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04/27/2020 – Ephemeris – Sunrise at Theophilus
This is Ephemeris for Monday, April 27th. Today the Sun will be up for 14 hours and 5 minutes, setting at 8:43, and it will rise tomorrow at 6:36. The Moon, 3 days before first quarter, will set at 1:26 tomorrow morning.
If my Moon charting software is correct this is the one evening out of the month when the central peak of the crater Theophilus catches the first rays of the rising Sun, while the crater floor is in shadow. It kind of looks like a bulls eye. It can be spotted with binoculars on the inside of the crescent, on the terminator, the sunrise line about half way between the ends of the crescent. Theophilus is 61 miles (101 km) in diameter. A telescope of any size with 30 to 50 power magnification will really bring out the detail. More magnification may be warranted, but if the bigger image becomes fuzzy, back off the power. It may be the diameter of your telescope due to the wave nature of light or the atmosphere you’re looking through that’s causing the problem.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon as it should appear at 10 p.m. tonight April 27, 2020 EDT (2:00 UT the 28th UT) with Theophilus on the terminator. Created with Stellarium.
Theophilus at sunrise with the Sun illuminating the central peak and the far crater wall. Theophilus’ diameter is 61 miles or 101 kilometers in diameter. The crater walls rise 13 ,3000 feet or 4,400 meters above the crater floor, and the central mountain with four peaks rises 4,600 feet or 1,400 meters above the crater floor. Image and information from Virtual Moon Atlas. This image needs to be rotated clockwise about 45 degrees to match the image above.
10/03/2019 -Ephemeris – The Moon tonight
Ephemeris for Thursday, October 3rd. Today the Sun will be up for 11 hours and 37 minutes, setting at 7:20, and it will rise tomorrow at 7:44. The Moon, 2 days before first quarter, will set at 10:46 this evening.
The planet Jupiter will appear below and right of the crescent Moon tonight. This evening one of the striking lunar craters will be seen at the sunrise line or terminator on the Moon. The crater might just be glimpsed in steadily held or tripod mounted binoculars, and definitely in a small telescope. The crater is Theophilus, some 61 miles (101 km) in diameter located south of the Sea of Tranquility. At lunar sunrise the central peak of the crater catches the Sun of the lunar sunrise way before the floor is illuminated showing a point of light within the circular crater rim against the black floor of the crater. That should happen before the Moon sets at quarter to 11 p.m. The central peak extends 650 feet (200 m) above the crater walls.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Crater Theophilus on the Moon’s terminator at10 p.m. October 3, 2019, Created using Virtual Moon Atlas.
03/06/2014 – Ephemeris – Observing the Moon tonight!
Ephemeris for Thursday, March 6th. The sun will rise at 7:11. It’ll be up for 11 hours and 25 minutes, setting at 6:36. The moon, 2 days before first quarter, will set at 12:56 tomorrow morning.
The Moon’s appearance has changed since I last talked about it on Tuesday. The Crescent is wider. The terminator, the sunrise line on the Moon that gives the Moon it’s now crescent phase has uncovered most of the Sea of Tranquility. In fact the sun will have risen at the Apollo 11 landing site by this evening. With a small telescope just beneath the center of the moon and near the terminator is one of my favorite craters Theophilus with its well-defined central peak. It’s kind of middle-aged for craters on the moon from 1 to 3 billion years old. It’s in much better shape than the crater Cyrillus of nearly the same size that it partially overlaps, which is thought to be at least a billion years older and shows it.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon at 9 p.m. March 6, 2014 highlighting the Sea of Tranquility the Apollo 11 landing site (approximate) and the crater Theophilus. Created using Virtual Moon Atlas.
Lunar craters Theophilus and Cyrillus. Credit: NASA/LRO mapped onto Virtual Moon Atlas.
02/04/2014 – Ephemeris – Viewing the crescent moon tonight
Ephemeris for Tuesday, February 4th. The sun will rise at 7:57. It’ll be up for 9 hours and 57 minutes, setting at 5:55. The moon, 2 days before first quarter, will set at 12:05 tomorrow morning.
The Moon is now beginning to dominate the sky. In small telescopes one of my favorite craters is peeking into sunlight at the sunrise line, astronomers call it the terminator. This one is called Theophilus. Tonight it should be a ring of the circular ramparts lit by the sun as the evening progresses, in the center of which is the central peak just catching sunlight. Theophilus is at the edge of the small Sea of Nectar or Mare Nectaris. For those with small telescopes who want to learn more about how to use them the Grand Traverse Astronomical Society will host a Telescope Clinic at Northwestern Michigan College’s Rogers Observatory on Friday starting at 8 p.m. You can bring your telescope. It’s free, but for the star party the College requests a small donation.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Moon highlighting the crater Theophilus at 9 and 11 p.m. on February 4, 2014. Created using Virtual Moon Atlas.
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