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Ephemeris: 03/13/2026 – Precession of the equinoxes

March 13, 2026 Comments off

This is Ephemeris for Friday, March 13th. Today the Sun will be up for 11 hours and 47 minutes, setting at 7:46, and it will rise tomorrow at 7:56. The Moon, 2 days past last quarter, will rise at 6:01 tomorrow morning.

Yesterday I talked about the fact that the constellation of Cancer the crab is no longer the northernmost constellation of the zodiac, where the Sun is positioned on the first day of summer. There’s been a slow change in the position of the earth’s axis, in that it wobbles slowly in a period of nearly 26,000 years. The inclination of the Earth’s axis to its orbit is around 23 1/2 degrees, and the gravitational pull of the Moon and the Sun on the Earth’s equatorial bulge, wants to straighten it up. But because the Earth is spinning, it wobbles instead, slowly sliding the actual zodiacal constellations eastward about one constellation in 2,150 years. So the actual constellations are off one constellation from the astrological signs.

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; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.

Addendum

An animation of the precession of the equinoxes.
An animation of the precession of the equinoxes. The blue horizontal line is the celestial equator. The orange line is the ecliptic, the apparent annual path of the Sun against the stars. Where the two lines cross is the vernal equinox where the Sun is on the first day of spring, which on our calendar is trending to be March 20th. The slippage of the stars eastward (to the left) along the ecliptic is about the apparent width of the Sun or Moon, or half a degree, in 36 years. We’re looking at two different years 150 CE, the time of Ptolemy, and our time. To tell which is which, the one from our time has Saturn at the lower right. Jupiter happens to be in both of them, but it’s obviously been around lots of times between then and now. Created using Stellarium and GIMP.
The force causing precession
The Moon and Sun’s gravitational force act on the Earth’s equatorial bulge attempting to cause the earth to straighten up and fly right. Because the Earth is spinning, it acts like a gyroscope and the torque to straighten it up causes it to be applied 90 degrees away in the direction of the rotation causing the procession. Credit: Open Course: Astronomy.
Precession circle
The path of the north pole of the sky (celestial sphere) over time. The celestial north pole is still approaching Polaris. In the past the Big Dipper was closer to the north pole of the sky than it is now. Polaris will be it closest to the north pole around the year 2110. Source: taichifuture.com/cosmology.html.
Categories: Concepts, Zodiac Tags:

Ephemeris: 03/12/2026 – Cancer the crab used to welcome summer

March 12, 2026 Comments off

This is Ephemeris for Thursday, March 12th. Today the Sun will be up for 11 hours and 44 minutes, setting at 7:45, and it will rise tomorrow at 7:58. The Moon, 1 day past last quarter, will rise at 5:25 tomorrow morning.

There’s a line on some globes and maps at approximately 23 1/2° north latitude called the Tropic of Cancer. It’s related to the constellation Cancer the crab. However, Cancer no longer fits that role that it was named to a couple of thousand years ago, when the sun entered the constellation of Cancer on the first day of summer. That’s the latitude on the Earth where the Sun was directly overhead on the first day of summer. Now that an honor goes to Gemini. The way we draw the figure of that constellation, the Sun is right near Castor’s big toe on the first day of summer. But I don’t think they’re going to change the name anytime soon. The reason for the change is that the Earth’s axis slowly wobbles like a top or gyroscope as they slow down. The effect is called precession.

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; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Comparison of the position of the Sun against the constellations on the summer solstice from 150 CE to now due to the precession of the equinoxes.
Comparison of the position of the Sun against the constellations on the summer solstice from 150 CE to now due to the precession of the equinoxes. The reason I chose 150 CE, is that it was the approximate date of Ptolemy’s Almagast, the standard work on astronomy until Copernicus in the 16th century or later. Created using Stellarium, LibreOffice Draw and GIMP.
How the tropics of Cancer and Capricorn line up with the Sun on the solstices.
How the tropics of Cancer and Capricorn line up with the Sun on the solstices. From an animation in Wikipedia, in the Public Domain.

The Greek letter epsilon in the image above represents the tilt of the Earth’s axis of around 23.5°. Astronomers call it the obliquity of the ecliptic, the angle between the ecliptic and the celestial equator as seen in the illustration below.

