An eclipse update

We are being cheated out of the first total solar eclipse of the millenium. Well, we should not grudge Africa this eclipse. We have been quite lucky in the recent past to have had the umbral shadow of the Moon go across India thrice in a decade’s time.

The path of the June 21^st eclipse goes through a narrow strip in southern Africa. The umbral shadow of the Moon will begin in the south Atlantic, cross southern Africa and Madagascar and end at sunset in the Indian Ocean. A partial eclipse will be seen over a much broader path that includes eastern South America, and a wider corridor in Africa than shown in the figure below.

The umbral phase of the eclipse will start at 10 hrs 35 m in the South Atlantic. The total phase in these regions will be about 2 minutes 6 seconds. A little before the shadow moves into Africa, the region of the maximum eclipse is reached at 12.03 GMT, 1100 kilometers west of Africa’s coastline – the eclipse duration here will be 4 minutes 56 seconds.  Eastwards, passing through Angola, Zambia, Zimbabwe and Mozambique, the eclipse duration shortens again. By the time it reaches Madagascar, in the evening of the local time here, the eclipse duration will fall to 2 minutes 25 seconds. Over the course of 2 hours and 54 minutes, the umbral shadow of the Moon travels along a path of nearly 12,000 kilometers long.

A solar eclipse at any point on Earth is usually accompanied by a Lunar eclipse visible over a wider region on Earth, either at the preceding or the succeeding new moon day. That’s what is happening here and on the 5^th of July, a partial lunar eclipse will be visible from India. The geographical regions where the Lunar eclipse will be visible are shown in the map below. Also shown is the exact geometry in which the shadow of the Earth is partially falling on the Moon at this time.

The local eclipse circumstances will be the following –

Moon rise: 7:19  PM on 5/7/2001

Moon set:   4:59 AM 6/7/2001

Magnitude of eclipse :  0.49 (fraction of the Lunar Limb eclipsed)

Partial phase of the eclipse begins:    7:10 PM

Time of maximum eclipse: 8:28 PM

Partial phase of the eclipse ends:      9:47 PM

Well, we will miss the Solar eclipse of June 21^st and the visibility of the 5^th July Lunar eclipse is somewhat doubtful what with the monsoons and the fact that the eclipse is set for Moon rise for India, which will place the Moon plumb at the horizon at the time of the eclipse. Last year, the total Lunar eclipse of 16^th July was a total washout for the same reason, while the midnight Lunar eclipse of January this year was seen so clearly. Our Lunar eclipse viewing prospects are not good till the year 2004 when another late night eclipse may be seen overhead on the 5^th of May. The next total solar eclipse that will be visible from India will be on morning of 22^nd July, 2009. Here is a map of the regions where that will be visible.

A total Solar eclipse being the most spectacular event that one may possibly witness in one’s lifetime, maybe one may not wish to wait till 2009 to see it in northern India, but, rather join in a eclipse safari to Africa!

(The eclipse information has been compiled from the NASA eclipse bulletins issued by Fred Espenak and Jay Anderson)

                written by -   N. Rathnasree,  Director, Nehru Planetarium, Teen Murti House, New Delhi –110011.