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05/25/2021 – Ephemeris – Viewing the lunar eclipse tomorrow morning

May 25, 2021 1 comment

This post is for the appearance of the May 26th lunar eclipse in Michigan.

This is Ephemeris for Tuesday, May 25th. Today the Sun will be up for 15 hours and 10 minutes, setting at 9:15, and it will rise tomorrow at 6:04. The Moon, 1 day before full, will set at 6:09 tomorrow morning.

If we are really lucky tomorrow morning, and it is clear all the way down to the southwestern horizon at dawn we will witness the start of an eclipse of the Moon near sunrise and moonset. The eclipse starts at 4:48 am, but nothing unusual will be visible as the Moon starts to enter Earth’s outer, penumbral shadow. Perhaps by 5:15 the left edge of the Moon might appear dimmer than the right side. The Moon will be getting deeper in that shadow for the next half hour until at 5:45 it begins to enter the Earth’s inner shadow, the umbra. The only light in the umbra is that bent into it by the simultaneous sunrises and sunsets around the Earth. For the next 20 to 25 minutes the shadow will increase until the Sun rises and shortly after that the Moon sets around 6:09.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Moon deep in the penumbra

Simulated image of the Moon deep in the penumbra of the lunar eclipse of May 26, 2021 at 5:40 am. Notice that the left side of the Moon is darker than the right side. I find that the effect is more noticeable when wearing sunglasses to cut down the Moon’s bright glare. Created using Stellarium.

The partially eclipsed moon at moonset

Simulated view of the partially eclipsed Moon of May 26, 2021 setting on a flat horizon. Created using Stellarium and touched up by using GIMP.

Time Event
4:47 am Nautical twilight starts
4:48 am The Moon enters penumbra (Nothing to see, the dimming on the left side is imperceptible)
5:15 am The penumbral shadow should become visible at the left edge of the Moon by this time
5:45 am The Moon enters the umbra (The partial part of the eclipse begins)
6:04 am Sunrise for Traverse City
6:09 am Moon sets for Traverse City

The sunrise and moon set times may vary by more than a few minutes depending on your location.