An animation of the precession of the equinoxes.
An animation of the precession of the equinoxes. The blue horizontal line is the celestial equator. The orange line is the ecliptic, the apparent annual path of the Sun against the stars. Where the two lines cross is the vernal equinox where the Sun is on the first day of spring, which on our calendar is trending to be March 20th. The slippage of the stars eastward (to the left) along the ecliptic is about the apparent width of the Sun or Moon, or half a degree, in 36 years. We’re looking at two different years 150 CE, the time of Ptolemy, and our time. To tell which is which, the one from our time has Saturn at the lower right. Jupiter happens to be in both of them, but it’s obviously been around lots of times between then and now. Created using Stellarium and GIMP.
Precesion animation
The 25,700-year cycle of precession as seen from near the Earth. The current North Pole star is Polaris (top). In about 8,000 years it will be the bright star Deneb (left), and in about 12,000 years, Vega (left center). The Earth’s rotation is not depicted to scale – in this span of time, it would actually rotate over 9 million times. Credit image Tfrooo, caption Wikipedia.
Categories: Concepts, Constellations, Ephemeris Program, Seasons, Uncategorized Tags:

Ephemeris: 03/11/2026 – Taking our weekly look at the whereabouts of the naked-eye planets

March 11, 2026 Comments off

This is Ephemeris for Wednesday, March 11th. Today the Sun will be up for 11 hours and 41 minutes, setting at 7:43, and it will rise tomorrow at 8:00. The Moon, at last quarter today, will rise at 4:42 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. At 8:15 PM or about a half hour after sunset, Venus may be seen very low in the West. A very low western horizon will be necessary to spot it, like from the shore of Lake Michigan. Saturn is no longer visible, being too close to the direction of the Sun. Jupiter is the brilliant star-like object more than halfway up in the southern sky. It’s the brightest star-like object in the sky. The planet and its moons are a treat for binoculars or a telescope. Jupiter’s four brightest, so-called Galilean Moons are on the east side of the planet, though binoculars will probably show three. The moon closest to the planet are two moons close together, which are resolved in telescopes.

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; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Venus is seen low in the western sky at 8:15 PM tonight.
Venus is seen low in the western sky at 8:15 PM tonight March 11, 2026, or 32 minutes after sunset. Venus, at this time will be only 7½° above the horizon. Created using Stellarium.
Jupiter is seen with the bright winter stars in the south at 9:00 PM
Jupiter is seen with the bright winter stars in the south at 9:00 PM. Also showing are the zodiacal constellations of Taurus, Gemini where Jupiter is, and Cancer where it is heading to later this year . Created using stellarium.
The Moon 1 day past last quarter, as seen at 6 tomorrow morning, March 12, 2026. A view visible in small telescopes showing an image with and without selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
Telescopic Jupiter and Venus (north up) as they would be seen in a small telescope with the same magnification.
Telescopic Jupiter and Venus (north up) as they would be seen in a small telescope with the same magnification. Venus will be visible for a short time near the western horizon, while Jupiter is visible mopst of the night. Venus’ apparent diameter will be 10.3″, and be 96.6% illuminated. It’s on the far side of the Sun. Jupiter will be 41.4″ in diameter, with its moon shown here for 9 PM, tonight March 11th, 2026. The moons can shift noticable over an hour. . 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, starting with sunset on the right on March 11th, 2026. The night ends on the left with sunrise on the 12th.
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on March 11th, 2026. The night ends on the left with sunrise on the 12th. The Venus label is overprinting Saturn and its label. 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, March 11th and 12th, 2026.
This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, March 11th and 12th, 2026. 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: 03/10/2026 – Finding Cancer the crab

March 10, 2026 Comments off

This is Ephemeris for Tuesday, March 10th. Today the Sun will be up for 11 hours and 38 minutes, setting at 7:42, and it will rise tomorrow at 8:02. The Moon, 1 day before last quarter, will rise at 3:50 tomorrow morning.

The constellation of Cancer the crab is made of dim stars, which are generally connected, in constellation charts, with lines that make either the letter K or an upside down Y. It lies directly between the star pair Castor and Pollux in Gemini and Regulus in Leo. In the center of the constellation is, what to the naked-eye is a fuzzy spot called Praesepe, or the manger. The two nearby stars, one above left, and one below left are Asellus Borealis, and Asellus Australis, the northern and southern donkey colts feeding out of the manger. Viewing that fuzzy spot with a pair of binoculars will reveal that it’s not fuzzy at all. It resolves into a cluster of stars, which astronomers, over the years, have called the Beehive cluster.

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; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Finding Cancer the crab in the southeastern sky at 9 PM around mid-March 2026 in five frames.
Finding Cancer the crab in the southeastern sky at 9 PM around mid-March 2026 in five frames. First the natural sky; second, with constellation art with Gemini and Leo; third, with constellation lines; fourth, showing an inset box; fifth showing a magnified view with the Beehive cluster. Created using Stellarium, LibreOffice Draw, and GIMP.
Categories: Constellations, Ephemeris Program, Observing Tags: ,

Ephemeris: 03/09/2026 – The Great Underwater Panther in the stars

March 9, 2026 Comments off

This is Ephemeris for Monday, March 9th. Today the Sun will be up for 11 hours and 35 minutes, setting at 7:41, and it will rise tomorrow at 8:04. The Moon, 2 days before last quarter, will rise at 2:50 tomorrow morning.

