Wednesday, July 22, 2009

Solar eclipse of the century

The celestial spectacle on Wednesday, 22 July 2009, will darken major cities, densely populated countryside, and a vast expanse of tropical ocean. The eclipse itself will be a monster, with totality – when the sun is completely covered by the moon – lasting more than 6.6 minutes at maximum. That makes this the longest totality until 2132.

A total solar eclipse occurs once every year or two on average, but each is visible only from a narrow track covering less than 1 per cent of Earth's surface. The eclipse of 1 August 2008, was visible only from parts of the Arctic, Siberia, and central Asia.

The main reason why this year's totality lasts so long is because the eclipse starts just a few hours after the moon reaches perigee, the point at which it is closest to Earth in its orbit . At such a close distance, the moon appears fully 8 per cent larger than the sun and casts a broader than usual shadow. At the point of greatest eclipse in the western Pacific, the path of totality is 258 km wide.

Gravity anomaly:

The Chinese researchers are poised to conduct an audacious once-in-a-century experiment, covering remote observatories on the Tibetan plateau to a cave in a Shanghai suburb. The plan is to test a controversial theory: the possibility that gravity drops slightly during a total eclipse.

NASA's eclipse website
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Independent Professional: Experienced educator and management consultant for engineering educational institutions, researcher, trainer, technical consultant on sustainable technologies, related to cement manufacturing and characterisation, using industrial and agricultural wastes in cement and concrete, durability of concrete and fuel cell power.