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Penumbral Lunar Eclipse - 10th Jan 2020 - the viewing

With the very first full moon of the year 2020, we were lucky to have a partial lunar eclipse. However, if you were a casual observer who sat up late to watch the eclipse, your response to this probably would have been "disappointing".

Partial Lunar Eclipse at maximum - 10th January 2020
Canon 550D, 70-300mm at 300. F5.6 1/1000 ISO200

Penumbral lunar eclipses are usually a bit difficult observe as the contrast isn't that great. Unlike in solar eclipses where what we see is the silhouette of the Moon, in a lunar eclipse what we see is our own shadow. In fact, it is not the shadow itself, but the lighter shadow on the outside.


Earth's umbra, penumbra and the Moon


When the Moon is in the umbra, or the full shadow of the Earth, we get total lunar eclipses. When the Moon is in the penumbra, we get penumbral lunar eclipses. But these can be subdivided too; if only a part of the Moon is going through the umbra, then it becomes a partial lunar eclipse.

Similarly it is possible that only a part of the Moon goes through the penumbra and the rest of it stays out of the shadow completely - this is what happened on the 10th January 2020 eclipse. About 11% of the Moon was still completely out of Earth's shadow. However these are not called partial penumbral eclipses - they are simply called penumbral lunar eclipses. On the other hand, cases where the Moon is completely in the penumbra but not in the umbra, are called total penumbral lunar eclipses.

So how did my lunar eclipse viewing go? It went quite ok. But like I mentioned earlier in the article, it is very difficult to see the eclipse happening with your naked eyes. I managed to take some photographs, but the initial cut shows that they too are a little bit too bright. Playing a little bit with the brightness and contrast I managed to get some ok-ish shots. So here's a montage:


Montage of shots roughly 15 mins apart. All shot with the same settings.

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