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Ephemeris: 09/02/2026 – Taking our weekly look at the whereabouts of the naked-eye planets

September 2, 2026 Comments off

This is Ephemeris for Wednesday, September 2nd. Today the Sun will be up for 13 hours and 11 minutes, setting at 8:17, and it will rise tomorrow at 7:07. The Moon, 2 days before last quarter, will rise at 10:33 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. By 8:45 PM tonight, a nearly a half-hour after sunset, Venus will be spotted low in the west southwestern sky. Though at a 44º angle from the sun, it’ll only be 6º above the horizon then. A telescope will show a small crescent disk of the planet. It is now rapidly approaching earth in its orbit, at 50.8 million miles (81.8 mil km) away from us. Venus is becoming an ever decreasing crescent as its apparent diameter grows in telescopes. At 6 AM, Saturn will be alone in the southwest, while Mars and Jupiter will be in the east. Jupiter is brightest and lowest while Mars has the competition of brighter stars in Gemini.

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

Venus appears low in the west southwestern sky at 8:45 PM tonight
Venus appears low in the west southwestern sky at 8:45 PM tonight, September 2, 2026. Created using Stellarium.
Saturn, Mars, Jupiter and the Moon will be seen at 6:00 AM tomorrow morning September 3, 2026.
Saturn, Mars, Jupiter and the Moon will be seen at 6:00 AM tomorrow morning September 3, 2026. Mars, in Gemini, is entering the part of the sky with bright stars, the winter sky. So it won’t stand out until it gets much closer to the Earth. Jupiter is brighter than all the rest. Created using Stellarium.
Moon a day before last quarter at 6 AM tomorrow morning, September 3, 2026. A view visible in small telescopes showing an image with and without selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
Telescopic Venus at 8:45 PM tonight, September 2, 2026, and Saturn and Jupiter at 6:00 AM.
Telescopic Venus at 8:45 PM tonight, September 2, 2026, and Saturn and Jupiter at 6:00 AM on the 3rd (north up), as they would be seen in a small telescope with the same magnification. Venus’ apparent diameter will be 31.0″, and be 37.5% illuminated. Saturn will be 19.4″ in diameter, and its rings extend to 45.1″, and are tilted 8.6º to our view. Jupiter will be 31.9″ in diameter. Mars, not shown, will appear 5.1″ in diameter. The (”) symbol means seconds of arc, or 1/3600th of a degree. Created using Cartes du Ciel (Sky Charts), LibreOffice Draw and GIMP.
Telescopic Venus at 8:45 PM tonight, September 2, 2026, and Saturn and Jupiter at 6:00 AM.
The naked-eye planets at sunset and sunrise on a single night, starting with sunset on the right on September 2, 2026. The night ends on the left with sunrise on the 3rd. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
The naked-eye planets, from Mercury to Saturn, in a low angle perspective view of the solar system from above and a bit beyond Saturn’s orbit for today, September 2, 2026.
The naked-eye planets, from Mercury to Saturn, in a low angle perspective view of the solar system from above and a bit beyond Saturn’s orbit for today, September 2, 2026. Created using my LookingUp app, text and arrows created using LibreOffice Draw and produced a unified image using GIMP.
Categories: Ephemeris Program, Naked-eye planets, Observing Tags: , , , , ,

Ephemeris: 09/01/2026 – Previewing September skies

September 1, 2026 Comments off

This is Bob Moler with Ephemeris for Tuesday, September 1st. Today the Sun will be up for 13 hours and 14 minutes, setting at 8:19, and it will rise tomorrow at 7:06. The Moon, 3 days before last quarter, will rise at 10:00 this evening.

Let’s look at the skies for the month of September, a transition month between summer and autumn. 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 14 minutes today to 11 hours 45 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. The season of summer is getting short, so enjoy it while you can. Summer ends and autumn begins at 8:06 p.m. with the autumnal equinox on September 22nd. The Harvest Moon will occur on the 26th, being the closest 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

September Evening Star Chart

Star Chart for September 2026 (10 PM EDT, September 15).
Star Chart for September 2026 (10 PM EDT, September 15). 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 16)
Star Chart for September 2025 (6 am EDT, September 16). Click on the image to enlarge it. Created using my LookingUp program.

