Archive
Ephemeris: 01/10/2025 – Venus’ split personality
This is Ephemeris for Friday, January 10th. Today the Sun will be up for 9 hours and 4 minutes, setting at 5:22, and it will rise tomorrow at 8:18. The Moon, 3 days before full, will set at 6:40 tomorrow morning.
In very ancient times the Greeks thought that Venus in the evening as we see it now and Venus in the morning sky were two separate planets. The evening appearance was Aphrodite the goddess of love, and in the morning sky it was Phosphorus, the bringer of light, that being dawn. In Roman times Aphrodite became Venus and Phosphorus became Lucifer. It is interesting that Venus and Aphrodite are female while Phosphorus and Lucifer are male. Another term for Venus which I even use colloquially, is Evening Star for its current location and Morning Star in the morning sky, even though it’s a planet not a star. Venus is a beautiful planet in our sky, but a hellish planet in reality. No wonder Elon Musk would rather go to Mars than the much closer Venus.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Ephemeris: 01/09/2025 – Venus is at its greatest separation from the Sun today
This is Ephemeris for Thursday, January 9th. Today the Sun will be up for 9 hours and 2 minutes, setting at 5:21, and it will rise tomorrow at 8:18. The Moon, 3 days past first quarter, will set at 5:25 tomorrow morning.
Tonight, Venus will be at its greatest separation from the Sun in the sky at a little bit more than a 47° angle. Venus, being inside the Earth’s orbit, can ever stray far from the Sun. So today it is at its greatest eastern elongation from the Sun. For the rest of winter it will be moving closer to the Sun from our perspective. Crossing between the Earth and the Sun on March 22nd. During this period of time Venus will be a great object for the telescope, as it moves closer to the Earth and gets larger in telescopes and its phase, moving from being like a quarter moon to a very thin crescent near the end of winter. At inferior conjunction with the Sun, Venus will be only 26 million miles away from us, but quite invisible in the Sun’s glare.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
The Mayan civilization of Central America had several calendars. One of them was based on the planet Venus. They discovered that Venus repeated its positions in the sky with respect with the seasonal calendar over a period of eight years, which they called a Venus Sequence. They paid close attention to Venus and discovered it appeared to go around the Sun in the sky in 584 days, which they called a Venus Cycle. We call it Venus’ synodic period, which is the number of days between inferior conjunction, when Venus passes between the Earth and the Sun, then moves through the morning sky, and disappears behind the Sun at superior conjunction, then appears in the evening sky and back to inferior conjunction again. The gray area in the diagram is where Venus is not visible because it’s too close to the sun. However, at our latitude the number of days that Venus is invisible varies with the season. The Mayans, being in the tropics, didn’t have as much variation as we do. The Mayans discovered that Venus completed 5 cycles in almost exactly 8 years.
Today, Venus is at its greatest eastern elongation. On March 22nd Venus will pass inferior conjunction. That is 72 days from today. So it spends most of its time, 7 months, moving from around behind the Sun to the greatest elongation and only a short time, about 2 1/2 months moving from there to inferior conjunction. These 2 1/2 months are the best time to view Venus with a telescope, since Venus will grow in size and become an ever thinning crescent.
Check out my Wednesday posts showing the ever-growing and thinning Venus crescent until March 22nd. Or better yet, see it for yourself with a small telescope.
Ephemeris: 01/08/2025 – A weekly look at the whereabouts of the naked-eye planets
This is Ephemeris for Wednesday, January 8th. Today the Sun will be up for 9 hours and 1 minute, setting at 5:20, and it will rise tomorrow at 8:18. The Moon, 2 days past first quarter, will set at 4:05 tomorrow morning.
Let’s take our weekly look at the whereabouts of the naked-eye planets. At 8:00 PM this evening four of the five naked eye planets will be out. Starting from the West we have Venus the brightest of all low in the west southwest. Above and left of that is Saturn. The waxing gibbous moon is high in the South at that time. Jupiter, the second-brightest planet will be high in the southeast. The 4th planet out is Mars which is low in the east northeast with its reddish hue giving it away. Next Monday the Moon will pass directly over the planet Mars in our evening sky. The fifth naked eye planet, Mercury, is too close to the Sun on it morning side to be visible.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Ephemeris: 01/07/25 – Lights in the sky: Sirius, the brightest star
This is Bob Moler with Ephemeris for Tuesday, January 7th. Today the Sun will be up for 8 hours and 59 minutes, setting at 5:19, and it will rise tomorrow at 8:19. The Moon, 1 day past first quarter, will set at 2:45 tomorrow morning.
