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Ephemeris: 08/14/2025 – Centaur or Teapot, you decide

August 14, 2025 Comments off

This is Bob Moler with Ephemeris for Thursday, August 14th. Today the Sun will be up for 14 hours and 5 minutes, setting at 8:49, and it will rise tomorrow at 6:45. The Moon, 2 days before last quarter, will rise at 11:11 this evening.

Low in the south at 10:30 PM shines the heart of summer Milky Way. The constellation that’s seen there is Sagittarius which is supposed to be a centaur with a bow and arrow. We modern folk haven’t seen a centaur outside a Harry Potter movie, so we see its stars looking like a teapot, a short and stout little teapot like in the children’s song. It is tipped to the West with the Milky Way like steam rising from its spout, which is about to pour its tea on the southwestern horizon later tonight. Sagittarius is just begging to be explored with binoculars or a very low power telescope to see its myriad of stars, star clusters and nebulae. As fabulous as all this appears, we cannot see into the heart of the Milky Way for all the clouds of dust in the way.

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

An animated constellation of Sagittarius and Teapot asterism finder.
An animated constellation of Sagittarius and Teapot asterism finder in 4 frames for about 10:30 PM, August 14th. First the stars as they would be seen in the sky. Second, lines showing the teapot asterism with the Milky Way seen as steam rising from the spout. Then the lines drawn of the constellation in a modern rendition. And finally, the art image showing the Centaur by Stellarium. Created using Stellarium and GIMP.
Categories: Constellations, Ephemeris Program, Observing Tags: , ,

Ephemeris: 08/13/2025 – Taking our weekly look at the whereabouts of the naked-eye planets

August 13, 2025 Comments off

This is Bob Moler with Ephemeris for International Left-handers Day, Wednesday, August 13th. Today the Sun will be up for 14 hours and 7 minutes, setting at 8:51, and it will rise tomorrow at 6:44. The Moon, 3 days before last quarter, will rise at 10:47 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. The Red Planet Mars is getting so low in the western sky in evening twilight that I’ve given up on trying to spot it. 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. Mars won’t pass behind the Sun and enter the morning sky until January 9th. Saturn now rises at 10:23 PM in the east. In a telescope Saturn sports a very thin ring, less than 4° from being edge on. By 5:30 AM Saturn will be high in the south, when our winter pal Orion will be rising. Venus and Jupiter will appear very close. Venus is by far the brighter of the two.

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

Mars and Spica this evening in the western sky an hour after sunset
Mars and Spica this evening in the western sky an hour after sunset here (9:51 PM), August 13, 2025. With the smoke from the Canadian wild files, I doubt any stars or planets could be seen near the horizon. Created using Stellarium.
Saturn, Jupiter and Venus with some bright winter stars at 5:45 AM tomorrow morning
Saturn, Jupiter and Venus with some bright winter stars at 5:45 AM tomorrow morning, August 14th, 2025, looking from east-northeast to southwest. Created using Stellarium.
The Moon tomorrow morning, August 14, 2025. A view visible in small telescopes showing an image with and without selected features labeled. Feature labels are centered. Created using Stellarium, LibreOffice Draw, and GIMP.
Telescopic Saturn, Jupiter and Venus 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 morning of the August 14th 2025, Saturn will be 19.0″ in diameter, but its rings, even being nearly edge on, should show up brighter than seen here., and extend to 44.2″. They are tilted 3.1° from being edge on. Jupiter will be 33.3″ in diameter. Venus’ apparent diameter will be 13.3″, and be 79.4% illuminated. The ” 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 August 13, 2025. The night ends on the left with sunrise on the 14th. 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, August 13th and 14th, 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: 08/12/2025 – A brief shot at viewing the Perseid meteors under darkened, but not dark skies

August 12, 2025 Comments off

This is Ephemeris for Tuesday, August 12th. Today the Sun will be up for 14 hours and 10 minutes, setting at 8:52, and it will rise tomorrow at 6:43. The Moon, 3 days past full, will rise at 10:26 this evening.

