01/23/2018 – Ephemeris – The Moon tonight: the Sea of Tranquility and a crater named for Julius Caesar

Ephemeris for Tuesday, January 23rd. The Sun will rise at 8:10. It’ll be up for 9 hours and 28 minutes, setting at 5:38. The Moon, 1 day before first quarter, will set at 12:30 tomorrow morning.

Let’s take a look at the Moon tonight with binoculars or a small telescope. The crescent Moon tonight has completely revealed the Sea of Tranquility, or Mare Tranquillitatis. Right on the western edge, east to us, of the sea is a ruined crater called Julius Caesar. It seems to have formed by a small asteroid collision in the first half billion years of the Moon’s existance. It’s shape was distorted by the impact that created the Sea of Tranquility. The Moon’s so-called seas are all pretty much impact craters, just really big ones. North of Tranquility is the Sea of Serenity which will be completely in sunlight tomorrow night. By the way, the Grand Traverse Astronomical Society telescope clinic that was scheduled for January has been moved to February 2nd.

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

Addendum

The fat crescent Moon at 8 p.m. January 23, 2018. Created using Virtual Moon Atlas.

The crater Julius Caesar from photographs supplied with Virtual Moon Atlas.