KATHMANDU: The first full day of summer brings with it one of nature’s great sky shows — an annular solar eclipse.

On June 21, the new moon orbits between the Earth and the Sun passing squarely across the face of the sun along a narrow path running through central and northeast Africa, Pakistan, northern India, Nepal, and southern China.

It does not completely block the sun but will leave a “ring of fire” from the sun when it peaks.

The entire disk of the sun will be covered by the moon. The end result: A beautiful spectacle where a beautiful halo of pearly white light suddenly flashes into the view.

In this situation, semidarkness settles over the landscape. A few of brighter stars and planets can appear. Then a few seconds or minutes later, totality ends. The great show is over.

But the annular eclipse on June 21 falls short of providing such a celestial pageant. Reason: The moon becomes a little too far from the Earth to cover the disk of the sun completely.

The dark conical shadow of the moon, which is called the umbra, extends for some 235,600 miles out into space.

However, on this day, the moon’s distance from Earth will be 237,100 miles.

Therefore, the moon’s dark umbral shadow falls 1,500 miles short of reaching the Earth’s surface.

The ground track of the anti-umbra will make a “path of annularity”, which will average about 33 miles in width, surrounded by a ring of bright sunlight.

This ring will be very narrow and the moon’s apparent diameter will be 99.4%. The width of the ring of sunlight — at its thinnest — will measure not more than Sun’s six-tenths of one percent.

Therefore, the bright ring of the sun’s disk will be uneclipsed. The word annular is derived from Latin word annulus, meaning “ring shaped”.

In recent years, media have branded such events as ‘Ring of Fire’ eclipses.

(With inputs from Agencies)