Tonight we get a second chance to see some of the Perseid meteor shower. As I said yesterday, the Moon is going to interfere with this year’s display. But, there is a small interval during twilight this evening, before the moon rises, where the sky could be dark enough to see more than a few Perseids. For nearly half an hour after 10 PM, it might be dark enough to see the Perseids under reasonably dark skies. The radiant where the meteors appear to come from will be low in the north northeast, about 17° above the horizon which means the expected number of meteors one would see in a half hour would be about 15 and with a not quite dark skies probably be a little less than that. But it is a chance to see the Perseids this 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

The dome of the sky at 10 PM this evening, August 12th 2025
The dome of the sky at 10 PM this evening, August 12th 2025. This is near the end of nautical twilight, a time when we amateur astronomers begin to view the brighter deep sky objects such as star clusters and nebulae. So it should be dark enough to see all but the faintest Perseid meteors before the Moon rises. The radiant PerR is low in the north northeast at that time, but the meteors will be seen all over the sky. Their tracks can be traced back to the radiant. Created using my LookingUp app.

Categories: Ephemeris Program, Meteor Shower, Observing Tags:

Ephemeris: 08/11/2025 – The best times to see the Perseid meteor shower

August 11, 2025 Comments off

This is Ephemeris for Monday, August 11th. Today the Sun will be up for 14 hours and 13 minutes, setting at 8:54, and it will rise tomorrow at 6:42. The Moon, 2 days past full, will rise at 10:06 this evening.

Tonight’s most interesting astronomical events will occur tomorrow morning. The Perseid meteor shower will reach its peak tomorrow afternoon, so tomorrow morning and Wednesday morning will be about the best times to see the meteors, except that the bright Moon is going to interfere. So only the brightest meteors will be visible. Bonus: in morning twilight tomorrow the planets Venus and Jupiter will be in conjunction, meaning they’ll be at their closest appearance to each other by a little bit less than twice the width of the Moon apart. Early risers may have been noticing that Venus and Jupiter will have been slowly approaching each other, with Jupiter below and left of Venus. Tomorrow morning, Jupiter will pass just above Venus.

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

My best Perseid photo. From the 1970's.
My best Perseid photo. From the 1970’s. The other streaks are stars due to the earth’s rotation during the time exposure of the stationary camera. The camera was aimed near the radiant, where the meteoric streaks are shorter because they are coming almost right at us. This one would be visible on the brightest moonlit night.

Categories: Conjunction, Ephemeris Program, Meteor Shower, Naked-eye planets, Observing Tags: , ,

Ephemeris: 08/08/2025 – Mercury’s strange rotation

August 8, 2025 Comments off

This is Ephemeris for Friday, August 8th. Today the Sun will be up for 14 hours and 21 minutes, setting at 8:58, and it will rise tomorrow at 6:38. The Moon, 1 day before full, will set at 6:42 tomorrow morning.

The planet Mercury is the closest planet to the Sun, and for a long time was thought to have synchronous rotation. That is it rotated in the same 88 days it took to orbit the Sun. However, in 1965 using radar from the Arecibo Observatory in Puerto Rico, astronomers learned that the rotation was exactly 2/3 of that 88 days. An interesting relationship of the sidereal rotation of 59 days against the stars, 2/3 of the Mercury’s year. Earth’s solar day, noon to noon is 3 minutes 56 seconds longer than the sidereal day. Mercury’s solar day turns out to be exactly 2 Mercurian years long.

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

Mercury's 2/3 of a year rotation. 59 days vs 88 day year
Mercury’s 2/3 of a year rotation of 59 days vs 88 day year. Mercury rotates 3 times while it orbits the Sun twice, making its solar day equal two Mercurian years. Each Mercury position is at 90° or ¼ of a rotation. The spots on the Mercury symbol show the rotation of a fixed spot on the planet, blue for the first year, red for the second. Spots 7 and 15 actually overlay 1. Credit: https://solarviews.com/eng/mercury.htm.
Categories: Concepts, Ephemeris Program, Mercury

Ephemeris: 08/07/2025 – Does the Moon rotate?

August 7, 2025 Comments off

This is Ephemeris for Thursday, August 7th. Today the Sun will be up for 14 hours and 23 minutes, setting at 9:00, and it will rise tomorrow at 6:37. The Moon, 2 days before full, will set at 5:26 tomorrow morning.

The moon exhibits the same face to the Earth throughout the month. That doesn’t mean the Moon doesn’t rotate. It means that the moon rotates in the same time it takes to orbit the Earth. This is called synchronous rotation. It is also known as tidal locking, caused by the difference in the gravitational attraction across the body of the Moon from the near side to the far side. The same thing happens with the Earth and is best seen by the ocean tides on the part of the Earth facing and away from the Moon. The reason the Earth is not tidally locked is that it is much more massive. But the Moon is slowing down the Earth’s rotation. But by doing that, it is moving further away, so it will never totally lock the Earth’s rotation with it.

