First partial solar eclipse of 2011 visible on Tuesday

Though not as spectacular as a total eclipse, when the sun is completely obscured by the moon, it is still a rare spectacle to witness the moon take a bite out of the sun.

The visibility of solar eclipse
The penumbral shadow will first touch the surface of the Earth in northern Algeria, at about 6:40 GMT.

As the shadow travels eastwards, Western Europe will enjoy the partial eclipse at sunrise.

The eclipse will be visible in the wee hours of the morning in North Africa and the Middle East, and at sunset in regions of Central Asia, like Mongolia, western China and northwestern India.

Joe Rao, SPACE.com's skywatching columnist, explained, "The first contact of the penumbral shadow (where the sun rises with a barely perceptible nick in its southern edge) coincides with local sunrise a few hundred kilometers northeast of In Salah, an oasis town in central Algeria, at the heart of the Sahara Desert region of northern Africa.”

Best view of eclipse
The best experience of the eclipse is expected to be in northern Sweden, where the moon will hide up to 80 percent of the sun's disk at sunrise.

Observers in Moscow will be treated to sight of 74 percent of the sun blocked by the moon.

People in London and Paris will see the moon obscure about two-thirds of the sun.

"Europeans won't get another opportunity to see the sun covered to this extent until March 20, 2015," reported Sky & Telescope.

The best experience of the partial eclipse is expected to be in northern Sweden, where the moon will hide up to 80 percent of the sun's disk at sunrise.

A little about solar eclipse
A solar eclipse occurs when the moon crosses between the sun and the earth, and fully or partially blocks the sun when seen from a region on earth.

There are at least two solar eclipse in one calendar year which can go up to as many as five. Five eclipses in one calendar year is rare and will not happen until 2206.

Today's eclipse is the first of the four partial solar eclipses in 2011. This phenomenon is also a pretty rare sight in one year.

The last year in which four occurred was 1982, and it will not happen again until 2029.

A word of caution
Although the eclipse is only partial, health regulators are warning people not to look directly at the bright sun as it can damage to the retina of the eye.

This can result in permanent impairment of vision and even blindness. Viewing an eclipse through binoculars, normal sunglasses or a telescope is also extremely hazardous and can cause irreversible eye damage in a fraction of a second.

The safest way to view the eclipse is through cardboard glasses. Experts are urging people to observe the eclipse through specialized glasses or mylar solar filters.

Another safe method to see the eclipse is to reflect the image of the sun onto the side of a building using a mirror.