Archive
Ephemeris: 08/25/2026 – Thursday’s lunar eclipse – and when eclipses can occur
This is Ephemeris for Tuesday, August 25th. Today the Sun will be up for 13 hours and 34 minutes, setting at 8:31, and it will rise tomorrow at 6:58. The Moon, 3 days before full, will set at 5:06 tomorrow morning.
This Thursday’s partial lunar eclipse will occur only 15 days after the last eclipse, a nibble of a solar eclipse for us, and a total eclipse for others on August 12th. Eclipses occur in seasons of about a month long that occur at a bit less than six month intervals, so eclipses will occur a little earlier next year to this. That’s because the crossing points of the Moon’s and the Earth’s orbital planes regress slowly westward. In an eclipse season two eclipses will occur: a solar and a lunar eclipse. On rare occasions when a lunar eclipse occurs in the center of a season a partial solar eclipse can occur two weeks before and again after the lunar eclipse, but they will affect the opposite polar regions of the Earth. For Thursday night, the partial eclipse will start at 10:34 PM. Maximum eclipse occurs at 12:13 AM, and will end at 1:52 AM.
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: 08/24/2026 – Get ready for a significant partial lunar eclipse Thursday night
This is Ephemeris for Monday, August 24th. Today the Sun will be up for 13 hours and 37 minutes, setting at 8:33, and it will rise tomorrow at 6:57. The Moon, 4 days before full, will set at 3:57 tomorrow morning.
Late Thursday night and into Friday morning, clouds permitting, we will be able to see a partial eclipse of the moon. The moon will be almost totally immersed in the earth’s umbral shadow, with only a tiny sliver of the top of it visible at maximum eclipse. The partial eclipse starts at 10:34 PM EDT Thursday night (2:34 UT Friday morning the 28th). The maximum of eclipse will be at 12:13 AM (4:13 UT), and it will end at 1:52 AM (5:52 UT). So it will be nice viewing for those who can stay up late to see it. The moon will pass through the northern part of the earth’s shadow and since about 93% of the moon’s diameter will be immersed, the reddish appearance of the moon in the shadow might be apparent, and will definitely be apparent in binoculars.
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: 08/21/2026 – What are the chances of detecting another civilization in the galaxy?
This is Bob Moler with Ephemeris for Friday, August 21st. Today the Sun will be up for 13 hours and 46 minutes, setting at 8:38, and it will rise tomorrow at 6:53. The Moon, 2 days past first quarter, will set at 12:56 tomorrow morning.
At the first conference for the search for extraterrestrial intelligence held at the National Radio Astronomy Observatory in Green Bank,West Virginia, astronomer Frank Drake presented an equation on the chances for the the number of civilizations we would be capable of detecting with radio telescopes in the Galaxy. The equation had seven factors such as the average rate of star formation in the Milky Way. The fraction of those that had planets in the habitrable zone, the fraction of those in the habitable zone that actually had developed life and thae fraction of those that have intelligent life and so on. It’s called the Drake equation. And the values have only been guessed at, but there could be many.
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 Drake Equation
N: = R* x fp x ne x fl x fi x fc x L
Ephemeris: 08/20/2026 – Fermi’s Paradox
This is Ephemeris for Thursday, August 20th. Today the Sun will be up for 13 hours and 49 minutes, setting at 8:40, and it will rise tomorrow at 6:52. The Moon, 1 day past first quarter, will set at 12:11 tomorrow morning.
It is said that during lunch one day in 1950 in Los Alamos New Mexico, atomic scientist Enrico Fermi asked this question: Where is everybody? Meaning why haven’t we seen any aliens from the rest of the universe? He posited that there are many stars older than the sun by billions of years, so there could be many civilizations in the Milky Way. There is sufficient time, even traveling less than the speed of light, that a single civilization would have populated the entire Milky Way Galaxy in millions of years, a short time compared to the age of the Universe. The question is known as Fermi’s Paradox. So far the search for extraterrestrial intelligence, or SETI, has found nothing, though in the vast scheme of things, we’ve just started.
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: 08/19/2026 – Taking a weekly look at the whereabouts of the naked-eye planets
This is Ephemeris for Wednesday, August 19th. Today the Sun will be up for 13 hours and 51 minutes, setting at 8:41, and it will rise tomorrow at 6:51. The Moon, at first quarter today, will set at 11:35 this evening.
Let’s take our weekly look at the whereabouts of the naked-eye planets. By 9:15 PM tonight, a bit over a half-hour after sunset, Venus will be easily spotted in the western sky. A telescope will show a small, nearly half illuminated disk of Venus. It is now rapidly approaching earth in its orbit, at 60.9 million miles (98.1 mil km) away from us. Venus phase is turning into an ever decreasing crescent as its apparent diameter grows in telescopes. At 6 AM, Saturn, Mars and Jupiter will be visible in the south southwest, southeast and east respectively. Saturn is the brightest “star” in its part of the sky, while Mars has the competition of brighter stars, and two brighter red stars of the coming winter evenings. Jupiter is brightest of all.