The brightest star in the nighttime sky, Sirius, will rise about 7:30 this evening in the east-southeast. By 9 PM it will be low in the southeast. It is also known as the Dog Star because it’s located in Orion’s greater hunting dog, Canis Major. However, its name Sirius means Dazzling One, or Scorcher, alluding to its great brightness. Sirius is about twice as massive as the Sun, but 25 times brighter, It is one of the nearer stars, being about 8.7 light years away, about twice the distance of Alpha Centauri. Sirius is a pure white star as opposed to the sun’s somewhat yellowish cast. It seems to really sparkle in a pair of binoculars. The sparkling or the twinkling of Sirius or of any star is not due to the star itself but by turbulence in Earth’s atmosphere.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Ephemeris: 01/06/2025 – Things that go blink in the night
This is Ephemeris for Monday, January 6th. Today the Sun will be up for 8 hours and 58 minutes, setting at 5:18, and it will rise tomorrow at 8:19. The Moon, at first quarter today, will set at 1:26 tomorrow morning.
Lately there’s been a lot of reported observations of drones or various things in the sky at night, especially, for some reason, in New Jersey. If it’s something that’s moving in the sky other than satellites, meteors and aurorae, they’re out of my wheelhouse. I generally concern myself with the sidereal universe, the universe beyond the atmosphere. Things that don’t seem to move that rapidly. There are a lot of bright lights in the sky, that are things that I can and do talk about this time of year and this particular year. We have a lot of bright lights in the sky now, foremost Venus in the southwest in the early evening, and Jupiter in the east and the south. Mars is also up, but it’s not in competition with Jupiter this year. These plus the bright winter stars.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Ephemeris: 01/03/2025 – GTAS Telescope Clinic tonight
This is Ephemeris for Friday, January 3rd. The Sun will rise at 8:20. It’ll be up for 8 hours and 55 minutes, setting at 5:15. The Moon, 3 days before first quarter, will set at 9:37 this evening.
Did you or someone in your family get a telescope for Christmas, or have one in a closet or attic because you don’t know how to put it together or how to operate it? Or maybe you are trying to figure out which one to buy. Well, tonight’s your night. The Grand Traverse Astronomical Society (GTAS) will host the annual Telescope Clinic starting at 8 pm at Northwestern Michigan College’s Rogers Observatory. Professor Jerry Dobek will demonstrate the types of telescopes and how to use them. He and other members may be able to help particular problems by seeing participants telescopes, so “bring ‘em if you’ve got ‘em.” This is interesting to say the least. Go to gtastro.org for information and a Zoom link for the meeting.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Ephemeris: 01/02/2025 – Today we have the latest sunrise
This is Bob Moler with Ephemeris for Thursday, January 2nd. The Sun will rise at 8:20. It’ll be up for 8 hours and 54 minutes, setting at 5:14. The Moon, 3 days past new, will set at 8:20 this evening. | As an amateur astronomer I am fascinated by time, the so-called 4th dimension. For example, being at the right place at the right time such as to view a total solar eclipse. The universe isn’t going to wait for you if you’re off in the three dimensions of location or of the time. But today is a different story. Today is the day of the latest sunrise, which is at 8:20 AM. From today to June 15th, the day of the earliest sunrise, is on average about 165 days. That’s about 5 ½ months. We had our earliest sunset back on December 9th. That was 24 days ago so it’s got a head start from there to the latest sunset that it will need because the latest sunset will be on June 26th. So the sunrise times will decrease faster than the sunset times will increase into the June summer solstice period.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum:
Ephemeris: 01/01/2025 – A New Year’s Day look at the naked-eye planets
This is Ephemeris for New Year’s Day, Wednesday, January 1st, 2025. The Sun will rise at 8:20. It’ll be up for 8 hours and 53 minutes, setting at 5:13. The Moon, 2 days past new, will set at 7:02 this evening.
Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus can be spotted in the south-southwestern sky by 5:45 PM, about 30 minutes after sunset, and will also be above and left of the thin crescent Moon. Venus will set at 9:10 PM. Saturn will be in the south-southwestern sky at 6 PM, above and left of Venus, which will be seen to cross paths with it on the 18th of this month. Jupiter is low in the east, about the same time Venus is first spotted. It will be a good object for the small telescope. Mars, rises tonight at 6:31. Mars is still considered a morning planet since it is still up at sunrise. But that will end on the 15th of this month, when Mars reaches opposition from the Sun.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Happy New Year! I do really hope it will be happy…
Addendum
Ephemeris: 12/31/2024 – Previewing January’s skies
This is Ephemeris for New Year’s Eve, Tuesday, December 31st. The Sun will rise at 8:20. It’ll be up for 8 hours and 52 minutes, setting at 5:12. The Moon, 1 day past new, will set at 5:46 this evening.
Let’s look ahead at the month of January 2025. Thursday we will have our latest sunrise at 8:20. That time will drop to 8:02 by the 31st. Sunset times are already increasing. On the 1st at 5:13, will extend to 5:50 at month’s end, which will push the daylight hours to 9 hours 47 minutes by then. The altitude of the Sun at local noon will increase from under 23 degrees tomorrow to 28 degrees at month’s end. Tomorrow we will reach our closest distance from the Sun of the year at 91.4 million miles. Friday morning will see the peak of the Quadrantid meteor shower. They will be best seen in the early morning and seem to come from near the handle of the Big Dipper, where possibly more than 60 meteors an hour might be seen.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
January Evening Star Chart
The planets and stars are plotted for the 15th at 9 PM EST in the evening and 6 AM on the 16th 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), so the skies may not exactly match as seen from other locations.
January Morning Star Chart
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.
- The leaky bowl of the Big Dipper drips on Leo.
- Follow the arc of the handle of the Big Dipper to the star Arcturus, then
- Follow the spike to Spica.
- QuadR on the star charts is the radiant of the Quadrantid meteor shower which peaks on the 4th at 4:14 a.m. EST (9:14 UT).
Twilight Limits, Nautical and Astronomical
| EST | |||||||
| Morning | Twilight | Evening | Twilight | Dark | Night | Moon | |
| Date | Astro. | Nautical | Nautical | Astro. | Start | End | Illum. |
| 2025-01-01 | 6h35m | 7h11m | 18h22m | 19h02m | 19h03m | 6h35m | 0.06 |
| 2025-01-02 | 6h35m | 7h11m | 18h23m | 19h02m | 20h21m | 6h35m | 0.12 |
| 2025-01-03 | 6h35m | 7h11m | 18h24m | 19h03m | 21h38m | 6h35m | 0.2 |
| 2025-01-04 | 6h35m | 7h11m | 18h25m | 19h04m | 22h54m | 6h35m | 0.3 |
| 2025-01-05 | 6h35m | 7h11m | 18h26m | 19h05m | – | 6h35m | 0.41 |
