2nd blue moon due Tuesday; 3 planets to be visible

Stargazers will have a chance to see the last of this year’s exceptional blue moon phenomenon on Tuesday, the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) said. Aside from the rare phenomenon, stargazers would also have the chance to see Uranus, Neptune and Venus before dawn on the same day. PAGASA head Prisco Nilo said the occurrence of a blue moon - two full moons in one month - on March 1 and 30 is the second since January this year. “The next blue moon will be on August 2 and 31, 2012," Nilo said in PAGASA’s astronomical diary for March. On the average, a blue moon takes place once every two and a half years. Literally blue PAGASA noted that since the moon takes 29.5 days to circle the Earth once in its orbit, it is possible that two full moons can occur within the same calendar month, like what happened last January when the moon was full on the 1st and the 30th, making the full moon on the 30th a “blue moon." Nilo also said there have been times when the moon does seem to have a blue color due to dust particles in the atmosphere that scatter light. The effects of this dust on the light coming from the moon can cause it to appear bluish in color. He cited the eruption of the Krakatoa Volcano in 1883 that gave us one such “blue moon." “For about 24 months after this volcano erupted, the dust it spewed into the upper atmosphere which caused the moon to appear green and blue when viewed from around the world," he said. 3 planets visible Pagasa said Uranus, Jupiter and Neptune may be "visible" at about 5:30 a.m. Tuesday. At that time, it said the three would be at 3, 10 and 30 degrees above the east southeastern horizon and would be glowing at magnitude +8.0, -2.0 and +5.9, respectively. “Jupiter and Neptune will lie among the background stars of the constellation Capricornus, the Sea-Goat while Neptune will be found among the stars of the constellation Pisces, the Fish," it said. PAGASA, however, said that a modest-size telescope would be needed to observe Neptune, the Blue-Green planet, while Uranus would be difficult to observe due to its proximity to the sun. – KBK/RSJ, GMANews.TV