Archive
Ephemeris: 08/03/2026 – The Milky Way, a spiral galaxy with a bar
This is Ephemeris for Monday, August 3rd. Today the Sun will be up for 14 hours and 34 minutes, setting at 9:05, and it will rise tomorrow at 6:32. The Moon, 2 days before last quarter, will rise at 11:07 this evening.
The Milky Way is classed as a barred spiral galaxy. It has an apparent spiral structure in its disk illuminated by bright massive short lived stars that don’t stray far from the nebulae they were born from. Nebulae, mostly dark, form the backbone of the spiral structure. The Andromeda Galaxy is also a spiral, a little larger than our Milky Way Galaxy. Dwarf galaxies like the Magellanic clouds which are seen from the southern hemisphere of the earth that happen to be satellites of the Milky Way, and are irregular in shape. A third type of galaxy is the elliptical galaxy, many of which are extremely large and contain pretty much nothing but old stars, and no nebulosity to make new ones.
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
Ephemeris: 07/31/2026 – Previewing August skies
This is Ephemeris for Friday, July 31st. Today the Sun will be up for 14 hours and 41 minutes, setting at 9:09, and it will rise tomorrow at 6:29. The Moon, 2 days past full, will rise at 10:12 this evening.
Let’s look ahead at the month of August in the skies. Daylight hours will decrease from 14 hours and 39 minutes tomorrow to 13 hours 17 minutes on the 31st. The altitude of the Sun at local noon, that is degrees of angle above the southern horizon, will decrease from 63 degrees tomorrow to just over 53 degrees on the 31st. Straits area listeners can subtract one more degree from those angles. Local noon, when the Sun is due south, is about 1:43 p.m. During August we have 3 astronomical events occurring. The first is August 12th, a double header: during the day a little nibble of a solar eclipse and in the evening the peak of the Perseid meteor shower, generally the best of the year, for us. And late night on the 27th we have an eclipse of the Moon that will be almost total.
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
August Evening Star Chart
The planets and stars are plotted for the 15th at 10 PM EDT in the evening and 4:30 AM on the 16th for the morning chart. These are the chart times. Note that Interlochen/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.
Note, the chart times of 10 PM and 4:30 AM are for the 15th & 16th respectively. For each week before these dates, add ½ hour (28 minutes if you’re picky). For each week after the 15th, subtract ½ hour, or 28 minutes. The planet positions are updated each Wednesday on this blog.
August Morning Star Chart
Twilight Limits, Nautical and Astronomical
| EDT | |||||||
| Morning | Twilight | Evening | Twilight | Dark | Night | Moon | |
| Date | Astro. | Nautical | Nautical | Astro. | Start | End | Illum. |
| 2026-08-01 | 4h27m | 5h15m | 22h27m | 23h15m | – | – | 87% |
| 2026-08-02 | 4h29m | 5h17m | 22h25m | 23h13m | – | – | 80% |
| 2026-08-03 | 4h31m | 5h18m | 22h24m | 23h11m | – | – | 70% |
