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Ephemeris: 09/12/2025 – Cassiopeia through the year

September 12, 2025 Comments off

This is Ephemeris for Friday, September 12th. Today the Sun will be up for 12 hours and 39 minutes, setting at 7:58, and it will rise tomorrow at 7:19. The Moon, 2 days before last quarter, will rise at 10:19 this evening.

The constellation of Cassiopeia the queen looks to most of us like the letter W. However, since it is circumpolar, that is it seems to move around the North Pole of the sky without setting. It represents to us with various orientations. When it’s seen now in the evening in the northeast, it kind of looks like a misshapen number 3. In early winter it would be nearly overhead and be the letter M, not the University of Michigan block letter M, but the angular University of Minnesota M. In early spring, it’s in the northwestern sky as the Greek capital letter sigma. And finally in early summer it’ll be low in the north and become the upright letter W. I’ll return to Cassiopeia and tell her story later this autumn.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

The orientation of Cassiopeia, and also the Big and Little Dippers at 3 month intervals.
The orientation of Cassiopeia, and also the Big and Little Dippers at 3 month intervals. It’s the same as 6 hour intervals on the same night. I’m cheating here by keeping the sky dark. Created using Stellarium, LibreOffice Draw, and GIMP.

Categories: Constellations, Ephemeris Program, Observing

Ephemeris: 09/11/2025 – Finding Pegasus the flying horse

September 11, 2025 Comments off

This is Bob Moler with Ephemeris for Thursday, September 11th. Today the Sun will be up for 12 hours and 43 minutes, setting at 8:00, and it will rise tomorrow at 7:18. The Moon, 3 days before last quarter, will rise at 9:43 this evening.

While we’ve been watching the stars and constellations of summer and the Milky Way, the constellations of autumn have been sneaking up on us from the east. Low in the east at 9 PM is one of the greatest constellations of autumn, Pegasus the flying horse. Her body or at least the front part of it is a large square of stars called the Great Square of Pegasus. It is an almost perfect rectangle. However, as she’s rising, it’s standing on one corner. This year it is above and left of Saturn. From the upper star are her front legs, from the rightmost star her neck and head extend in the stars. And from the left star of the square are what might look like her hind legs but aren’t. Only half of her body is in the stars. It’s another constellation, Andromeda.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

The four stars of the Great Square of Pegasus can be seen in the east. This year they're above the planet Saturn.
As autumn approaches. the four stars the Great Square of Pegasus can be seen in the east. This year they’re above the planet Saturn. In mid autumn Pegasus will be high in the south flying upside down, apparently a very aerobatic flying horse. Her story belongs to the great star story of the autumn constellations, of which I’ve given my take on here. Created using Stellarium, LibreOffice Draw, and GIMP.
Categories: Constellations, Ephemeris Program, Observing Tags:

Ephemeris: 09/10/2025 – Our weekly look at the naked-eye planets

September 10, 2025 Comments off

This is Bob Moler with Ephemeris for Wednesday, September 10th. Today the Sun will be up for 12 hours and 46 minutes, setting at 8:02, and it will rise tomorrow at 7:17. The Moon, 3 days past full, will rise at 9:14 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Saturn now rises at 8:30 PM in the east. In a telescope Saturn sports a very thin ring, 2¼° from being edge on. Saturn has an axial tilt of about 27°, so it has seasons like the Earth and since its rings are over its equator, when the go edge on to the Sun, it is an equinox for it, which happened in May. Earth being close to the Sun and moving, see nearly the same thing. Now the ring angle will decrease to about a third of a degree by November 23rd before increasing. By 6 AM Jupiter will appear above the brighter Venus in the eastern sky and among the stars of Gemini. Venus and Jupiter are joining the bright winter stars, a beautiful sight in the morning twilight.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Saturn and the Moon at 10 PM tonight
Saturn and the Moon at 10 PM tonight, September 10, 2025. Created using Stellarium.
The Moon tonight, September 10, 2025. A view visible in small telescopes showing an image with and without selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
Venus and Jupiter are visible in the east among the winter stars at 6:00 AM tomorrow morning
Venus and Jupiter are visible in the east among the winter stars at 6:00 AM tomorrow morning, September 11, 2025. Saturn is off in the west-southwest. Created using Stellarium and GIMP.
Telescopic Saturn, Jupiter and Venus (north up) as they would be seen in a small telescope with the same magnification
Telescopic Saturn, Jupiter and Venus (north up) as they would be seen in a small telescope with the same magnification. On the evening of the September 10th 2025, Saturn will be 19.4″ in diameter, but its rings, even being nearly edge on, should show up brighter than seen here, and extend to 45.2″. They are tilted 2.2° from being edge on. On the morning of the September 11th 2025, Jupiter will be 35.1″ in diameter. Earlier in the morning Io and its shadow will transit the face of Jupiter. Venus’ apparent diameter will be 11.8″, and be 86.9% illuminated. The (”) symbol means seconds of arc, or 1/3600th of a degree. Created using Cartes du Ciel (Sky Charts), LibreOffice Draw and GIMP.
The naked-eye planets and the Moon at sunset and sunrise on a single night
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on September 10th, 2025. The night ends on the left with sunrise on the 11th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
A low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow
This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, September 10th and 11th, 2025. Some of the columns are self-explanatory, others are not. The transit column is the time that the body crosses the meridian and is due south. Elong, for elongation, is the angle between the Sun and that body. RA is right ascension, which is the object’s east-west position on the celestial sphere in hours and minutes. Dec is declination which is the north-south position of the object on the celestial sphere in degrees and minutes. R is the distance of that object from the Sun in astronomical units. An astronomical unit is about 93 million miles or 150 million kilometers. And Delta is the distance of that object from the Earth, also in astronomical units. I omit the ‘m’ in am and pm for compactness. The data was generated using my LookingUp for DOS app and displayed as a table by my Ephemeris Helper app.
Categories: Ephemeris Program, Naked-eye planets, Observing Tags: , , , , ,

Ephemeris: 09/09/2025 – 3I/ATLAS, a minority view

September 9, 2025 Comments off

This is Ephemeris for Tuesday, September 9th. Today the Sun will be up for 12 hours and 49 minutes, setting at 8:04, and it will rise tomorrow at 7:16. The Moon, 2 days past full, will rise at 8:51 this evening.

Interstellar object 3I/ATLAS is closing in on the planet Mars, which it will reach nearest to on October 1st. Some speculate, including one Harvard professor, that maybe it’s an alien probe. This object is much too slow to traverse the interstellar medium between stars with a biological crew, who are short-lived like us. More likely it would be crewed by robots run by artificial intelligence, like which we are beginning to perfect. 3I/ATLAS will not get very close to the Earth, but will get close to Mars. That got me to speculating, tongue in cheek of course, that being a machine intelligence they would be more interested in Mars. The reason being, that Mars is the only planet that’s entirely inhabited by robots, like themselves.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

nterstellar object 3I/ATLAS aka C/2025 N1 (ATLAS) seen as it will pass Mars around October 1, 2025.
Interstellar object 3I/ATLAS aka C/2025 N1 (ATLAS) seen as it will pass Mars around October 1, 2025. Our best look at it then will come from the Mars Reconnaissance Orbiter. Credit: NASA/JPL Small-Body Database.
Having a little fun: What if the AI robot on 3I/ATLAS was checking out Mars?
Having a little fun: What if the AI robot on 3I/ATLAS was checking out Mars? This is a Copilot produced image. I tried also with Grok. I could get neither robot to turn around and actually look at Mars.

Categories: Comet, Ephemeris Program, Interstellar visitor, Speculation Tags: ,

Ephemeris: 09/05/2025 – GTAS meeting tonight, a personal view of nebulae, interstellar clouds

September 5, 2025 Comments off

This is Ephemeris for Friday, September 5th. Today the Sun will be up for 13 hours and 1 minute, setting at 8:11, and it will rise tomorrow at 7:11. The Moon, 2 days before full, will set at 5:36 tomorrow morning.

