Bob Moler's Ephemeris Blog

Whoops, I set my Virtual Moon Atlas app to the 20th instead of the 19th.  I’m fixing the transcript for the blog readers, but the original program will go out as is.  Tomorrow’s program will be substantially the same.

Ephemeris for President’s Day, Monday, February 19th. The Sun will rise at 7:36. It’ll be up for 10 hours and 40 minutes, setting at 6:16. The Moon, half way from new to first quarter, will set at 10:23 this evening.

The crescent Moon tomorrow will be revealing a trio of my favorite craters, just south of the partially illuminated Sea of Tranquility. From north to south or top to bottom, near the terminator or sunrise line is Theophilus, which slightly overlaps the crater wall of Cyrillus, than a bit farther south another older crater Catharina. These craters were named by a Jesuit astronomer Giovanni Battista Riccioli in his book New Almagest in 1651. Most of his crater names have stuck. He didn’t believe in the Copernican Sun centered system or the strict Earth centered system of Ptolemy, but the system put forth by Danish astronomer Tycho Brahe where the Moon and Sun circled the Earth, but the other planets circled the Sun.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The crescent Moon on the evening of February 20th, 2018. showing the craters discussed in the test. Created using Virtual Moon Atlas and rotated to approximate its orientation in the sky after sunset.

For anyone east of here who can see the Moon at 19:00 UT, on the 20th should see Theophilus shadow filled with the crater rim and the central peak poking into sunlight.