| 2026-08-04 | 4h33m | 5h20m | 22h22m | 23h09m | 23h09m | 23h30m | 60% |
| 2026-08-05 | 4h35m | 5h21m | 22h20m | 23h07m | 23h07m | 23h57m | 49% |
| 2026-08-06 | 4h36m | 5h23m | 22h18m | 23h05m | 23h05m | – | 38% |
| 2026-08-07 | 4h38m | 5h24m | 22h17m | 23h02m | 23h02m | 0h33m | 27% |
| 2026-08-08 | 4h40m | 5h26m | 22h15m | 23h00m | 23h00m | 1h20m | 17% |
| 2026-08-09 | 4h42m | 5h27m | 22h13m | 22h58m | 22h58m | 2h22m | 9% |
| 2026-08-10 | 4h44m | 5h29m | 22h11m | 22h56m | 22h56m | 3h36m | 3% |
| 2026-08-11 | 4h46m | 5h30m | 22h10m | 22h54m | 22h54m | 4h46m | 0% |
| 2026-08-12 | 4h48m | 5h32m | 22h08m | 22h52m | 22h52m | 4h48m | 0% |
| 2026-08-13 | 4h50m | 5h33m | 22h06m | 22h49m | 22h49m | 4h50m | 3% |
| 2026-08-14 | 4h51m | 5h35m | 22h04m | 22h47m | 22h47m | 4h51m | 8% |
| 2026-08-15 | 4h53m | 5h36m | 22h02m | 22h45m | 22h45m | 4h53m | 15% |
| 2026-08-16 | 4h55m | 5h38m | 22h00m | 22h43m | 22h43m | 4h55m | 23% |
| 2026-08-17 | 4h57m | 5h39m | 21h58m | 22h41m | 22h42m | 4h57m | 32% |
| 2026-08-18 | 4h59m | 5h41m | 21h56m | 22h38m | 23h06m | 4h59m | 41% |
| 2026-08-19 | 5h00m | 5h42m | 21h55m | 22h36m | 23h35m | 5h00m | 51% |
| 2026-08-20 | 5h02m | 5h43m | 21h53m | 22h34m | – | 5h02m | 61% |
| 2026-08-21 | 5h04m | 5h45m | 21h51m | 22h32m | 0h12m | 5h04m | 70% |
| 2026-08-22 | 5h06m | 5h46m | 21h49m | 22h29m | 0h57m | 5h06m | 78% |
| 2026-08-23 | 5h07m | 5h48m | 21h47m | 22h27m | 1h51m | 5h07m | 85% |
| 2026-08-24 | 5h09m | 5h49m | 21h45m | 22h25m | 2h52m | 5h09m | 91% |
| 2026-08-25 | 5h11m | 5h51m | 21h43m | 22h23m | 3h58m | 5h11m | 96% |
| 2026-08-26 | 5h12m | 5h52m | 21h41m | 22h20m | 5h07m | 5h12m | 99% |
| 2026-08-27 | 5h14m | 5h53m | 21h39m | 22h18m | – | – | 100% |
| 2026-08-28 | 5h16m | 5h55m | 21h37m | 22h16m | – | – | 99% |
| 2026-08-29 | 5h17m | 5h56m | 21h35m | 22h14m | – | – | 95% |
| 2026-08-30 | 5h19m | 5h58m | 21h33m | 22h11m | – | – | 90% |
| 2026-08-31 | 5h21m | 5h59m | 21h31m | 22h09m | – | – | 82% |
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
Aug 1 Sa Venus: 45.3° E
2 Su 3:59 AM Mercury Elongation: 19.5° W
5 We 10:21 PM Last Quarter
7 Fr 2:23 AM Moon-Pleiades: 1.2° S
8 Sa 7:42 PM Moon North Dec.: 28.1° N
9 Su 1:31 AM Moon-Mars: 4.4° S
10 Mo 7:18 AM Moon Perigee: 363300 km
12 We 1:37 PM New Moon
12 We 1:47 PM Total Solar Eclipse
11% Partial Solar Eclipse in N. Michigsn
12 We 9:56 PM Perseid Shower: ZHR = 90
13 Th 5:56 AM Moon Descending Node
15 Sa 1:59 AM Venus Elongation: 45.9° E
16 Su 4:46 AM Moon-Venus: 2.2° N
17 Mo 7:49 AM Moon-Spica: 2.6° N
19 We 10:46 PM First Quarter
21 Fr 12:17 AM Moon-Antares: 0.7° N
22 Sa 4:20 AM Moon Apogee: 404600 km
22 Sa 6:59 AM Moon South Dec.: 28.1° S
27 Th 12:44 PM Mercury Superior Conjunction
27 Th 2:47 PM Moon Ascending Node
28 Fr 12:14 AM Partial Lunar Eclipse
28 Fr 12:18 AM Full Moon
Sep 1 Tu Venus: 44.6° E
All event times are given for UTC-4:00 Eastern Daylight Saving Time.
Events in bold will be covered in subsequent posts on this blog. Also, the August 2026 issue of the Grand Traverse Astronomical Society’s Stellar Sentinel contains an article I wrote about them. Access it here when it is published in a few days.
Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
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.
Note that the site is now kept up for archival purposes. Fred Espenak retired from NASA several years ago and has his own site, AstroPixels, which contain the same information: http://astropixels.com/almanac/almanac.html. However, it uses standard time all year.
Fred passed away a year ago, on June 1, 2025. RIP.
Sun and Moon Rising and Setting Events
LU Ephemeris of Sky Events for Interlochen/TC
August, 2026 Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM |
| | RISE SET HOURS | END START |PHASE SET** TIME FRACTN|
+=======================================================================+
|Sat 1| 06:29a 09:08p 14:39 | 10:23p 05:13a | Rise 10:30p 89%|
+------+-----------------------+----------------+-----------------------+
|Sun 2| 06:30a 09:07p 14:36 | 10:22p 05:14a | Rise 10:48p 81%|
|Mon 3| 06:31a 09:05p 14:34 | 10:20p 05:16a | Rise 11:07p 72%|
|Tue 4| 06:32a 09:04p 14:32 | 10:18p 05:17a | Rise 11:29p 62%|
|Wed 5| 06:33a 09:03p 14:29 | 10:17p 05:19a |L Qtr Rise 11:57p 51%|
|Thu 6| 06:34a 09:01p 14:26 | 10:15p 05:20a | Rise 12:32a 40%|
|Fri 7| 06:35a 09:00p 14:24 | 10:13p 05:22a | Rise 01:20a 29%|
|Sat 8| 06:37a 08:58p 14:21 | 10:11p 05:23a | Rise 02:21a 19%|
+------+-----------------------+----------------+-----------------------+
|Sun 9| 06:38a 08:57p 14:19 | 10:10p 05:25a | Rise 03:36a 10%|
|Mon 10| 06:39a 08:56p 14:16 | 10:08p 05:26a | Rise 04:58a 4%|
|Tue 11| 06:40a 08:54p 14:13 | 10:06p 05:28a | Rise 06:22a 1%|
|Wed 12| 06:41a 08:53p 14:11 | 10:04p 05:29a |New Set 09:00p 0%|
|Thu 13| 06:42a 08:51p 14:08 | 10:02p 05:31a | Set 09:22p 2%|
|Fri 14| 06:44a 08:49p 14:05 | 10:00p 05:32a | Set 09:42p 7%|
|Sat 15| 06:45a 08:48p 14:03 | 09:58p 05:34a | Set 10:01p 13%|
+------+-----------------------+----------------+-----------------------+
|Sun 16| 06:46a 08:46p 14:00 | 09:57p 05:35a | Set 10:20p 21%|
|Mon 17| 06:47a 08:45p 13:57 | 09:55p 05:37a | Set 10:41p 30%|
|Tue 18| 06:48a 08:43p 13:54 | 09:53p 05:38a | Set 11:05p 39%|
|Wed 19| 06:50a 08:41p 13:51 | 09:51p 05:40a |F Qtr Set 11:35p 49%|
|Thu 20| 06:51a 08:40p 13:49 | 09:49p 05:41a | Set 12:11a 58%|
|Fri 21| 06:52a 08:38p 13:46 | 09:47p 05:43a | Set 12:56a 68%|
|Sat 22| 06:53a 08:36p 13:43 | 09:45p 05:44a | Set 01:50a 76%|
+------+-----------------------+----------------+-----------------------+
|Sun 23| 06:54a 08:35p 13:40 | 09:43p 05:46a | Set 02:51a 84%|
|Mon 24| 06:55a 08:33p 13:37 | 09:41p 05:47a | Set 03:57a 90%|
|Tue 25| 06:57a 08:31p 13:34 | 09:39p 05:49a | Set 05:06a 95%|
|Wed 26| 06:58a 08:30p 13:31 | 09:37p 05:50a | Set 06:15a 99%|
|Thu 27| 06:59a 08:28p 13:28 | 09:35p 05:51a | Set 07:25a 100%|
|Fri 28| 07:00a 08:26p 13:25 | 09:33p 05:53a |Full Rise 08:36p 99%|
|Sat 29| 07:01a 08:24p 13:22 | 09:31p 05:54a | Rise 08:54p 96%|
+------+-----------------------+----------------+-----------------------+
|Sun 30| 07:02a 08:22p 13:19 | 09:29p 05:56a | Rise 09:14p 91%|
|Mon 31| 07:04a 08:21p 13:17 | 09:27p 05:57a | Rise 09:35p 84%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise
Generated using my LookingUp for DOS app.