As Orion tilts into the southwest at 9 PM I’m reminded of our Anishinaabek native peoples here in Michigan, who saw it as the Winter Maker slowly beginning to leave the scene in the southwest. At this time in the southeast is Curly Tail, the Great Panther. I first knew him as the Great Underwater Panther, which tells us where he lives… beneath the ice. He’s in the sky to warn us that the warmer weather of spring is coming, and the ice on the lakes and rivers is getting thin. Be careful to not fall through and drown, becoming a victim of the Great Panther. The stars of the panther include those of the head of Leo the lion the great backwards question mark, as his curly tail, to his head, the head of what we call Hydra the water snake.

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; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Great Underwater Panther finder.
Great Underwater Panther finder, looking southeast at around 9 PM or about an hour and a half after sunset. Created using Stellarium, LibreOffice Draw and GIMP.
Great Underwater Panther
The constellation Great Underwater Panther screen shot taken from the YouTube video “Stellar Connections: Explorations in Cultural Astronomy – Pt. 2” by Michael Wassegijig Price
North Hegman Lake Pictographs
North Hegman Lake Pictographs with the Wintermaker (Orion), Curly Tail or Great Underwater Panther (Leo-Hydra), and Moose (Pegasus). Credit: Etphonehome.

Categories: Anishinaabek Constellation, Ephemeris Program, Observing Tags: , , ,

Ephemeris Extra: 03/06/2026 – GTAS meeting tonight, Dr. Jerry Dobek returns to the dark side.

March 6, 2026 Comments off

Tonight at 8 p.m. at the meeting of the Grand Traverse Astronomical Society at Northwestern Michigan College’s Rogers Observatory, and on Zoom. Observatory Director Dr. Jerry Dobek will be giving a talk on what he calls dark material. This is from a new book he collaborated on: Barnard Album: A Colorful Look at Dark Nebulae. A new look at the nebulae from E. E. Barnard’s black and white photographic plates with modern color digital photography, including objects that were captured but not cataloged. Dark nebulae are clouds of gas and dust seen in the summer Milky Way. After the meeting, at 9 PM, if it’s clear there will be viewing of the skies. The observatory is located south of Traverse City on Birmley Road between Garfield and Keystone roads. Zoom instructions will be at gtastro.org.

The Barnard Album book cover.
The book cover
Categories: Uncategorized

Ephemeris: 03/06/2026 – The Fisher announces the coming of the maple sugaring season

March 6, 2026 Comments off

This is Ephemeris for Friday, March 6th. Today the Sun will be up for 11 hours and 25 minutes, setting at 6:37, and it will rise tomorrow at 7:09. The Moon, 3 days past full, will rise at 10:30 this evening.

March is a month of transitions. The stars of the winter skies, that is Orion and his merry band of bright stars, move to the west as those of spring rise in the east. The Big Dipper is ascending in the northeastern sky, after lying low in the north during the long dark evenings in the heart of winter. The dipper is the hind end of the Great Bear, officially Ursa Major. The Anishinaabe peoples of the Great Lakes region saw the Big Dipper as the hind end and tail of a magical creature called Fisher, or in their language Ojiig, who brought summer to the Earth. Its position in the sky around the pole announces the seasons. The Fisher’s ascension high into the northeastern sky signals the start of the maple sugaring season later this month.

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; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.

Addendum

The Fisher announcing maple sugaring season – animation. Star positions for 2 hours after sunset, near 45 degrees north latitude, for a week into March. Created using Stellarium and GIMP.

For the story of the Fisher, and how he got that arrow stuck in his tail, check out The story of the Fisher Star.

Categories: Anishinaabek Constellation, Ephemeris Program, Observing, Seasons Tags: , , ,

Ephemeris: 02/05/2026 – Artemis 3 isn’t going to the Moon

March 5, 2026 Comments off

This is Ephemeris for Thursday, March 5th. Today the Sun will be up for 11 hours and 22 minutes, setting at 6:36, and it will rise tomorrow at 7:11. The Moon, 2 days past full, will rise at 9:22 this evening.

Late last week NASA announced that the Artemis 3 mission was not going to land on the Moon. It wasn’t even going to the Moon. It would be a low earth orbit test of docking and operations of the Human Landing System or lunar landers, either the SpaceX Starship Lander or Blue Origin’s Blue Moon Lander. This reminds me of the Apollo 9 mission which came after the spectacular Apollo 8 mission which orbited the Moon. Apollo 9 was a checkout of the Lunar Lander in low earth orbit. Several Months later, Apollo 10 flew to the Moon to a checkout of the Lunar Lander in lunar orbit. They couldn’t land, but it was a test of the operations in preparation for Apollo 11 which successfully landed on the 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; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.