| 2025-01-06 | 6h35m | 7h11m | 18h27m | 19h06m | 0h10m | 6h35m | 0.53 |
| 2025-01-07 | 6h35m | 7h11m | 18h28m | 19h07m | 1h27m | 6h35m | 0.64 |
| 2025-01-08 | 6h35m | 7h10m | 18h29m | 19h08m | 2h45m | 6h35m | 0.74 |
| 2025-01-09 | 6h35m | 7h10m | 18h30m | 19h09m | 4h06m | 6h35m | 0.84 |
| 2025-01-10 | 6h35m | 7h10m | 18h31m | 19h10m | 5h26m | 6h35m | 0.91 |
| 2025-01-11 | 6h35m | 7h10m | 18h32m | 19h11m | – | – | 0.96 |
| 2025-01-12 | 6h34m | 7h09m | 18h33m | 19h12m | – | – | 0.99 |
| 2025-01-13 | 6h34m | 7h09m | 18h34m | 19h13m | – | – | 1 |
| 2025-01-14 | 6h34m | 7h09m | 18h35m | 19h14m | – | – | 0.98 |
| 2025-01-15 | 6h34m | 7h08m | 18h36m | 19h15m | 19h15m | 19h28m | 0.94 |
| 2025-01-16 | 6h33m | 7h08m | 18h37m | 19h16m | 19h16m | 20h38m | 0.89 |
| 2025-01-17 | 6h33m | 7h07m | 18h38m | 19h17m | 19h17m | 21h45m | 0.82 |
| 2025-01-18 | 6h32m | 7h07m | 18h39m | 19h18m | 19h18m | 22h49m | 0.74 |
| 2025-01-19 | 6h32m | 7h06m | 18h41m | 19h19m | 19h19m | 23h52m | 0.65 |
| 2025-01-20 | 6h31m | 7h06m | 18h42m | 19h20m | 19h20m | – | 0.56 |
| 2025-01-21 | 6h31m | 7h05m | 18h43m | 19h21m | 19h21m | 0h56m | 0.47 |
| 2025-01-22 | 6h30m | 7h05m | 18h44m | 19h23m | 19h23m | 2h01m | 0.37 |
| 2025-01-23 | 6h29m | 7h04m | 18h45m | 19h24m | 19h24m | 3h08m | 0.28 |
| 2025-01-24 | 6h29m | 7h03m | 18h47m | 19h25m | 19h25m | 4h16m | 0.2 |
| 2025-01-25 | 6h28m | 7h02m | 18h48m | 19h26m | 19h26m | 5h22m | 0.12 |
| 2025-01-26 | 6h27m | 7h02m | 18h49m | 19h27m | 19h27m | 6h24m | 0.06 |
| 2025-01-27 | 6h26m | 7h01m | 18h50m | 19h28m | 19h28m | 6h26m | 0.02 |
| 2025-01-28 | 6h26m | 7h00m | 18h51m | 19h30m | 19h30m | 6h26m | 0 |
| 2025-01-29 | 6h25m | 6h59m | 18h53m | 19h31m | 19h31m | 6h25m | 0.01 |
| 2025-01-30 | 6h24m | 6h58m | 18h54m | 19h32m | 19h32m | 6h24m | 0.04 |
| 2025-01-31 | 6h23m | 6h57m | 18h55m | 19h33m | 20h40m | 6h23m | 0.09 |
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
Jan 1 We Venus: 47° E
3 Fr 10:24 AM Moon-Venus: 1.5° N
3 Fr 10:24 AM Quadrantid Shower: ZHR = 120
4 Sa 2:59 AM Perihelion: 0.9833 AU
4 Sa 12:18 PM Moon-Saturn: 0.7° S
5 Su 2:46 PM Moon Ascending Node
6 Mo 6:56 PM First Quarter
7 Tu 6:35 PM Moon Perigee: 370200 km
9 Th 8:01 PM Moon-Pleiades: 0.3° S
9 Th 10:59 PM Venus Greatest Elongation: 47.2° E
11 Sa 11:30 PM Moon North Dec.: 28.5° N
13 Mo 4:45 PM Moon-Pollux: 2.2° N
13 Mo 5:27 PM Full Moon
13 Mo 10:42 PM Moon-Mars: 0.2° S Occultation!
14 Tu 4:03 PM Moon-Beehive: 2.7° S
15 We 8:17 PM Mars Opposition
16 Th 9:57 AM Moon-Regulus: 2.4° S
18 Sa 10:53 AM Venus-Saturn: 2.2° N
18 Sa 8:48 PM Moon Descending Node
20 Mo 10:53 PM Moon-Spica: 0.1° N
20 Mo 11:55 PM Moon Apogee: 404300 km
21 Tu 3:31 PM Last Quarter
23 Th 12:05 PM Mars-Pollux: 2.4° S
24 Fr 6:34 PM Moon-Antares: 0.3° N
26 Su 8:27 AM Moon South Dec.: 28.5° S
29 We 7:36 AM New Moon
31 Fr 5:02 PM Jupiter-Aldebaran: 5.2° N
31 Fr 11:46 PM Moon-Saturn: 1.1° S
Feb 1 Sa Venus: 45° E
All event times are given for UTC-5 Eastern Standard Time.
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.