The Grand Traverse Astronomical Society will host its September meeting tonight at 8 PM at Northwestern Michigan College’s Joseph H Rogers Observatory. The talk for the evening will be given by Daniel Dall’Olmo, one of our members, who has had great success photographing the wonders of the universe. He will show and discuss the different types of nebulae he’s photographed. After the meeting, weather permitting, there will be viewing of the Moon and whatever we can find in the twilight. The observatory is located south of Traverse City on Birmley Rd. The meeting will also be available via Zoom, with instructions for joining the meeting on the society’s website, http://www.gtastro.org.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Great Orion Nebula
The Great Orion Nebula, the birthplace of stars, along with some dark dusty nebulae. Credit: Daniel Dall’Olmo.
The Ring Nebula, M57
The Ring Nebula, M57, the result of a Sun size star near the end of life expelling its outer layers of gas. These are called planetary nebulae because some look like the distant planets Uranus or Neptune visually in telescopes. Credit: Daniel Dall’Olmo,
The Crab Nebula, M1
The Crab Nebula, M1, a supernova remnant. The star was seen to explode in 1054 CE. Credit: Daniel Dall’Olmo.
Categories: Ephemeris Program, GTAS Outreach Event, Nebulae Tags:

Ephemeris: 09/04/2025 – Venus, the Morning Star

September 4, 2025 Comments off

This is Ephemeris for Thursday, September 4th. Today the Sun will be up for 13 hours and 4 minutes, setting at 8:13, and it will rise tomorrow at 7:10. The Moon, 3 days before full, will set at 4:19 tomorrow morning.

Venus graces our morning sky as the Morning Star. It is seen, this year, along with the planet Jupiter. They are the two brightest planets. The Greek and others of that part of the world, early on, thought the evening and morning appearances of Venus were two different planets. The Mayans of Pre-Columbian Central America were meticulous observers of Venus, as is seen in one of their surviving books, the Dresden Codex. A Venus cycle lasts 584 days, from first appearance in the morning sky, its heliacal rising, through its morning appearance, disappearance behind the Sun, through its evening appearance and disappearance to the next heliacal rising. Astronomers call that it’s synodic period. Five synodic periods equal almost exactly 8 years.

Addendum

The Venus Cycle as seen by the Mayans.
The Venus Cycle as seen by the Mayans. In the gray part of the cycle Venus in unobservable due to being too close to the Sun in the sky.
Perspective view of Venus’ orbit in relation to the Earth, showing change in phase and size with position. When Venus is on the right side of the Sun, it is visible in the morning sky, on the left in the evening. The numbers represent Venus’ apparent size in seconds of arc. The image was found on the Internet, uncredited from a defunct website.
Categories: Concepts, Ephemeris Program, Observing Tags: ,