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 Moon's rotation through the lunar month
“I only have eyes for you.” Is what the Moon is singing, as it orbits the Earth in synchronous rotation in this animation. Credit: NASA/JPL-Caltech.
Categories: Concepts, Ephemeris Program, The Moon

Ephemeris: 08/06/2025 – Taking our weekly look at the whereabouts of the naked-eye planets

August 6, 2025 Comments off

This is Ephemeris for Wednesday, August 6th. Today the Sun will be up for 14 hours and 26 minutes, setting at 9:01, and it will rise tomorrow at 6:36. The Moon, 3 days before full, will set at 4:13 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. The Red Planet Mars, May be seen very low in the western sky at 10 PM. Mars is moving toward Spica, a bit higher in the west-southwest. Mars will pass Spica on September 12th. By then they will be too low in the sky to be seen in twilight. Mars will leave the evening sky on January 9th. Saturn now rises at 10:50 PM in the east. In a telescope Saturn sports a very thin ring, less than 4° from being edge on. By 5:30 AM Saturn will be high in the south, when our winter pal Orion will be rising. Venus and Jupiter will appear very close. Venus is by far the brighter of the two. Their paths will cross on the morning of the 12th, where they will appear less than 2 moon-widths apart.

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

Mars and Spica this evening in the western sky near 10 PM, August 6, 2025
Mars and Spica this evening in the western sky near 10 PM, August 6, 2025. Created using Stellarium.
The Moon tonight, August 6, 2025. A view visible in small telescopes showing an image with and without selected features labeled. Feature labels are centered. Created using Stellarium, LibreOffice Draw, and GIMP.
Saturn, Venus and Jupiter with some bright winter stars at 5:30 AM tomorrow morning, August 7th, 2025, looking from east-northeast to south.
Saturn, Venus and Jupiter with some bright winter stars at 5:30 AM tomorrow morning, August 7th, 2025, looking from east-northeast to south. Created using Stellarium.
Telescopic Saturn, Venus and Jupiter (north up) as they would be seen in a small telescope with the same magnification.
Telescopic Saturn, Venus and Jupiter (north up) as they would be seen in a small telescope with the same magnification. On the evening of August 6, 2025, Mars will be 4.4″ in diameter, too small to be shown here. My lower size limit is 10″. On the morning of the 7th, Saturn will be 18.8″ in diameter, but its rings, even being nearly edge on, should show up brighter than seen here., and extend to 43.8″. They are tilted 3.3° from being edge on. Venus’ apparent diameter will be 13.8″, and be 77.2% illuminated. Jupiter will be 32.9″ in diameter, though its satellites may not be visible in the morning twilight. The ” 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, starting with sunset on the right on August 6, 2025. The night ends on the left with sunrise on the 7th.
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on August 6, 2025. The night ends on the left with sunrise on the 7th. 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, August 6th and 7th, 2025.
This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, August 6th and 7th, 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: 08/05/2025 – Why space faring nations are fixated on the Moon’s South Pole

August 5, 2025 Comments off

This is Ephemeris for Tuesday, August 5th. Today the Sun will be up for 14 hours and 28 minutes, setting at 9:02, and it will rise tomorrow at 6:35. The Moon, halfway from first quarter to full, will set at 3:06 tomorrow morning.

After more than 50 years since the Apollo landings on the Moon, space faring nations are beginning to be interested in one particular place on the Moon for further exploration. That is the lunar South Pole. The reason is the discovery of something more valuable than gold. That there may be water hidden in permanently shadowed craters there. The moon’s North Pole is not as rugged, so there’s probably not as much water there. Water can exist on the Moon but only in its frozen form, ice in permanently shadowed craters. The Moon’s axial tilt is only about 1 1/2° compared to the Earth’s 23 1/2°. The water molecule is the second most abundant in the universe after diatomic hydrogen, but normally cannot exist this close to the Sun.