Addendum

The Space Launch System (SLS) Block 1 rocket for the Artemis 2 mission out on the launch pad.
The Space Launch System (SLS) Block 1 rocket for the Artemis 2 mission out on the launch pad. As of now, it has been trundled back to the Vertical Assembly Building (VAB) to work on a helium leak in the second stage. The two successive upgrdes to Block 1B and 2 have been canceled. It looks like commercial rockets from SpaceX and Blue Origin, which are approaching or already have exceeded its capacity will make the SLS obsolete, and be cheaper too.

Categories: Artemis Program, Ephemeris Program, NASA, Space exploration

Ephemeris: 03/04/2026 – Taking our weekly look at the whereabouts of the naked-eye planets

March 4, 2026 Comments off

This is Ephemeris for Wednesday, March 4th. Today the Sun will be up for 11 hours and 19 minutes, setting at 6:34, and it will rise tomorrow at 7:13. The Moon, 1 day past full, will rise at 8:14 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. At 7 PM or about a half hour after sunset, Venus may be seen very low in the West. Above it and a bit to the left might be Saturn which may not show up until a quarter of an hour later. We are in the last third of winter and the sunset times are increasing rapidly and taking with it Saturn. The evening sky will shift dramatically this Sunday when Daylight Saving Time returns, giving us darker mornings and brighter evenings. Jupiter is the brilliant star-like object more than halfway up in the southern sky. It’s the brightest star-like object in the sky. The planet and its moons are a treat for binoculars or a telescope.

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; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Saturn and Venus in the west-southwestern sky at 7:15 PM tonight.
Saturn and Venus in the west-southwestern sky at 7:15 PM tonight March 3, 2026, or 41 minutes after sunset. Spotting Mercury and Venus will be problematic: being too low in Venus’ case, and too faint in Saturn’s. The brightnesses of the planets are exagerated. Created using Stellarium.
Jupiter as it appears tonight, March 4, 2026, in its orientation at 9:00 PM moving against the stars of Gemini. Also shown is its track from last July to next July, and the retrograde loop that it is currently making,
Jupiter as it appears tonight, March 4, 2026, in its orientation at 9:00 PM moving against the stars of Gemini. Also shown is its track from last July to next July, and the retrograde loop that it is currently making, slowly moving to the West which it will do for the next 6 days until it stops (becomes stationary) on March 10th. Then it will resume its eastward motion. The inset shows a magnified view of the west end of the retrograde loop. Created using Stellarium, LibreOffice Draw and GIMP.
The Moon 1½ days past full, as seen tonight, March 3, 2026 at 9 PM. A view visible in small telescopes showing an image with and without selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
Jupiter is the one good planet available in a small telescope.
Jupiter is the one good planet available in a small telescope. Saturn is becoming too low in the sky to deliver a good image. This is how Jupiter will appear at 9 PM, its apparent diameter is 42.2″. 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 March 3rd, 2026. The night ends on the left with sunrise on the 4th.
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on March 3rd, 2026. 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, March 4th and 5th, 2026. 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: 03/03/2026 – Eclipse prospects for the rest of the year

March 3, 2026 Comments off

This is Ephemeris for Tuesday, March 3rd. Today the Sun will be up for 11 hours and 16 minutes, setting at 6:33, and it will rise tomorrow at 7:14. The Moon, at full today, will rise at 7:04 this evening.

If you’re listening to me right now the total lunar eclipse this morning has ended or will shortly end. In any case it’s invisible because, even if it’s ongoing, twilight has wiped it out. Then there is the possibility of clouds, which I can’t predict from when I’m recording this Sunday night. We do have another chance to view a lunar eclipse, this year, on the night of August 27-28th. It’ll be a little bit earlier. It will start late in the evening and be almost total after midnight. There’s also going to be a solar eclipse on August 12th, but it will be just a little nibble of the moon on the sun for us. It’s going to be total for the east coast of Greenland, the northern Atlantic, and northern Spain, before ending at sunset in the Mediterranean Sea.

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; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Maximums of the two eclipses visible from the Grand Traverse area in August 2026,
The maximums of the two eclipses visible from the Grand Traverse area in August of 2026. The solar eclipse of August 12th only lasts a little more than an hour, and at maximum the Moon encroaches only 11% into the Sun’s diameter. The August 28th partial lunar eclipse is more substantial. It will last three in the third hours and the Moon will immerse 93% of its diameter into the Earth’s inner shadow called the umbra, where the only sunlight to reach it filters through the Earth’s atmosphere from all the sunrises and sunsets around the world at the time. Sun and Moon images created using Stellarium.
Categories: Eclipses, Ephemeris Program, Observing Tags: , ,