Ephemeris: 09/03/2025 – Our weekly look at the naked-eye planets

September 3, 2025 2 comments

This is Ephemeris for Wednesday, September 3rd. Today the Sun will be up for 13 hours and 7 minutes, setting at 8:15, and it will rise tomorrow at 7:09. The Moon, 3 days past first quarter, will set at 3:04 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. The Red Planet Mars is too close to the direction of the Sun to spot. This is the curse of trying to view evening planets, which are near the direction of the Sun in late summer and early fall, for us at higher latitudes. Saturn now rises at 8:58 PM in the east. In a telescope Saturn sports a very thin ring, 2 ½° from being edge on. This angle will decrease to about a third of a degree by November 23rd before increasing. By 6 AM Saturn will be in the southwest. Jupiter will appear above the brighter Venus in the eastern sky and among the stars of Gemini. Venus and Jupiter are joining the bright winter stars, a beautiful sight in the morning twilight.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Saturn and the Moon at 10 PM tonight
Saturn and the Moon at 10 PM tonight, September 3, 2025. Created using Stellarium.
The Moon tonight, September 3, 2025. A view visible in small telescopes showing an image with and without selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
Venus and Jupiter are visible in the east among the winter stars at 6:00 AM tomorrow morning
Venus and Jupiter are visible in the east among the winter stars at 6:00 AM tomorrow morning, September 4, 2025. Saturn is off in the west-southwest. Created using Stellarium and GIMP.
Telescopic Saturn, Jupiter and Venus (north up) as they would be seen in a small telescope with the same magnification.
Telescopic Saturn, Jupiter and Venus (north up) as they would be seen in a small telescope with the same magnification. On the evening of the September 3rd 2025, Saturn will be 19.4″ in diameter, but its rings, even being nearly edge on, should show up brighter than seen here, and extend to 45.1″. They are tilted 2.5° from being edge on. On the morning of the September 4th 2025, Jupiter will be 35.0″ in diameter. Venus’ apparent diameter will be 12.1″, and be 85.2% illuminated. The (”) symbol means seconds of arc, or 1/3600th of a degree. Created using Cartes du Ciel (Sky Charts), LibreOffice Draw and GIMP.
The naked-eye planets and the Moon at sunset and sunrise on a single night
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on September 3rd, 2025. The night ends on the left with sunrise on the 4th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
A low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow
This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, September 3rd and 4th, 2025. Some of the columns are self-explanatory, others are not. The transit column is the time that the body crosses the meridian and is due south. Elong, for elongation, is the angle between the Sun and that body. RA is right ascension, which is the object’s east-west position on the celestial sphere in hours and minutes. Dec is declination which is the north-south position of the object on the celestial sphere in degrees and minutes. R is the distance of that object from the Sun in astronomical units. An astronomical unit is about 93 million miles or 150 million kilometers. And Delta is the distance of that object from the Earth, also in astronomical units. I omit the ‘m’ in am and pm for compactness. The data was generated using my LookingUp for DOS app and displayed as a table by my Ephemeris Helper app.

Categories: Ephemeris Program, Naked-eye planets, Observing Tags: , , , , ,

Ephemeris: 09/02/2025 – 3I/ATLAS, interstellar visitor

September 2, 2025 Comments off

This is Ephemeris for Tuesday, September 2nd. Today the Sun will be up for 13 hours and 10 minutes, setting at 8:17, and it will rise tomorrow at 7:07. The Moon, 2 days past first quarter, will set at 1:54 tomorrow morning.

Interstellar visitor 3I/ATLAS was discovered a couple of months ago. We are lucky because it was discovered on its way into the inner solar system. The first interstellar visitor, 1I/‘Oumuamua, we didn’t spot until it had already passed and on its way out. It turns out that the chemical composition of this interstellar visitor, which astronomers think is a comet, has a great deal of carbon dioxide in its atmosphere compared to water. In the universe water is the third most common molecule after diatomic hydrogen and diatomic oxygen. But this comet appears to have about 8 times more carbon dioxide than water. Some astronomers think the 3I/ATLAS is 3 billion years older than the solar system making it 7 1/2 billion years old.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Interstellar comet 3I/ATLAS imaged by the Hubble Space Telescope. The telescope was tracking the comet during the time exposure, causing the stars to trail. Credit NASA/HST.
A diagram showing the position of 3I/ATLAS for the 2nd of July 2025. Its designation here is the discovery designation: C for comet, 2025 the year, and N for the first half of July, 1 the first object discovered in that period, and the name of the person or organization that discovered it . Note that the comet will come fairly close to Mars. The Mars Reconnaissance Orbiter is going to be observing the comet as it passes Mars next month. Credit: NASA/JPL.
Categories: Astronomy News, Comet, Ephemeris Program Tags: ,

Ephemeris: 09/01/2025 – Previewing September skies

September 1, 2025 Comments off

This is Ephemeris for Labor Day, Monday, September 1st. Today the Sun will be up for 13 hours and 13 minutes, setting at 8:18, and it will rise tomorrow at 7:06. The Moon, 1 day past first quarter, will set at 12:52 tomorrow morning.