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

Map of water at the Moon's poles
The Moon’s south pole area on the left and north pole on the right. The cyan color shows shadowed areas where ice is located. Credit NASA
South pole ice
The south pole of the Moon where the presence of water ice is detected by the absorption of neutrons by the hydrogen atoms in the ice. Credit NASA/GSFC/SVS/Roscosmos.
Categories: Ephemeris Program, Space exploration, The Moon Tags:

Ephemeris: 08/04/2025 – Mars’ twin

August 4, 2025 Comments off

This is Bob Moler with Ephemeris for Monday, August 4th. Today the Sun will be up for 14 hours and 31 minutes, setting at 9:04, and it will rise tomorrow at 6:33. The Moon, 3 days past first quarter, will set at 2:10 tomorrow morning.

Low in the south as it gets dark is the red giant star Antares. It lies at the heart of Scorpius the scorpion. Its name means Rival of Mars, because it has the same hue as the red planet.  In Mars case the color comes from iron oxide, rust.  In Antares case it has a cool surface temperature, relatively speaking, of 7,000 degrees Fahrenheit (3,660 K).  As a red giant star Antares is near the end of its life, though compared to the Sun it is young – possibly 12 million years old.  At that age the Sun was just getting started.  Antares, with around 13 to 16 times the Sun’s mass, has already run out of fusible hydrogen in its core and has bloated out to double Mars’ orbit in size.  Antares is 550 light years away and has a companion star in its system that looks greenish in contrast to Antares red.  But, when Antares A, the red giant’s light is blocked, the companion looks bluish.

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

Antares finder: The southern sky at 10 PM tonight and 9 days from now, when the Moon is out of the way.
Antares finder: The southern sky at 10 PM tonight and 9 days from now, when the Moon is out of the way. The Teapot pattern of stars on the left of the image is Sagittarius. Created using Stellarium and GIMP.
Antares and companion.
Antares and companion. Credit to John Hothersall, posted on stargazerslounge.com, July 5, 2016 with the caption: “This is my best image of the two as the colour of the companion is obvious as seeing was good. Orbital period 1200-2600 years and separation 503 AU.”
Categories: Ephemeris Program, Observing, Stars Tags:

Ephemeris: 08/01/2025 – Preview August skies

August 1, 2025 Comments off

This is Bob Moler with Ephemeris for Friday, August 1st. Today the Sun will be up for 14 hours and 38 minutes, setting at 9:08, and it will rise tomorrow at 6:30. The Moon, at first quarter today, will set at 12:21 tomorrow morning.

Let’s look ahead at the month of August in the skies. Daylight hours will decrease from 14 hours and 38 minutes today to 13 hours 16 minutes on the 31st. The altitude of the Sun at local noon, that is, degrees of angle above the horizon, will decrease from 63 degrees today to just over 53 degrees on the 31st. Straits area listeners can subtract one more degree from those angles, but their daylight hours will be a few minutes longer. Local noon, when the Sun is due south, is about 1:43 p.m. The Perseid meteor shower will reach its peak on the afternoon of the12th. But, the waning gibbous Moon will interfere with all but the brightest meteors. So the best time to see them is after moonset in the morning for the next several days.

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

Star Chart for August 2025 (10 p.m. EDT, August 15, 2025)
Star Chart for August 2025 (10 p.m. EDT, August 15, 2025). Click or tap on the image to enlarge it. Created with my LookingUp program.

The planets and stars are plotted for the 15th at 10 pm EDT in the evening and 4:30 am on the 16th. 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.

Note the chart times are for the mid-month. For each week before then, add ½ hour (28 minutes if you’re picky). For each week after then, subtract ½ hour. The planet positions are updated each Wednesday on this blog. See them for planet positions on dates other than the mid-month.

August Morning Star Chart

Star Chart for August 2025 mornings, (4:30 a.m. EDT, August 16, 2025).
Star Chart for August 2025 mornings, (4:30 a.m. EDT, August 16, 2025). Click or tap on the image to enlarge it. Created with 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, and
  • Extend like a spike to Spica.
  • The Summer Triangle is in red.
  • PerR is the radiant of the Perseid meteor shower (Peaks on the afternoon of the 12th)

