Why is a ring formed during an annular eclipse?
When a ‘central’ solar eclipse happens to take place at a moment when the sun is closer than average AND the moon is farther than average, the sun looks bigger than average and the moon looks smaller than average. At that moment, their centers coincide and we would hope for a beautiful total solar eclipse. But the moon is not quite big enough to cover the full disk of the sun, so there is a narrow ring of unobstructed sun sticking out around the edge of the moon. Just to sound wise, astronomers call the ring an “annulus”, and this event is called an “annular” eclipse.
