – normally shows red, orange and yellow colours, often with some gradation. Those parts of the moon closer to the edge of the umbra often appear somewhat brighter and more yellowish than those toward the centre, which are redder.
Sunlight diffusing through the earth’s atmosphere bathes the moon in a dull glow that reduces it to about one ten-thousandth the normal brightness of the full moon. The same principle causes the early-evening sky to remain relatively bright, even though the sun is below the horizon. A total lunar eclipse unfolds as follows: About 20 minutes before the moon is scheduled to enter the shadow zone, the eastern edge of the moon becomes slightly dusky, indicating that the shadow region is nearby.
However, when the edge of the moon actually contacts the shadow, the darkening effect is unmistakable. During a total eclipse, the moon takes about an hour to slip into the shadow. Once it is fully immersed, the total eclipse begins and can last anywhere from a few minutes to one and half hours.
The next total lunar eclipse can be seen on December 10.
