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05/13/2021 – Ephemeris – The Moon and Mercury will appear near one another tonight

13 May 2021, 04:01 UTC
05/13/2021 – Ephemeris – The Moon and Mercury will appear near one another tonight
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This is Ephemeris for Thursday, May 13th. Today the Sun will be up for 14 hours and 45 minutes, setting at 9:02, and it will rise tomorrow at 6:15. The Moon, 2 days past new, will set at 11:08 this evening.

Tonight starting around 9:30, or half an hour after sunset is a good time to spot the thin crescent two day old Moon and the planet Mercury. The tiny and elusive Mercury will be about 7 moon widths to right of the Moon. With the Moon near Mercury, it should be easier to find instead of trying to locate it in the great expanse of featureless twilit sky. Mercury has a weird rotational period. In my youth astronomers thought that Mercury rotated so that one face would perpetually face the Sun, So it would rotate in the same time it orbits the Sun of 88 days. That’s what happens when the Moon orbits the Earth. However, Mercury rotates in exactly 2/3rds of its orbital time, making its solar day two of its years long or 176 Earth days.

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

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