08/24/2015 – Ephemeris – The Bay of Rainbows

Ephemeris for Monday, August 24th.  The Sun rises at 6:55.  It’ll be up for 13 hours and 38 minutes, setting at 8:34.   The Moon, 2 days past first quarter, will set at 2:17 tomorrow morning.

One of my favorite lunar formations is creeping into sunlight on the Moon this evening.  Look to the upper left edge of the moon tonight.  The large sea or dark area of the Moon, the Man in the Moon’s right eye as he’s looking at us is Mare Imbrium, the Sea of Showers.  At the top left edge of that sea is a large notch.  And keeping with of seas these of the first telescopic astronomers its name is Sinus Iridium, or Bay of Rainbows, a colorful name for something as colorless as the rest of the Moon.  The terminator which is the sunrise line will be cutting across that bay, illuminating the semicircular mountain ring that surrounds it before all of the floor is illuminated.  It can be seen in binoculars or a small telescope.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Moon at 10 p.m. August 24, 2015 showing the location of Sinus Iridium. Created using Virtual Moon Atlas.

The moon at 10 p.m. August 24, 2015 with Sinus Iridium extending into the lunar night. Created using Virtual Moon Atlas.

This is for 2 hr UT August 25, 2015.