Science enthusiasts should mark May 20, 2012 in their calendars as this is the date of a spectacular annular ("ring") eclipse that will be visible from parts of eight western U. S. states and in many other countries all over the world.

But before it, a large partial eclipse will be seen on Friday (Nov. 25) by a small audience when the moon's penumbral or outer shadow will touch the souther part of the Earth. It will touch down in the South Atlantic Ocean and encompass the southern and western portion of South Africa.

The eclipse on Friday will be the fourth time this year that a new moon will orbit between the sun and Earth to cause a solar eclipse.

Compared to the three previous eclipses, the depth of this partial eclipse is greater as 90.5 percent of the sun's diameter will be covered.

As the penumbra slides under the bottom of the Earth, the partial eclipse will be visible in varying extent across Antartica and as it slides back into space it will manage to pass by Tasmania as well as portions of New Zealand's South Island.

Its last contact with Earth will occur west of the South Island in the Tasman Sea.

For the solar eclipse on May 20 next year, astronomers said that for those living in New Mexico and west Texas, they will see the sun transformed into a blazing "ring of fire." However, the sun will appear partially eclipsed for those living in North America.

The annular eclipse will also be visible in some parts of Pacific like China and Japan but this will be seen on the morning of May 21.