Saturday 11 January 2020

Was there an eclipse?


Left image taken at 10.24pm on 10 Jan 2020; right image taken at 2.42am on 11 Jan 2020

Was there a lunar eclipse this morning? Yes, you bet there was. But I had been forewarned that it wouldn't be anything spectacular. The average man-in-the-street, if he were still awake at three o'clock in the morning, wouldn't even be aware that a penumbral lunar eclipse was occurring overhead.

Two weeks ago when an annular solar eclipse had excited much of the country, I had already learnt that there would be an accompanying lunar eclipse happening too. In fact, solar eclipses and lunar eclipses generally occur within two weeks of each other because of the peculiar alignment of the sun, earth and moon in the sky.

So I had been aware of this lunar eclipse all the time. The only problem was that it would be a penumbral lunar eclipse, meaning that the moon would not be moving into the umbra or deepest depth of the earth's shadow. No, the moon would only skim into the penumbra and out again, the whole process taking about four hours to complete.

And because it would be a penumbral lunar eclipse, many people would not even be aware that it was happening. Heck, visibly the moon may not even be a tiny shade darker. The only way to find out the practical truth about this was to look at the moon at its maximum eclipse, which was what I did.

A screenshot of a simulation of the penumbral lunar eclipse 
by timeanddate.com
Maximum eclipse was at 3.10am but at 2.40am, I had already ventured out of the house. Clear night for the moment, moon was high up in the sky, So I took several pictures of it before the clouds came rolling in. About four hours earlier, I had taken similar photographs of the moon for comparison.

In this composite image where I had placed the two moon images side-by-side for comparison (see above), the only discernable difference to my eyes was a tiny hint of shadow in the right-side image. This was the side of the moon closest to the earth's umbral shadow. Other than that, the rest of the moon was totally brightly lit up.

As I mentioned earlier, I had been forewarned that this eclipse would be nothing to shout about. But I had to find out by myself. Having done that, I can only say that I'm now satisfied. Back to bed!



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