05/24/2021 – Ephemeris – Get ready for Wednesday morning’s lunar eclipse

This is Bob Moler with Ephemeris for Monday, May 24th. Today the Sun will be up for 15 hours and 8 minutes, setting at 9:14, and it will rise tomorrow at 6:04. The Moon, 2 days before full, will set at 5:33 tomorrow morning.

If we are really lucky Wednesday 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 as the Sun rises and the Moon sets. The first inkling that something strange is happening to the Moon will come around 5:15 am or so. The Moon will be deep in the Earth’s outer, partial, shadow called the penumbra and the left side of the Moon should appear darker than the rest of it. The brightening of the twilight should enhance the effect. The partial phase of the eclipse will start at 5:45, where the left edge of the Moon will actually begin to disappear into the Earth’s inner shadow, the umbra. Within 20 to 25minutes later the Sun will rise and shortly after the Moon will set.

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

Addendum

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.

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.