Bob Moler's Ephemeris Blog

September 16:  This is Ephemeris for Thursday, September 16th.* The sun will rise at 7:22. It’ll be up for 12 hours and 28 minutes, setting at 7:51. The moon, 1 day past first quarter, will set at 1:38 tomorrow morning.

We’re looking at the moon this week leading up to International Observe the Moon Night Saturday night. We’ll have some telescopes at the Clinch Park Marina Saturday if it’s clear. The moon tonight is special for those with telescopes. With lots of features that will be revealed by the moon’s sunrise terminator, the sunrise line of the east edge of the visible part of the moon. Starting at the north or top of the moon is the strange square crater Barrow. Below that is the ringed plane, the crater Plato. It’s cool watching the shadows of the crater walls recede as the sun rises. There’s a gash in the mountains nearby called the Alpine Valley. On the southern half of the moon there’s a thin line of a shadow, the straight wall a 900 foot high and 67 mile long cliff.

*Times are for the Grand Traverse Area of Northern Michigan, USA.

Moon 1 day past first quarter. Created using Virtual Moon Atlas.

Is crater Barrow really square?  You be the judge.

Overhead view of the crater Barrow. Created using Virtual Moon Atlas.