Jupiter and Saturn will appear very close to each other by one-fifth of a full moon but the cloud cover may spoil Filipinos’ chance to spot this rare event Monday.
Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) weather specialist Chris Perez said most of the country will be generally cloudy Monday due to the tail-end of frontal system and northeast monsoon.
A low-pressure area (LPA) also developed Sunday, adding to the possibility that weather may spoil this once-in-a-lifetime astronomical event.
Metro Manila, Perez said, will be cloudy with scattered rain showers and thunderstorms.
The National Aeronautics and Space Administration (NASA) said Jupiter and Saturn have been waltzing their way together all year but they will appear increasingly closer together by around one-fifth of a full moon apart on Dec. 21.
A New York Times report cited that the Jupiter-Saturn alignment is a special one as it will be closest one since 1623.
NASA said that the "greatest" great conjunction between Jupiter and Saturn may not be happening again for the next 60 years, as the two planets will likely appear in a very close distance between each other until 2080.
If weather permits, PAGASA said the giant planets will lie among the background stars of the constellation Sagittarius, the archer, with magnitudes -2.0 and 0.6, respectively.
"To view the atmospheric features of these two planets, satellites and rings will require a modest-sized telescope under a dark and clear sky condition," PAGASA said.
Jupiter and Saturn can been seen about 36 and 34 degrees in the southwestern horizon, it added.
Simultaneous with the Jupiter-Saturn great conjunction this year is the winter solstice.
PAGASA said the Sun will reach the winter solstice on Dec. 21, which means Philippine nights will begin to be longer than daytime.
The winter solstice signals the Earth's completion of another annual circuit around the Sun, it explained.
"This marks the time when the Sun lies at its farthest point south of the equator. It signals the onset of winter in the Northern Hemisphere and summer in the Southern Hemisphere," PAGASA said.