According to a report in National Geographic News, when it starts, this year's full eclipse will be visible from a narrow arc spanning the Northern Hemisphere. The eclipse will start around 8:30 a.m. Greenwich mean time in the eastern part of the arc, leading to totality in just under an hour. In a much wider swath of the globe-including northeastern North America along with most of Europe and Asia-people will be able to see a partial eclipse.A partial solar eclipse will be visible in India on the afternoon of August 1 with the people in the north-eastern region in a better position to see a substantial part of the sun's disc being obscured by the moon.
The partial eclipse will be seen in the north-eastern region, starting from about 4.08 pm, while in Kolkata, the solar phenomenon will begin at 4.18 pm and end at 6.02 pm, M P Birla Planetarium Director D P Duari said here on Monday.
The greatest and the end phases of the partial eclipse will be visible from most parts of the country, except in Nagaland and Mizoram where the eclipse ends after sunset, Duari said.
The maximum obscuration of the sun will occur at Sibsagar where the magnitude of the partial eclipse will be around 0.8.
The sun will be completely obscured for just under two and a half minutes, "a tad on the short side," according to astrophysicist Fred Espenak, an eclipse expert based at the NASA Goddard Space Flight Center.
A typical eclipse lasts for three minutes, and the longest possible is seven and a half minutes, said Espenak.
The moon crosses between Earth and the sun once a month during the new moon. For an eclipse to happen, the moon has to come directly between the two bodies-it can't be too high or low relative to Earth.
Sometimes the moon will be close enough that just an edge will pass in between, resulting in a partial eclipse.
"About 25 percent of eclipses are total eclipses, and there are about seven of these a decade," Espenak said.
But at any given geographic location, a total eclipse will be visible an average of once in 375 years.
The last solar eclipse visible from the United States was in 1979, and it was seen mostly in the Pacific Northwest.
According to Espenak, for the growing population of skygazers who would love to see an eclipse and can't make it northward this year, it might be best to make reservations to visit southern Illinois.
Weather permitting, people there will get to see total solar eclipses in 2017 and 2024.