Let’s look at the skies for the month of September. The sun will be moving at its greatest speed in its retreat to the south. Daylight hours in the Interlochen/Traverse City area and will drop from 13 hours and 13 minutes today to 11 hours and 44 minutes on the 30th. The altitude of the Sun above the southern horizon at local noon will be 54 degrees today, and will descend to 42 degrees on the 30th. Local noon at mid-month will be around 1:37 pm. The season of summer is getting short, so enjoy it while you can. Summer ends and autumn begins at 2:20 PM on September 22nd, the autumnal equinox. This year the Harvest Moon, the nearest full moon to the equinox, will fall next month, this month it’s the Corn Moon.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

September Evening Star Chart

Star Chart for September 2025
Star Chart for September 2025 (10 PM EDT, September 15). Click on the image to enlarge it. Created using my LookingUp program.

The planets and stars are plotted for the 15th at 10 p.m. EDT in the evening and 6 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.

September Morning Star Chart

Star Chart for September 2025 (6 am EDT, September 15). Click on the image to enlarge it. Created using my LookingUp program.

For a list of constellation names to go with the abbreviations, click here.

  • Pointer stars at the front of the bowl of the Big Dipper point to Polaris, the North Star.
  • Leaky dipper drips on Leo.
  • Follow the arc of the handle of the Big Dipper to the star Arcturus.
  • The Summer Triangle is in red.

Twilight Limits, Nautical and Astronomical

      EDT        
  Morning Twilight Evening Twilight Dark Night Moon
Date Astro. Nautical Nautical Astro. Start End Illum.
2025-09-01 5h23m 6h01m 21h28m 22h06m 0h01m 5h23m 0.68
2025-09-02 5h24m 6h02m 21h26m 22h04m 0h53m 5h24m 0.77
2025-09-03 5h26m 6h04m 21h24m 22h02m 1h54m 5h26m 0.85
2025-09-04 5h27m 6h05m 21h22m 22h00m 3h05m 5h27m 0.92
2025-09-05 5h29m 6h06m 21h20m 21h58m 4h20m 5h29m 0.97
2025-09-06 5h30m 6h08m 21h18m 21h55m – – 1.00
2025-09-07 5h32m 6h09m 21h16m 21h53m – – 1.00
2025-09-08 5h33m 6h10m 21h14m 21h51m – – 0.97
2025-09-09 5h35m 6h12m 21h12m 21h49m – – 0.92
2025-09-10 5h36m 6h13m 21h10m 21h47m – – 0.84
2025-09-11 5h38m 6h14m 21h08m 21h44m – – 0.75
2025-09-12 5h39m 6h16m 21h06m 21h42m 21h42m 22h19m 0.64
2025-09-13 5h41m 6h17m 21h04m 21h40m 21h40m 23h06m 0.53
2025-09-14 5h42m 6h18m 21h02m 21h38m 21h38m – 0.41
2025-09-15 5h44m 6h19m 21h00m 21h36m 21h36m 0h05m 0.31
2025-09-16 5h45m 6h21m 20h58m 21h34m 21h34m 1h15m 0.21
2025-09-17 5h46m 6h22m 20h56m 21h32m 21h32m 2h29m 0.13
2025-09-18 5h48m 6h23m 20h54m 21h29m 21h29m 3h44m 0.07
2025-09-19 5h49m 6h25m 20h52m 21h27m 21h27m 4h57m 0.03
2025-09-20 5h51m 6h26m 20h50m 21h25m 21h25m 5h51m 0.00
2025-09-21 5h52m 6h27m 20h48m 21h23m 21h23m 5h52m 0.00
2025-09-22 5h53m 6h28m 20h46m 21h21m 21h21m 5h53m 0.02
2025-09-23 5h55m 6h30m 20h44m 21h19m 21h19m 5h55m 0.05
2025-09-24 5h56m 6h31m 20h42m 21h17m 21h17m 5h56m 0.10
2025-09-25 5h57m 6h32m 20h40m 21h15m 21h15m 5h57m 0.17
2025-09-26 5h59m 6h33m 20h38m 21h13m 21h20m 5h59m 0.25
2025-09-27 6h00m 6h35m 20h36m 21h11m 21h56m 6h00m 0.33
2025-09-28 6h01m 6h36m 20h35m 21h09m 22h43m 6h01m 0.42
2025-09-29 6h03m 6h37m 20h33m 21h07m 23h39m 6h03m 0.52
2025-09-30 6h04m 6h38m 20h31m 21h05m – 6h04m 0.62

Twilight calendar was generated using Cartes du Ciel (Sky Charts).

