An eclipse of the Sun (or solar eclipse) can only occur at New Moon when the Moon passes between Earth and Sun. If the Moon's shadow falls upon Earth's surface, we see some portion of the Sun's disk covered or 'eclipsed' by the Moon. Since New Moon occurs every 29 1/2 days, you might think that we should have a solar eclipse about once a month. Unfortunately, this doesn't happen because the Moon's orbit around Earth is tilted 5 degrees to Earth's orbit around the Sun. As a result, the Moon's shadow usually misses Earth as it passes above or below our planet at New Moon. At lease twice each year, the geometry lines up just right so that an eclipse of the Sun is seen from some part of Earth.


The Moon's shadow has three parts two of which are nested inside the third. The faint outer shadow is the penumbra. Partial eclipses are visible inside the penumbral shadow. The dark inner shadow is the umbra. Total eclipses are seen in the umbral shadow. The umbra is cone-shaped and narrows to a point. Extending beyond the umbra is the antumbra.

There are four types of solar eclipses:
Partial - Moon's penumbral shadow traverses Earth (umbral and antumbral shadows completely miss Earth)
Annular - Moon's antumbral shadow traverses Earth (Moon is too far from Earth to completely cover the Sun)
Total - Moon's umbral shadow traverses Earth (Moon is close enough to Earth to completely cover the Sun)
Hybrid - Moon's umbral and antumbral shadows traverse Earth (eclipse appears annular and total along different sections of its path). Hybrid eclipses are also known as annular-total eclipses.

The number of solar eclipses in a single year can range from 2 to 5. Nearly 3/4 of the time there are 2 eclipses in a year. On the other hand, it is quite rare to have 5 solar eclipse in a single year. The last time it happened was in 1935 and the next time is 2206.

Solar Eclipse
Introduction
Geographic Region of Eclipse Visibility
2010 Jan 15 Annular 0.919 11m08s Africa, Asia
[Annular: c Africa, India, Malymar, China]
2010 Jul 11 Total 1.058 05m20s s S. America
[Total: s Pacific, Easter Is., Chile, Argentina]