Sun and Moon Rising and Setting Events
LU Ephemeris of Sky Events for Interlochen/TC
January, 2025 Local time zone: EST
+-----------------------------------------------------------------------+
| DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM |
| | RISE SET HOURS | END START |PHASE SET** TIME FRACTN|
+=======================================================================+
|Wed 1| 08:20a 05:13p 08:53 | 06:23p 07:09a | Set 07:02p 5%|
|Thu 2| 08:20a 05:14p 08:54 | 06:24p 07:09a | Set 08:20p 11%|
|Fri 3| 08:20a 05:15p 08:55 | 06:25p 07:10a | Set 09:37p 19%|
|Sat 4| 08:20a 05:16p 08:56 | 06:26p 07:10a | Set 10:54p 28%|
+------+-----------------------+----------------+-----------------------+
|Sun 5| 08:19a 05:17p 08:57 | 06:27p 07:10a | Set 12:09a 39%|
|Mon 6| 08:19a 05:18p 08:58 | 06:28p 07:09a |F Qtr Set 01:26a 50%|
|Tue 7| 08:19a 05:19p 08:59 | 06:29p 07:09a | Set 02:45a 61%|
|Wed 8| 08:19a 05:20p 09:01 | 06:30p 07:09a | Set 04:05a 72%|
|Thu 9| 08:18a 05:21p 09:02 | 06:31p 07:09a | Set 05:25a 82%|
|Fri 10| 08:18a 05:22p 09:04 | 06:32p 07:09a | Set 06:40a 89%|
|Sat 11| 08:18a 05:23p 09:05 | 06:33p 07:09a | Set 07:43a 95%|
+------+-----------------------+----------------+-----------------------+
|Sun 12| 08:17a 05:25p 09:07 | 06:34p 07:08a | Set 08:34a 99%|
|Mon 13| 08:17a 05:26p 09:08 | 06:35p 07:08a |Full Rise 05:00p 100%|
|Tue 14| 08:16a 05:27p 09:10 | 06:36p 07:08a | Rise 06:14p 99%|
|Wed 15| 08:16a 05:28p 09:12 | 06:37p 07:07a | Rise 07:27p 95%|
|Thu 16| 08:15a 05:30p 09:14 | 06:38p 07:07a | Rise 08:37p 90%|
|Fri 17| 08:15a 05:31p 09:16 | 06:39p 07:06a | Rise 09:44p 83%|
|Sat 18| 08:14a 05:32p 09:18 | 06:40p 07:06a | Rise 10:48p 76%|
+------+-----------------------+----------------+-----------------------+
|Sun 19| 08:13a 05:34p 09:20 | 06:42p 07:05a | Rise 11:52p 67%|
|Mon 20| 08:13a 05:35p 09:22 | 06:43p 07:05a | Rise 12:56a 58%|
|Tue 21| 08:12a 05:36p 09:24 | 06:44p 07:04a |L Qtr Rise 02:01a 49%|
|Wed 22| 08:11a 05:38p 09:26 | 06:45p 07:03a | Rise 03:07a 39%|
|Thu 23| 08:10a 05:39p 09:28 | 06:46p 07:03a | Rise 04:15a 30%|
|Fri 24| 08:09a 05:40p 09:31 | 06:48p 07:02a | Rise 05:22a 22%|
|Sat 25| 08:08a 05:42p 09:33 | 06:49p 07:01a | Rise 06:24a 14%|
+------+-----------------------+----------------+-----------------------+
|Sun 26| 08:07a 05:43p 09:35 | 06:50p 07:00a | Rise 07:17a 8%|
|Mon 27| 08:06a 05:44p 09:38 | 06:51p 07:00a | Rise 08:00a 3%|
|Tue 28| 08:05a 05:46p 09:40 | 06:52p 06:59a | Rise 08:34a 0%|
|Wed 29| 08:04a 05:47p 09:42 | 06:54p 06:58a |New Set 06:00p 0%|
|Thu 30| 08:03a 05:49p 09:45 | 06:55p 06:57a | Set 07:20p 3%|
|Fri 31| 08:02a 05:50p 09:47 | 06:56p 06:56a | Set 08:39p 8%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise
Generated using my LookingUp for DOS program.
Ephemeris: 12/30/2024 – Two great astronomical events of 2024
This is Ephemeris for Monday, December 30th. Today the Sun will be up for 8 hours and 51 minutes, setting at 5:11, and it will rise tomorrow at 8:20. The Moon is new today, and won’t be visible.
Speaking of new moons, the most spectacular astronomical event of 2024 was the total solar eclipse of April 8th. The path of totality came fairly close to us here in Northern Michigan just clipping the southeastern corner of the state. It was my sixth observation of a total solar eclipse out of six tries and probably my last, because our next total solar eclipse in the contiguous 48 states will be twenty-one years from now in 2045. The other event of 2024 was the appearance of the Comet Tsuchinshan-ATLAS which graced our skies for a few days in mid-October. I have no reports of anybody seeing it with the naked eye, however it was visible in binoculars and easily photographed with a few seconds exposure with a camera. It had a very prominent tail.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Bob Moler's Ephemeris Blog 