See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.

NASA Calendar of Planetary Events

Sep  1  Mo            Venus: 31.2° W
     1  Mo   6:04 PM  Moon South Dec.: 28.6° S
     7  Su   2:09 PM  Full Moon
     7  Su   2:13 PM  Total Lunar Eclipse
     7  Su   7:08 PM  Moon Ascending Node
     8  Mo   4:09 PM  Moon-Saturn: 4° S
    10  We   8:10 AM  Moon Perigee: 364800 km
    12  Fr   5:48 PM  Moon-Pleiades: 1° S
    12  Fr  11:28 PM  Mars-Spica: 2.2° N
    13  Sa   6:46 AM  Mercury Superior Conjunction
    14  Su   6:33 AM  Last Quarter
    14  Su   5:23 PM  Moon North Dec.: 28.6° N
    16  Tu   7:06 AM  Moon-Jupiter: 4.7° S
    16  Tu   1:58 PM  Moon-Pollux: 2.5° N
    17  We   1:24 PM  Moon-Beehive: 2.1° S
    19  Fr   4:59 AM  Venus-Regulus: 0.5° N
    19  Fr   7:11 AM  Moon-Regulus: 1.4° S
    19  Fr   7:46 AM  Moon-Venus: 0.9° S
    20  Sa   7:13 PM  Moon Descending Node
    21  Su   1:10 AM  Saturn Opposition
    21  Su   3:42 PM  Partial Solar Eclipse (Not here.
                      In New Zealand and Antarctica)
    21  Su   3:54 PM  New Moon
    22  Mo   2:20 PM  Autumnal Equinox
    23  Tu   7:29 AM  Neptune Opposition
    23  Tu   5:31 PM  Moon-Spica: 1.2° N
    24  We  10:50 AM  Moon-Mars: 4.3° N
    26  Fr   5:46 AM  Moon Apogee: 405600 km
    27  Sa   1:34 PM  Moon-Antares: 0.7° N
    29  Mo   2:09 AM  Moon South Dec.: 28.6° S
    29  Mo   7:54 PM  First Quarter
Oct  1  We            Venus: 23.9° W

Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC), with modifications by the author.
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.

If you go to the above site, you can print out a list like the above for the entire year or calendar pages for your time zone.

