09/06/2016 – Ephemeris – The prominent lunar crater Theophilus
Ephemeris for Tuesday, September 6th. The Sun will rise at 7:11. It’ll be up for 12 hours and 57 minutes, setting at 8:09. The Moon, 3 days before first quarter, will set at 10:55 this evening.
The Moon’s terminator, the sunrise line, is half-way across the Sea of Tranquility on our satellite’s equator. Below that is a distinctive crater just coming into light. It’s prominent enough to spot in binoculars. It’s name is Theophilus. The name is familiar with those familiar with the New Testament of the Bible, as the person that the Gospel of Luke and Acts of the Apostles is addressed to. However that isn’t who the crater is named for, but for the Patriarch of Alexandria of the late 4th century. The two other large craters south of Theophilus that will be visible tomorrow are named for two other Orthodox saints of Alexandria. They were named by Giovanni Riccioli a 17th century astronomer and priest, who named many other craters.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
When Theophilus is on the terminator as it is tonight the Sun may touch the crater rim and the central peaks, while the crater floor is still in shadow. It’s a cool sight.
Note that Cyrillus has very low crater walls and is hard to see unless the sun angle is low near lunar sunrise of sunset.