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02/20/2018 – Ephemeris – Tonight’s the night to spot a chain of three of my favorite craters
Ephemeris for Tuesday, February 20th. The Sun will rise at 7:35. It’ll be up for 10 hours and 43 minutes, setting at 6:18. The Moon, 3 days before first quarter, will set at 11:29 this evening.
I was a day off in my Moon calculations yesterday. The three of my favorite craters, just south of the partially illuminated Sea of Tranquility will be visible tonight. From north to south or top to bottom, near the terminator or sunrise line is Theophilus, which slightly overlaps the crater wall of Cyrillus, then a bit farther south another older crater Catharina. These craters were named by a Jesuit astronomer Giovanni Battista Riccioli (Ri’cholli). He even named a crater Copernicus, even though he followed the Church teachings of the time he didn’t believe in the Copernican Sun centered system, 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.
Repeating from yesterday: 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. It should be visible from Europe and the Mid East. Let me know with a comment if I guessed right.
02/19/2018 – Ephemeris – A trio of craters emerge into sunlight on the moon tomorrow night
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.
10/06/2016 Ephemeris – Viewing the Moon tonight
Ephemeris for Thursday, October 6th. The Sun will rise at 7:47. It’ll be up for 11 hours and 25 minutes, setting at 7:13. The Moon, 3 days before first quarter, will set at 10:44 this evening.
Tonight the waxing crescent Moon will appear between Saturn on the right and Mars on the left. In a small telescope the Sea of Tranquility is now mostly in daylight. The Sun will rise on the Apollo 11 landing site about one this afternoon. The landing site cannot be seen from the Earth, it’s artifacts are too small. The Lunar Reconnaissance Orbiter has to get down to about 15 miles altitude to photograph them. The craters of Theophilus, Cyrillus and Catharina are seen to the south of Tranquility. Just south of them there looks like a wrinkle in the Moon surface. It’s the Altai Scarp, which is named for the Altai mountains of central Asia. The three craters border the small Sea of Nectar. The lunar seas are basins of solidified lava.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Moon Chart for tonight (October 6, 2016) at 9 p.m. showing the areas discussed above. Created using Virtual Moon Atlas.’
The Apollo 11 landing site in one photograph by the Lunar Reconnaissance Orbiter. There are many with varying Sun angles in the Internet. Search for: Apollo 11 LRO images. Credit NASA.
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.
Addendum
The Moon at 9 p.m. September 6, 2016 showing the crater Theophilus. Created using the Virtual Moon Atlas.
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.
Three Alexandrian saints, Theophilus, Cyrillus, and Catharina (St Catherine) immortalized on the Moon. Created using the Lunar Reconnaissance Orbiter texture on the Virtual Moon Atlas.
Note that Cyrillus has very low crater walls and is hard to see unless the sun angle is low near lunar sunrise of sunset.
Bob Moler's Ephemeris Blog 