Sun and Moon Rising and Setting Events

LU             Ephemeris of Sky Events for Interlochen/TC
September, 2025    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Mon  1| 07:05a  08:18p  13:13 | 09:24p  05:59a |      Set  12:52a   66%|
|Tue  2| 07:06a  08:17p  13:10 | 09:22p  06:00a |      Set  01:54a   75%|
|Wed  3| 07:07a  08:15p  13:07 | 09:20p  06:01a |      Set  03:04a   84%|
|Thu  4| 07:09a  08:13p  13:04 | 09:18p  06:03a |      Set  04:19a   91%|
|Fri  5| 07:10a  08:11p  13:01 | 09:16p  06:04a |      Set  05:36a   96%|
|Sat  6| 07:11a  08:09p  12:58 | 09:14p  06:06a |      Set  06:53a   99%|
+------+-----------------------+----------------+-----------------------+
|Sun  7| 07:12a  08:07p  12:55 | 09:12p  06:07a |Full  Rise 08:10p  100%|
|Mon  8| 07:13a  08:05p  12:52 | 09:10p  06:08a |      Rise 08:30p   98%|
|Tue  9| 07:14a  08:04p  12:49 | 09:08p  06:10a |      Rise 08:51p   93%|
|Wed 10| 07:16a  08:02p  12:46 | 09:06p  06:11a |      Rise 09:14p   86%|
|Thu 11| 07:17a  08:00p  12:43 | 09:04p  06:12a |      Rise 09:43p   77%|
|Fri 12| 07:18a  07:58p  12:39 | 09:02p  06:14a |      Rise 10:19p   66%|
|Sat 13| 07:19a  07:56p  12:36 | 09:00p  06:15a |      Rise 11:06p   55%|
+------+-----------------------+----------------+-----------------------+
|Sun 14| 07:20a  07:54p  12:33 | 08:58p  06:16a |L Qtr Rise 12:05a   44%|
|Mon 15| 07:22a  07:52p  12:30 | 08:56p  06:17a |      Rise 01:14a   33%|
|Tue 16| 07:23a  07:50p  12:27 | 08:54p  06:19a |      Rise 02:29a   23%|
|Wed 17| 07:24a  07:49p  12:24 | 08:52p  06:20a |      Rise 03:44a   15%|
|Thu 18| 07:25a  07:47p  12:21 | 08:50p  06:21a |      Rise 04:56a    8%|
|Fri 19| 07:26a  07:45p  12:18 | 08:48p  06:23a |      Rise 06:06a    3%|
|Sat 20| 07:27a  07:43p  12:15 | 08:46p  06:24a |      Rise 07:13a    1%|
+------+-----------------------+----------------+-----------------------+
|Sun 21| 07:29a  07:41p  12:12 | 08:44p  06:25a |New   Set  07:33p    0%|
|Mon 22| 07:30a  07:39p  12:09 | 08:42p  06:26a |      Set  07:50p    1%|
|Tue 23| 07:31a  07:37p  12:06 | 08:40p  06:28a |      Set  08:07p    4%|
|Wed 24| 07:32a  07:35p  12:03 | 08:38p  06:29a |      Set  08:27p    9%|
|Thu 25| 07:33a  07:33p  12:00 | 08:37p  06:30a |      Set  08:50p   15%|
|Fri 26| 07:35a  07:32p  11:56 | 08:35p  06:31a |      Set  09:19p   23%|
|Sat 27| 07:36a  07:30p  11:53 | 08:33p  06:33a |      Set  09:56p   31%|
+------+-----------------------+----------------+-----------------------+
|Sun 28| 07:37a  07:28p  11:50 | 08:31p  06:34a |      Set  10:42p   40%|
|Mon 29| 07:38a  07:26p  11:47 | 08:29p  06:35a |F Qtr Set  11:38p   50%|
|Tue 30| 07:39a  07:24p  11:44 | 08:27p  06:36a |      Set  12:44a   60%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise

Generated using my LookingUp for DOS app.

Categories: Ephemeris Program, Month preview

Ephemeris: 08/29/2025 – Late August crescent Moon stays low in the western sky

August 29, 2025 Comments off

This is Ephemeris for Friday, August 29th. Today the Sun will be up for 13 hours and 22 minutes, setting at 8:24, and it will rise tomorrow at 7:03. The Moon, 2 days before first quarter, will set at 10:48 this evening.

There’s an interesting feature that I’ve noticed about the Moon this time of year. When there’s a waxing crescent Moon in the evening, in late summer to early autumn, it’s seen pretty low in the southwestern sky after sunset. Tonight it’ll be two days before first quarter so it’ll be a fat crescent. However, when it’s seen after sunset, it will be very low in the southwestern sky. Contrast that for early risers, at this time of year the waning crescent Moon moves at a steep angle to the horizon, as do the planets now in the east. And of course the opposite is true for late winter and early spring moons. By the way, the Harvest Moon is in early October this year. The Harvest Moon is the nearest full moon to the autumnal equinox.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Daily position of the crescent Moon on four dates in late August, 2025. The Moon is shown 3 times normal size for clarity. Created using Stellarium, GIMP and LibreOffice Draw.
This is the planert and Moon line up from the morning of a couple of weeks ago. Note the steep line of the planets. The Planets motion closely follows the ecliptic (Sun’s path) as does the Moon.

Categories: Concepts, Ephemeris Program, Observing, Planets, The Moon