Twilight Limits, Nautical and Astronomical

      EDT        
  Morning Twilight Evening Twilight Dark Night Moon
Date Astro. Nautical Nautical Astro. Start End Illum.
2025-08-01 4h27m 5h16m 22h26m 23h15m – 4h27m 0.57
2025-08-02 4h29m 5h17m 22h25m 23h13m 0h22m 4h29m 0.66
2025-08-03 4h31m 5h19m 22h23m 23h10m 0h50m 4h31m 0.75
2025-08-04 4h33m 5h20m 22h21m 23h08m 1h25m 4h33m 0.83
2025-08-05 4h35m 5h22m 22h20m 23h06m 2h10m 4h35m 0.90
2025-08-06 4h37m 5h23m 22h18m 23h04m 3h07m 4h37m 0.95
2025-08-07 4h39m 5h24m 22h16m 23h02m 4h14m 4h39m 0.99
2025-08-08 4h41m 5h26m 22h15m 23h00m – – 1.00
2025-08-09 4h43m 5h27m 22h13m 22h58m – – 0.99
2025-08-10 4h44m 5h29m 22h11m 22h55m – – 0.96
2025-08-11 4h46m 5h30m 22h09m 22h53m – – 0.90
2025-08-12 4h48m 5h32m 22h07m 22h51m – – 0.82
2025-08-13 4h50m 5h33m 22h05m 22h49m – – 0.72
2025-08-14 4h52m 5h35m 22h04m 22h47m 22h47m 23h11m 0.62
2025-08-15 4h54m 5h36m 22h02m 22h44m 22h44m 23h41m 0.50
2025-08-16 4h55m 5h38m 22h00m 22h42m 22h42m – 0.39
2025-08-17 4h57m 5h39m 21h58m 22h40m 22h40m 0h20m 0.28
2025-08-18 4h59m 5h41m 21h56m 22h38m 22h38m 1h10m 0.18
2025-08-19 5h01m 5h42m 21h54m 22h36m 22h36m 2h13m 0.11
2025-08-20 5h03m 5h44m 21h52m 22h33m 22h33m 3h25m 0.05
2025-08-21 5h04m 5h45m 21h50m 22h31m 22h31m 4h42m 0.01
2025-08-22 5h06m 5h47m 21h48m 22h29m 22h29m 5h06m 0.00
2025-08-23 5h08m 5h48m 21h46m 22h27m 22h27m 5h08m 0.01
2025-08-24 5h09m 5h50m 21h44m 22h24m 22h24m 5h09m 0.04
2025-08-25 5h11m 5h51m 21h42m 22h22m 22h22m 5h11m 0.09
2025-08-26 5h13m 5h52m 21h40m 22h20m 22h20m 5h13m 0.15
2025-08-27 5h15m 5h54m 21h38m 22h18m 22h18m 5h15m 0.23
2025-08-28 5h16m 5h55m 21h36m 22h15m 22h24m 5h16m 0.31
2025-08-29 5h18m 5h57m 21h34m 22h13m 22h49m 5h18m 0.40
2025-08-30 5h19m 5h58m 21h32m 22h11m 23h21m 5h19m 0.50
2025-08-31 5h21m 5h59m 21h30m 22h09m – 5h21m 0.59

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  Fr            Venus: 38° W
     1  Fr   8:41 AM  First Quarter
     1  Fr   4:37 PM  Moon Apogee: 404200 km
     3  Su   9:40 PM  Moon-Antares: 0.6° N
     5  Tu   9:37 AM  Moon South Dec.: 28.5° S
     9  Sa   3:55 AM  Full Moon
    11  Mo  10:53 AM  Moon Ascending Node
    12  Tu   2:53 AM  Venus-Jupiter: 0.9° N
    12  Tu  11:05 AM  Moon-Saturn: 4.1° S
    12  Tu   3:47 PM  Perseid Shower: ZHR = 90
    14  Th   2:01 PM  Moon Perigee: 369300 km
    16  Sa   1:12 AM  Last Quarter
    16  Sa  12:09 PM  Moon-Pleiades: 0.9° S
    18  Mo  11:59 AM  Moon North Dec.: 28.6° N
    19  Tu  12:58 AM  Mercury-Beehive: 2.6° S
    19  Tu   5:59 AM  Mercury Elongation: 18.6° W
    19  Tu   5:05 PM  Moon-Jupiter: 4.9° S
    20  We   6:51 AM  Moon-Venus: 5° S
    20  We   8:07 AM  Moon-Pollux: 2.5° N
    21  Th   7:09 AM  Moon-Beehive: 2.1° S
    23  Sa   2:06 AM  New Moon
    24  Su  11:41 AM  Moon Descending Node
    26  Tu  12:41 PM  Moon-Mars: 3° N
    27  We   9:57 AM  Moon-Spica: 1.2° N
    29  Fr  11:34 AM  Moon Apogee: 404600 km
    31  Su   2:25 AM  First Quarter
    31  Su   5:55 AM  Moon-Antares: 0.7° N
    31  Su   1:59 PM  Venus-Beehive: 1.5° S
Sep  1  Mo            Venus: 31.2° W

Planetary 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.

