Rabu, 30 September 2015

Article#470 - Rises And Sets


It may have been quite late to finally comprehend, but as the lunar eclipse tetrad nears its end, I was struck by the fact that I only managed to watch one of them: the second within the tetrad, occuring on 8th October last year. Actually I am supposedly able to watch two: another one occurs within my range of view on 4th April this year, but my circumstamces at that time rendering such observation not feasible. This doesn't even mention the fact that the particular eclipse, the third within the tetrad, comprises a totality duration of roughly five minutes. A duration comparable to that of total solar eclipse (typical total lunar eclipse brings Moon into darkness of Earth's shadow for about an hour), implying that there's no need to invest much time in this regard.

This particular tetrad kicked in with an eclipse on 14th April, providing the spectacle for those in the Western Hemisphere. This proved to be the case again for the last total lunar eclipse, occurred just days ago on 28th September.
It catched my interest, the fact that I would not be able to see the first and the last of the tetrad. My last lunar eclipse before this tetrad was in June 2011, and given the circumstances, I might not be able to watch another one before at least July 2018.

The image of Moon being immersed deep within Earth's shadow is still not a familiar sight to my puny eyes. The dark patches on the surface of the Moon readily gives away a reddish color when compared to its brighter counterpart. We, as students, may have been told over and over that the reddish, copper-like hue is related to sunlight being scattered by Earth's atmosphere, giving away reddish color to the sight of lunar eclipse.
But only after the last, setting eclipse of the tetrad, only I realized that the reddish hue we see on the eclipsed Moon is the same hue we saw during every sunrises and sunsets.
Esentially, total lunar eclipse is Moon being irradiated by sunrises and sunsets.

image source

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