Monday, September 28, 2015

"Super Blood Moon" Provided A Fantastic Sight

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The Super Blood Moon as it appeared to us Sunday night at roughly 8:35 p.m. local time.

It isn't very often that two separate astronomical events occur in conjunction as they did Sunday night. That is,  the coincidence of a maximal area Moon (30 % larger than normal) along with a total lunar eclipse. The maximal area Moon is also called a "super Moon" because of the enhanced diameter and occurs because the Moon is at the point of its orbit called perigee - or the closest point to Earth.

The total lunar eclipse, meanwhile, occurs when the Moon passes completely  through the Earth shadow when Sun, Earth and Moon are in alignment. as depicted below:
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Note the alignment (top) fixes the Sun at one end (left) and the Moon at the other with Earth in between. The light  from the Sun - on intersecting the Earth -  produces a smaller, darker umbra and a lighter outer shadow cone called the penumbra.  If the lunar transit is such that the Moon (as seen from Earth ) only passes through the penumbra, we have a partial lunar eclipse.

If, on the other hand, the Moon passes through the darker umbra, we have a total lunar eclipse and what is called a "blood Moon" because the lunar surface appears reddish or ochre on account of being seen through the Earth's atmosphere. Thus, we observe the Moon as seen in the photo we took.

As may be inferred from the diagrams, on account of the Earth casting a much larger shadow than the Moon (say when there are solar eclipses) the duration of lunar eclipses is longer, including the total phase. An entire lunar eclipse can last for hours as opposed to minutes for the solar eclipse.

Janice and I were fortunate that the weather was terrific and the sky perfectly clear when we went out at about 8:05 p.m. I had my binoculars (7 x 35mm) and Janice used a digital camera mounted on a tripod to take the photo. We took a series of about 8 photos, and decided the one displayed here had the best resolution.

Of course, though the sight may have even inspired fear in some - there were no supernatural associations to be extrapolated. It was a purely natural event that occurs every 2-3 decades. In cade you missed this one, you won't see another until 2033.

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