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: 08/18/2026 – The Artemis III Mission
This is Ephemeris for Tuesday, August 18th. Today the Sun will be up for 13 hours and 54 minutes, setting at 8:43, and it will rise tomorrow at 6:50. The Moon, 1 day before first quarter, will set at 11:05 this evening.
Late next year or earlier 2028, NASA will launch the Artemis 3 mission to low earth orbit to test operations between the Orion spacecraft and one or both of the Human Landing Systems destined to take crews to the moon’s surface by 2030. The two landers are the SpaceX Starship HLS and Blue Origin’s Blue Moon Mark 2. Neither of the Landers will be operational, that is they may not even be pressurized, though they will need a docking port. However, it will be a test of rendezvous and docking to make sure that the vehicles can operate together. It will also be a test of the new lunar space suit. Artemis 3 will be a flight test similar to Apollo 9, except crews will not board the landers for independent flight testing.
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: 08/17/2026 – Venus has reached its greatest separation from the Sun in the evening sky
This is Bob Moler with Ephemeris for Monday, August 17th. Today the Sun will be up for 13 hours and 57 minutes, setting at 8:45, and it will rise tomorrow at 6:48. The Moon, 2 days before first quarter, will set at 10:41 this evening.
Last Saturday morning Venus reached its greatest separation from the sun in the evening sky, called the greatest eastern elongation of about 46° angle from the sun . From now until late October it will be slowly then more than more rapidly move back towards the sun, as in actuality, it moves around in its orbit of the sun towards the earth to pass between the earth and the sun October 23rd. During this period of time Venus will show a crescent phase in telescopes, becoming thinner and thinner as the days progress and also larger as it moves towards the earth. Today it’s 62.4 million miles (or 100.5 mkm) away dropping to 25.4 million miles (40.8 mkm) at its closest on October 24th.
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: 08/14/2026 – Star Party scheduled for Sleeping Bear Dunes tomorrow night
This is Ephemeris for Friday, 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 past new, will set at 9:42 this evening.
Weather permitting, the Grand Traverse Astronomical Society and the Park Rangers will host a star party at Sleeping Bear Dunes National Lakeshore, at the Dune Climb tomorrow night, Saturday August 15th, starting around 9 PM. The parking lane closest to the dune will be blocked off for telescopes. The start time is after sunset, and Venus and the crescent moon will be visible by then, but will set shortly over the dune. As it gets darker some of the brighter interstellar wonders of our Milky Way galaxy, will appear, with many star clusters and nebulae. The Rangers will leave around 11 PM. However, if it stays clear and there’s enough interest, society members will stay longer, with their telescopes. The last Sleeping Bear Dunes star party this year will be September 12th.
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: 08/13/2026 – The Milky Way seen in two cultures
This is Ephemeris for International Left-Handers Day, Thursday, August 13th. Today the Sun will be up for 14 hours and 8 minutes, setting at 8:51, and it will rise tomorrow at 6:44. The Moon, 1 day past new, will set at 9:22 this evening.
In the folk tales of many lands and cultures the Milky Way has been seen as either a stream or pathway. The term we get for it, the Milky Way, is that it is a stream of milk from the breasts of the Egyptian goddess Nut, the goddess of the sky.
The Anishinaabe native peoples of our area gave it several names: Jiibay-Miikana, The Spirit Road, or Jiibay-ziibi, River of souls, Both for the journey of souls to the afterlife. Or Binesiwi-miikana, Thunderbird’s path. This last is interesting, because in spring as the Milky Way rises from the southeast it beckons migrating birds northward, and in autumn as the Milky Way sinks to the southwest, it bids them to fly southward to warmer climes.
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: 08/12/2026 – Eclipses, meteors and planets, oh my!
This is Ephemeris for Wednesday, August 12th. Today the Sun will be up for 14 hours and 11 minutes, setting at 8:53, and it will rise tomorrow at 6:42. The Moon is new today, and won’t be visible.
Today’s a double header of astronomical events with a slight eclipse of the sun from around 12:51 to 2:04 this afternoon for Northern Michigan, and the peak of the Perseid meteor shower tonight. Also our weekly look at the naked eye planets. Venus is our brilliant evening star low in the west after sunset. This Saturday Venus will achieve it’s greatest angular separation from the sun. It will then rapidly close the distance to the sun in 2 1/2 months. It will actually be moving around and between the earth and the sun growing a larger but thinner crescent in telescopes. 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 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
More on the solar eclipse here.
More on the Perseid meteor shower here.
