Indonesians to Witness Third Installment of Lunr Eclipse Tetrad

Jakarta (Antara) -- Indonesians will get to witness a total lunar eclipse on Saturday, the third in a series of four eclipses, known as a lunar tetrad, which began nearly a year ago. According to the Meteorology, Climatology and Geophysics Agency (BMKG), people all across the Indonesian region will have the chance to see a total lunar eclipse, but it will depend on the weather. While in the western Indonesia region, the eclipse will begin at 3:59 p.m. and end at 10:00 p.m., the total phase of the eclipse will last for 12 minutes from 6:54 p.m. to 7:06 p.m. In astronomy, a tetrad is a set of four total lunar eclipses that occur within a span of two years. An astronomer and narrator at Jakarta\'s Planetarium and Observatory, Cecep Nurwendaya said that Indonesia had experienced the first eclipse of the tetrad on April 15, 2014, and the second on October 8 later that year. Nurwendaya, who was a research assistant at the Bosscha Observatory, pointed out that a lunar tetrad was a rare phenomenon and merely 32 of them will occur during the third millennium. During the third installment, the moon will also bear a reddish color, a phenomenon known as a \"blood moon,\" due to Rayleigh scattering. Rayleigh scattering occurs when particles in a medium scatter light without changing its wavelength. Rayleigh scattering of sunlight in the atmosphere causes diffuse sky radiation, which is what gives the sky its blue color and the sun its yellow tone. \"The higher the degree of pollution in the atmosphere, the more beautiful the color of the moon will be during the eclipse,\" Nurwendaya affirmed. The presence of gasses and dust from air pollution give the moon its red color during the eclipse. Furthermore, the final installment of the lunar tetrad will occur on September 28, 2015. However, the possibility of being able to see the eclipse will depend on the weather. Moreover, Head of the BMKG Kupang Sudaryono noted that the provinces of West Nusa Tenggara and East Nusa Tenggara will possibly be the best locations from where the eclipse can be observed, as the two regions will have a relatively low cloud cover, according to the forecast, which could have prevented the lunar eclipse from being visible. The third installment of the lunar tetrad will also be visible in North America, the Pacific Ocean, Australia, and Asia, except around the western Asian region and some parts of eastern Africa. (*)