Twilight Limits, Nautical and Astronomical

      EDT        
  Morning Twilight Evening Twilight Dark Night Moon
Date Astro. Nautical Nautical Astro. Start End Illum.
2026-09-01 5h22m 6h00m 21h29m 22h07m – – 73%
2026-09-02 5h24m 6h02m 21h27m 22h05m 22h05m 22h33m 63%
2026-09-03 5h25m 6h03m 21h25m 22h03m 22h03m 23h16m 52%
2026-09-04 5h27m 6h05m 21h23m 22h00m 22h00m – 40%
2026-09-05 5h28m 6h06m 21h21m 21h58m 21h58m 0h11m 29%
2026-09-06 5h30m 6h07m 21h19m 21h56m 21h56m 1h20m 19%
2026-09-07 5h32m 6h09m 21h17m 21h54m 21h54m 2h37m 11%
2026-09-08 5h33m 6h10m 21h15m 21h51m 21h51m 3h58m 5%
2026-09-09 5h35m 6h11m 21h13m 21h49m 21h49m 5h18m 1%
2026-09-10 5h36m 6h13m 21h11m 21h47m 21h47m 5h36m 0%
2026-09-11 5h38m 6h14m 21h09m 21h45m 21h45m 5h38m 1%
2026-09-12 5h39m 6h15m 21h07m 21h43m 21h43m 5h39m 5%
2026-09-13 5h40m 6h17m 21h05m 21h41m 21h41m 5h40m 11%
2026-09-14 5h42m 6h18m 21h03m 21h38m 21h38m 5h42m 18%
2026-09-15 5h43m 6h19m 21h01m 21h36m 21h36m 5h43m 26%
2026-09-16 5h45m 6h20m 20h59m 21h34m 22h08m 5h45m 35%
2026-09-17 5h46m 6h22m 20h57m 21h32m 22h50m 5h46m 44%
2026-09-18 5h48m 6h23m 20h55m 21h30m 23h40m 5h48m 53%
2026-09-19 5h49m 6h24m 20h53m 21h28m – 5h49m 63%
2026-09-20 5h50m 6h25m 20h51m 21h26m 0h39m 5h50m 72%
2026-09-21 5h52m 6h27m 20h49m 21h24m 1h43m 5h52m 80%
2026-09-22 5h53m 6h28m 20h47m 21h22m 2h50m 5h53m 87%
2026-09-23 5h54m 6h29m 20h45m 21h20m 3h59m 5h54m 93%
2026-09-24 5h56m 6h31m 20h43m 21h18m 5h08m 5h56m 97%
2026-09-25 5h57m 6h32m 20h41m 21h16m – – 100%
2026-09-26 5h58m 6h33m 20h39m 21h13m – – 100%
2026-09-27 6h00m 6h34m 20h37m 21h11m – – 97%
2026-09-28 6h01m 6h35m 20h35m 21h09m – – 92%
2026-09-29 6h02m 6h37m 20h33m 21h08m – – 85%
2026-09-30 6h04m 6h38m 20h31m 21h06m 21h06m 21h15m 76%

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

Date         Time     Event
Sep  1  Tu            Venus: 44.6° E
     1  Tu   9:27 AM  Venus-Spica: 1.4° S
     3  Th   8:03 AM  Moon-Pleiades: 1.2° S
     4  Fr   3:51 AM  Last Quarter
     5  Sa   2:12 AM  Moon North Dec.: 28.1° N
     6  Su   2:24 PM  Moon-Mars: 3° S
     6  Su   4:26 PM  Moon Perigee: 368300 km
     8  Tu  12:43 AM  Moon-Beehive: 0.5° S
     8  Tu   2:13 PM  Moon-Jupiter: 0.8° S
     9  We   3:17 PM  Moon Descending Node
    10  Th  11:27 PM  New Moon
    13  Su   4:53 PM  Moon-Spica: 2.6° N
    14  Mo   7:10 AM  Moon-Venus: 0.6° S
    16  We   9:42 PM  Mars-Pollux: 5.9° S
    17  Th   8:18 AM  Moon-Antares: 0.6° N
    18  Fr   2:54 PM  Moon South Dec.: 28.1° S
    18  Fr   4:44 PM  First Quarter
    18  Fr  11:00 PM  Moon Apogee: 404200 km
    22  Tu   8:06 PM  Autumnal Equinox
    23  We  10:40 PM  Moon Ascending Node
    25  Fr   8:13 PM  Neptune Opposition
    25  Fr   9:49 PM  Mercury-Spica: 0.9° N
    26  Sa  12:49 PM  Full Moon (Harvest Moon)
    30  We   1:39 PM  Moon-Pleiades: 1.1° S

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.

Categories: Ephemeris Program, Month preview, Observing Tags: