Penumbral lunar eclipse visible in RP

MANILA, Philippines -- Filipinos can watch out for a penumbral lunar eclipse next week, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) said yesterday.

“A penumbral eclipse of the Moon will occur on Feb. 9 and it will be visible in the Philippines,” Pagasa said in its monthly astronomical diary.

This is the second of the six eclipse events this year.

Pagasa said the eclipse begins when the Moon enters penumbra at 8:36 p.m. and ends the following morning at 12:39 a.m.

The astronomical event will also be observed in Alaska, Australia, eastern Asia, Hawaii, New Zealand and the western parts of Canada and the United States.

A penumbra refers to a partially shaded outer region of a shadow that an object casts. A penumbral eclipse occurs when the Moon passes through the faint penumbral portion of the Earth’s shadow, Pagasa said.

“The lunar surface is not completely shadowed by the Earth’s umbra (darkest part of a shadow). Instead, observers see only the slightest dimming near the lunar limb closest to the umbra. The eclipse may be undetectable unless at least half of the moon enters the penumbra,” the state weather agency said.

Pagasa said many penumbral eclipses have few observable effects but the Feb. 9 lunar eclipse “will carry the Moon far enough into the light gray shadow to produce a dimming of the northern lunar limb.”

According to the US National Aeronautics and Space Administration, this event is the deepest penumbral eclipse in 2009, with a penumbral magnitude of 0.899.

“It will be visible to the naked eye as dusky shading in the northern half of the Moon,” Pagasa said.

Last Jan. 26, an annular solar eclipse – the first of the six eclipse events this year – was observed in the country.

In an annular eclipse, the Moon does not completely cover the Sun’s face, as it does in a total eclipse.

A solar eclipse occurs when the Moon’s shadow crosses the Earth’s surface.

Filipino astronomy enthusiasts can also look forward to several celestial events this year – other penumbral lunar eclipses will happen on July 7 and Aug. 6; a total solar eclipse on July 22 and a partial lunar eclipse on Dec. 31.