Washington, Dec 12 : Sky watchers around the world will witness tonight the biggest and brightest full moon of 2008.

According to a report in National Geographic News, although a full moon happens every month, the one that rises today will appear about 30 percent brighter and 14 percent larger than the other full moons seen so far this year.

This will happen because the moon will be much closer than usual. T

It will be at its closest perigee, which is the nearest that it can get to Earth during its egg-shaped orbit around our planet.

At its farthest from Earth, the moon is said to be at apogee.

Perigee and apogee each happen generally once a month, but the moon's wobbly orbit means that its exact distance at each of those events varies over the year.

The moon's phase can also be different during each apogee and perigee.

"Typically, we don't have the full moon phase and perigee coinciding at the same time, so that makes this event particularly special," said Ed Krupp, director of the Griffith Observatory in Los Angeles, California.

What's more, today's event will be the closest lunar perigee since 1993, at 221,560 miles (356,566 kilometers) from Earth.

Because this unusually close perigee is happening during a full moon, it is expected to have an effect on Earth's tides.

"While high tides happen each month when the sun, Earth, and the moon are aligned, there is going to be an enhanced effect, with the moon being the closest it's been in more than a decade," said Ben Burress, staff astronomer at the Chabot Space and Science Center in Oakland, California.

"This would result in extra-large tides in regions that are susceptible to them, like Nova Scotia's Bay of Fundy," he added.

The moon's apparent larger size tonight might be most noticeable as it rises above the horizon at sunset.

That's when an optical illusion usually comes into play that makes the full moon seem larger, set against familiar Earthly objects, than when it's higher in the empty sky.

"This combination of the moon illusion and close perigee gives sky-watchers a chance to see the biggest and fullest moonrise possible," Burress said.

What makes this event particularly special is that everyone around the world can witness it without the need for special equipment, just clear skies.

"If you are charmed by the idea of seeing the biggest and brightest full moon visible in 15 years, be ready to go outside at sunset and watch for the rising moon in the east," said Krupp. (ANI)