Ephemeris: 07/30/2026 – The types and distribution of galaxies
This is Ephemeris for Thursday, July 30th. Today the Sun will be up for 14 hours and 44 minutes, setting at 9:10, and it will rise tomorrow at 6:27. The Moon, 1 day past full, will rise at 9:52 this evening.
Until a little over 100 years ago the Milky Way was thought to be the whole universe. Then with photography the great Andromeda nebula turned out to be not a cloud of gas but a great group of stars outside. Since then we have found billions upon billions of these galaxies. Galaxy simply is a derivation from “Milky Way” in Latin. Galaxies are not sprinkled through the universe uniformly. They appear in great clusters and in small groups. The Milky Way and the Andromeda Galaxy belong to a relatively small group of galaxies called the Local Group, which contains 130 or more, mostly dwarf galaxies of which Andromeda and our Milky Way are the largest. The Great Andromeda Galaxy will come in view into the evening sky 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.
Addendum
Ephemeris: 07/29/2026 – Taking our weekly look at the whereabouts of the naked-eye planets
This is Ephemeris for Wednesday, July 29th. Today the Sun will be up for 14 hours and 46 minutes, setting at 9:12, and it will rise tomorrow at 6:26. The Moon, at full today, will rise at 9:30 this evening.
Let’s take our weekly look at the whereabouts of the naked-eye planets. By 9:45 PM tonight, a bit over a half-hour after sunset, Venus will be easily spotted in the western sky. A telescope will show a tiny gibbous disc of Venus. It is now closer than the Sun, at 76.5 million miles (123.3 mil km) away from us. We are 18 days from Venus greatest elongation east from the sun of 45.9 degrees. It’s within a degree of that now. In the morning, Saturn and Mars will be visible in the southeast and east respectively. Mars is competing with the brighter stars of winter, including the orange Aldebaran, and the red giant star Betelgeuse. The Earth is now chasing down Mars, which will be closest to the Earth and opposite the sun in the sky next February.
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
Ephemeris: 07/28/2026 – The size and shape of the Milky Way
7/
This is Ephemeris for Tuesday, July 28th. Today the Sun will be up for 14 hours and 48 minutes, setting at 9:13, and it will rise tomorrow at 6:25. The Moon, 1 day before full, will set at 6:11 tomorrow morning.
August and September are the two months in which the Milky Way dominates the evening sky. It also dominates the sky in the winter, six months from now but we’re looking out away from the center of the Milky Way. It is dimmer, an almost invisible as a band, but we have a great number of really bright stars, including those of Orion. The Milky Way is a galaxy, a large conglomeration of stars that are arranged in a disk, with the central bulge, whose diameter is about 87,400 light years. The thickness of the disk runs from 8,500 light years near the center to 1,000 light years farther out. The sun’s location is 25 to 26,000 light years from the center. From our location within the disk it appears to be a glowing band that surrounds the sky.
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
Ephemeris: 07/27/2026 – Can you trust chat bot answers?
This is Ephemeris for Monday, July 27th. Today the Sun will be up for 14 hours and 50 minutes, setting at 9:14, and it will rise tomorrow at 6:24. The Moon, 2 days before full, will set at 5:04 tomorrow morning.
What science fiction TV shows and movies get artificial intelligence or intelligent computers all wrong at least before 2001 A Space Odyssey, was if they don’t know the answer they will give you: a “THIS DOES NOT COMPUTE”. Current artificial intelligence large language models will rarely admit that they don’t know or can’t find an answer. It will give you something, even if it is not correct. It’s called halucinating. Sounds like lying to me. They’re called chat bots, because they are made to sound human, and can be very seductive. However, they are alien minds, as if space aliens learned about us by monitoring our radio, TV and internet. AI’s are trained on Internet content. You know what a swamp that is!
