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Ephemeris: 07/27/2023 – See the Moon’s Bay of Rainbows at sunrise

July 27, 2023 Comments off

This is Bob Moler with Ephemeris for Thursday, July 27th. Today the Sun will be up for 14 hours and 51 minutes, setting at 9:14, and it will rise tomorrow at 6:24. The Moon, 2 days past first quarter, will set at 1:38 tomorrow morning.

The moon tonight is a waxing gibbous phase, so it’s more than half illuminated by the Sun. The line between light and dark on the left side of the Moon is called the terminator, which before full is the sunrise line. It is where we can see the greatest detail because the Sun is low in the Moon’s sky there, and creates the longest shadows. Compare it to the right side of the Moon which is seen at nearly solar noon where no shadows are seen, so it has a very bland appearance. One of the cool features of the gibbous moon tonight is Sinus Iridium, the Bay of Rainbows, which is on the upper left part of the terminator. Part of the mountain range that partially rings it is seen in sunlight, while that floor of the bay is still in shadow.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.

Addendum

The Moon, with labels for select features, as it might appear at 10 pm tonight, July 27, 2023. Be sure to check out Sinus Iridium (Bay of Rainbows), partially ringed by the Jura Mountains (Montes Jura), catching the rising Sun. Created using Stellarium, LibreOffice Draw, and GIMP.
Categories: Ephemeris Program, Observing, The Moon Tags: ,