MUMBAI, August 10: At 15.00.57 hrs IST precisely, the moon will kill the sun and strike Earth with its awesome shadow first South of Nova Scotia in Canada sweeping the North Atlantic till it reaches the first major landfall on the Isles of Sicily. As the denizens of the Earth look upwards and see the sun die, they themselves will be in the thrall of `death', and, as Virginia Woolf watching a similar phenomenon 52 years ago put it, in amazement `recover' as it were.However, the last celestial spectacle of the millennium may bring little cheer to the less fortunate astronomy enthusiasts, who could not pack their bags to go to Iran or Cornwall in England to view the phenomenon in all its majesty. For one, India is the last nation in the shadow's path. For another, the shadow enters India with the Sun's altitude at just 7 degrees and races across the subcontinent in just about 6 minutes prior to sunset at 18.06.23 hrs when it disappears into space from the Bay of Bengal. The velocity of the umbra as it entersIndia at 2 km per second increases to nearly 3.5 km per second as it disappears from the Bay of Bengal.
To cap it all, is the monsoon weather and meteorologists estimate there is just 5 per cent chance of clear skies. Also the eclipse duration dips sharply. When the shadow enters the West Coast the duration of the eclipse is 1 minute 1 second. by the time it crosses the Indian landfall it has decreased further to just about 20 seconds. The last place on land to witness totality in India will be Srikakulam in Andhra Pradesh with a duration of just 25 seconds.
Though not exactly under the centreline of the umbra, Jalgaon and Amravati in the state will have fleeting glimpse of totality, ie, if the skies are not already dark owing to monsoon clouds. While Ahmedabad is just out of the umbral region, Vadodara ought to experience noticeable totality given fair weather. In contrast, Karachi in Pakistan will experience 1 minute and 13 seconds of total eclipse. Sadly, for Mumbaikars, the chances of witnessing evena partial eclipse look very much dim.
At the other end, Calcutta will witness a partial eclipse of 0.879 in magnitude with the Sun just 2 degrees above the horizon.
According to statistics put out by NASA, the instant of the greatest eclipse, ie. when the distance between Moon's shadow axis and Earth's geocentre reaches the minimum, will be experienced by Romanians. At that point the epicentre of the shadow is located among the ``rolling hills of south-central Romania.'' Here the length of the totality reaches the maximum duration of 2 minutes 23 seconds.
In Cornwall Peninsula, where it is a festive season with every conceivable gimmick being employed to cash in on the event, the maximum duration is enjoyed by Plymouth, that of 1 minute 39 seconds, but London will only witness partiality of 0.968 magnitude.
However, in areas of distinct totality the spectacle will be awesome as the day disappears and the sky is filled with planets, stars, comets and meteors - only to vanish as the shadow races away -like a conjuror's trick, willing unto sight the very universe as it were in the `dark' of the day. Lasting for three hours and seven minutes, the moon's umbra would have travelled along a path of approximately 14,000 kilometres covering 0.2 per cent of the earth's surface at speeds ranging from about 0.65 ks per second to 3.5 kms per second, bringing to a close the last celestial spectacle ever of the century.
Do's and Dont's
Should the skies be bright today and the sun out, be careful not to view the eclipse with the naked eye. The only time it is safe to view is when the eclipse is total; totality in the area of its path will last on an average for just about 24 seconds. The safest way to view the eclipse is by projecting it through a pin-hole on a screen.
Binoculars or a small telescope may also be used to project the image so long as you avoid the temptation of viewing the eclipse directly through them. Special filters designed for the purpose can also be used. Welder's goggles, widelyavailable, with a number of 14 or above, are safe. Exposed film, whether B&W or coloured is NOT safe.
Exposed B&W film containing silver emulsion is. Colour films do not have silver emulsion, nor do all B&W films. Similarly, medical X-ray films with images on them, smoked glass, photographic neutral density filters are definitely not safe. Professionally designed solar filters are however safe.
Copyright © 1999 Indian Express Newspapers (Bombay) Ltd.