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
If a chat bot gives you references, follow them up. once when doing research on something, Google’s Gemini referenced an old post on this site. I also caught it in an error, and told it so. It told me I was right.
Ephemeris: 07/24/2026 – AI, a paradigm shift in computing
This is Ephemeris for Friday, July 24th. Today the Sun will be up for 14 hours and 57 minutes, setting at 9:17, and it will rise tomorrow at 6:21. The Moon, 3 days past first quarter, will set at 2:15 tomorrow morning.
Astronomy is my hobby. Back in my working days I was a computer systems analyst designing computer software systems for particular tasks, mainly for banks. However I was always interested in the idea of artificial intelligence. The computers I worked with were dumb. They did exactly what you told it to do, whether it was correct or not. So computer errors were really human errors. The current AI, based on neural networks, which are an approximation of what happens in the human brain, are different. Their errors are their own, because they are taught rather than programmed. And to my mind are more than the sum of their inputs. Even the people who design these systems admit they don’t really know what goes on inside. Scary.
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.
Ephemeris: 07/23/2026 – Our location in the Eastern Time zone
This is Ephemeris for Thursday, July 23rd. Today the Sun will be up for 14 hours and 59 minutes, setting at 9:18, and it will rise tomorrow at 6:20. The Moon, 2 days past first quarter, will set at 1:36 tomorrow morning.
Continuing my discussion about daylight savings time: In theory time zones are supposed to be centered on longitude meridians 15º apart, starting at 0° through Greenwich Observatory in England and proceed eastward and westward. our time meridian for Standard Time (75º west longitude) runs through Philadelphia, Pennsylvania, far to the east. The central standard time meridian runs down just east of Ironwood, Michigan. Most of us in the western lower peninsula are between 85 and 86° west longitude, meaning that we are already from 40 to 45 minutes behind our time meridian in Philadelphia and Eastern Daylight Time we are an hour and 40 to 45 minutes behind our daylight time meridian which is out in the Atlantic Ocean at 60° west longitude.
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
Ephemeris: 07/22/2026 – Taking our weekly look at the whereabouts of the naked-eye planets
This is Ephemeris for Pi Approximation Day, Wednesday, July 22nd, that is 22/7ths. Today the Sun will be up for 15 hours and 1 minute, setting at 9:19, and it will rise tomorrow at 6:19. The Moon, 1 day past first quarter, will set at 1:04 tomorrow morning.
Let’s take our weekly look at the whereabouts of the naked-eye planets. By 9:45 PM tonight, nearly a half-hour after sunset, Venus will be easily spotted in the western sky. A telescope will show a tiny gibbous disc of Venus. It is now closer than the Sun, at 81.8 million miles (131.6 mil km) away from us. Over the next nearly 3 months it will be moving closer to us and becoming much larger. In the morning, Saturn and Mars will be visible, in the southeast and east respectively. The Earth is now chasing down Mars, and later this year the launch window will open to send spacecraft to the Red Planet. Mars will be closest to the Earth and opposite the sun in the sky next February.
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
Ephemeris: 07/21/2026 – The U.S. House voted to make Daylight Saving Time permanent
This is Bob Moler with Ephemeris for Tuesday, July 21st. Today the Sun will be up for 15 hours and 3 minutes, setting at 9:20, and it will rise tomorrow at 6:18. The Moon, at first quarter today, will set at 12:39 tomorrow morning.
Those who have listened to this program over the years may have been able to pick up on my feelings about daylight savings time. I’m against it. The House of Representatives has voted to make daylight savings time permanent. This kind of harkins back to the days of the oil crisis back in around 1973, that Nixon, through executive order, I believe, mandated daylight savings time year round. It didn’t last very long but, we did have a winter with daylight savings time, which in December and January makes the sunrise after 9:00 in the morning. I find this very dangerous for school kids who have to wait for school buses and go to school under nighttime conditions for several months during the year.
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
Bob Moler's Ephemeris Blog 