Sun and Moon Rising and Setting Events

LU                  Ephemeris of Sky Events for Interlochen/TC
August, 2025    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Fri  1| 06:29a  09:08p  14:38 | 10:23p  05:13a |F Qtr Set  12:21a   54%|
|Sat  2| 06:30a  09:06p  14:36 | 10:21p  05:15a |      Set  12:49a   64%|
+------+-----------------------+----------------+-----------------------+
|Sun  3| 06:31a  09:05p  14:33 | 10:20p  05:16a |      Set  01:24a   73%|
|Mon  4| 06:32a  09:04p  14:31 | 10:18p  05:18a |      Set  02:10a   81%|
|Tue  5| 06:33a  09:02p  14:28 | 10:16p  05:19a |      Set  03:06a   88%|
|Wed  6| 06:35a  09:01p  14:26 | 10:14p  05:21a |      Set  04:13a   94%|
|Thu  7| 06:36a  09:00p  14:23 | 10:13p  05:22a |      Set  05:26a   98%|
|Fri  8| 06:37a  08:58p  14:21 | 10:11p  05:24a |      Set  06:42a  100%|
|Sat  9| 06:38a  08:57p  14:18 | 10:09p  05:25a |Full  Rise 09:26p   99%|
+------+-----------------------+----------------+-----------------------+
|Sun 10| 06:39a  08:55p  14:15 | 10:07p  05:27a |      Rise 09:47p   97%|
|Mon 11| 06:40a  08:54p  14:13 | 10:05p  05:28a |      Rise 10:06p   91%|
|Tue 12| 06:42a  08:52p  14:10 | 10:04p  05:30a |      Rise 10:26p   84%|
|Wed 13| 06:43a  08:51p  14:07 | 10:02p  05:31a |      Rise 10:47p   75%|
|Thu 14| 06:44a  08:49p  14:05 | 10:00p  05:33a |      Rise 11:11p   64%|
|Fri 15| 06:45a  08:48p  14:02 | 09:58p  05:34a |      Rise 11:41p   53%|
|Sat 16| 06:46a  08:46p  13:59 | 09:56p  05:36a |L Qtr Rise 12:19a   41%|
+------+-----------------------+----------------+-----------------------+
|Sun 17| 06:47a  08:44p  13:56 | 09:54p  05:37a |      Rise 01:10a   30%|
|Mon 18| 06:49a  08:43p  13:54 | 09:52p  05:39a |      Rise 02:12a   20%|
|Tue 19| 06:50a  08:41p  13:51 | 09:50p  05:40a |      Rise 03:25a   12%|
|Wed 20| 06:51a  08:39p  13:48 | 09:48p  05:42a |      Rise 04:41a    6%|
|Thu 21| 06:52a  08:38p  13:45 | 09:46p  05:43a |      Rise 05:57a    2%|
|Fri 22| 06:53a  08:36p  13:42 | 09:44p  05:45a |      Rise 07:10a    0%|
|Sat 23| 06:55a  08:34p  13:39 | 09:42p  05:46a |New   Set  08:54p    1%|
+------+-----------------------+----------------+-----------------------+
|Sun 24| 06:56a  08:33p  13:36 | 09:41p  05:47a |      Set  09:11p    3%|
|Mon 25| 06:57a  08:31p  13:33 | 09:39p  05:49a |      Set  09:27p    8%|
|Tue 26| 06:58a  08:29p  13:31 | 09:37p  05:50a |      Set  09:44p   14%|
|Wed 27| 06:59a  08:27p  13:28 | 09:35p  05:52a |      Set  10:02p   21%|
|Thu 28| 07:00a  08:26p  13:25 | 09:33p  05:53a |      Set  10:23p   29%|
|Fri 29| 07:02a  08:24p  13:22 | 09:31p  05:55a |      Set  10:48p   38%|
|Sat 30| 07:03a  08:22p  13:19 | 09:29p  05:56a |      Set  11:20p   47%|
+------+-----------------------+----------------+-----------------------+
|Sun 31| 07:04a  08:20p  13:16 | 09:27p  05:57a |F Qtr Set  12:01a   57%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise

Generated using my LookingUp for DOS app.

Categories: Ephemeris Program, Month preview Tags: