Archive
Ephemeris: 01/04/2024 – Viewing Orion’s Belt
This is Ephemeris for Thursday, January 4th. The Sun will rise at 8:20. It’ll be up for 8 hours and 55 minutes, setting at 5:15. The Moon, 1 day past last quarter, will rise at 2:10 tomorrow morning.
Orion’s belt of three stars is one of the most noticeable star groupings in the sky. There are no other groups of three bright stars in a straight line visible anywhere else in the sky. The star’s names from left to right are Alnitak, Alnilam and Mintaka. They are actually a bit farther away than the other bright stars of Orion. Alnilam, the center star, is over three times the distance of red giant Betelgeuse above them and over twice as far as blue white giant star Rigel below them. Alnilam is 375 thousand times brighter than the Sun. These three stars were also known as Frigga’s Spindle by the Norsemen. Frigga, also known as Freya, is the goddess from which we get the name of the day of the week we call Friday.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.
Addendum
Ephemeris: 01/03/2024 – Where have the naked-eye planets wandered off to this week?
This is Ephemeris for Wednesday, January 3rd. The Sun will rise at 8:20. It’ll be up for 8 hours and 54 minutes, setting at 5:14. The Moon, at last quarter today, will rise at 1:04 tomorrow morning.
Let’s find out where the naked-eye planets have wandered off to this week. Four of those five planets are now visible. Mars rises too close to sunrise to be seen. Saturn and Jupiter are the only evening planets. Saturn can be seen moving from low in the southwest to setting in the west-southwest at 9:30 pm. Jupiter will be moving from the high in the south-southeast to the west-southwest, by midnight and will set at 2:57 am. The last quarter Moon will be in Virgo tomorrow morning. Venus, the brilliant morning star, will rise in the east-southeast at 5:29 am, and be a brilliant beacon in the morning, shining in the southeast before the bright morning twilight claims it around 8 am. Mercury may be glimpsed below and left of it.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.
Addendum
Ephemeris Extra: 01/02/2024 – Two remarkable astronomical events for 2024
Ephemeris Extra posts are freestanding posts not tied to a specific Ephemeris radio program on Interlochen Public Radio
Total Solar Eclipse, April 8th
The big astronomical event of 2024, for us in Michigan, will be the total eclipse of the Sun, on the afternoon of Monday, April 8th. The path of totality will just clip the southeastern corner of Michigan by a few miles, so if you want to see the best of totality you need to leave the state. Totality is when the Moon completely covers the brilliant face of the Sun and allows the Sun’s silvery corona to be seen. Totality is the only part of the eclipse that can be viewed without eye protection or by projection.
Two relatively nearby large cities that will see totality are Indianapolis and Cleveland. Parts of Indianapolis will get to see more than 4 minutes of totality. Cleveland will see a little less. The closer you are to the center line of that path the longer totality will last.
For an interactive map of the eclipse path on the Internet, go to eclipse2024.org/eclipse_cities/statemap.html
Weather is always a concern for eclipses. In general the farther south one goes the better the chances there are for clear skies. But all bets are off for eclipse day: It’s gonna be is what it’s gonna be. My current inclination is to head southwest along the eclipse path.
For those staying home and not chasing the shadow of the Moon will see a partial eclipse here with up to 87% of the Sun being blocked by the Moon.
Comet Tsuchinshan-ATLAS
We expect to see a new bright comet in October: C/2023 A3 (Tsuchinshan-ATLAS), otherwise known in this article as A3 for short. It may be the brightest comet to appear in our Northern Michigan skies since Comet Hale-Bopp in 1997, and a good deal brighter than 2020’s Comet NEOWISE. At least we’re hoping.
This comet was discovered last January by the station Xi Yi of the Purple Mountain Observatory in China, and a month later by the ATLAS search program on Maui. ATLAS is an acronym for the apocalyptic sounding Asteroid Terrestrial-Impact Last Alert System.
A3 will best be visible from Northern Michigan toward mid-October in the evening, not long after sunset. The comet is expected to reach magnitude 0 at it’s closest to the Sun in late September. However, we will be seeing it best as it’s leaving the vicinity of the Sun. By mid-October its magnitude will have dropped to magnitude 1 which is still pretty bright, and it will be moving at a high angle away from the setting Sun, so it will rapidly increase its distance from the Sun and the horizon faster than it fades in the latter part of October. That is, if it behaves itself. Comets are notoriously fickle in their brightness so we won’t know until we actually see it how bright it’ll be, or how bright or long its tail will be. As of this writing (Mid-December) A3’s brightness is tracking as predicted, at about 16th magnitude. As of January 1st its distance from the Sun was 4.24 AU, about 1 AU inside Jupiter’s orbit. 1 AU (Astronomical Unit) is the mean distance between the Earth and the Sun. The comet can be followed on Seiichi Yoshida’s Weekly Information about Bright Comets webpage: http://www.aerith.net/comet/catalog/2023A3/2023A3.html
Ephemeris: 01/02/2024 – We’re closest to the Sun today
This is Ephemeris for Tuesday, January 2nd. The Sun will rise at 8:20. It’ll be up for 8 hours and 53 minutes, setting at 5:13. The Moon, 1 day before last quarter, will rise at 12:01 tomorrow morning.
We start off the year with the Earth being really close to the Sun. As a matter of fact at 6:59 pm the Earth will reach perihelion, that is as close as it gets to the Sun for the entire year at 91.41 million miles (147.10 million kilometers). It’s not as big a deal as it seems, because the Earth varies only plus or minus a million and a half miles from the Sun over the year out of 93 million miles. It doesn’t make much difference in the amount of heat we get from the Sun. However, it’s much less than what the tilt of the Earth’s axis does to give us our seasons, but what it does do is alter the length of the seasons, and makes winter the shortest season. It’s shorter by about four days than summer, even though in Northern Michigan it doesn’t really seem like it. Today is also the date of the latest sunrise of the year.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.
Addendum
Ephemeris Extra: 01/01/2024 – Previewing January skies
This post didn’t make it into a radio program, so enjoy.
We start a new year and a month. The daylight hours start slowly getting longer and will accelerate during the month. Daylight hours in Interlochen and Traverse City will increase from 8 hours and 52 minutes on the 1st to 9 hours and 46 minutes on the 31st. The sunrise time will decrease from 8:20 am on the 1st to 8:03 am at month’s end. The sunset times will increase from 5:12 pm on the 1st to 5:49 pm on the 31st. Along with that the altitude of the sun at noon will increase from 22 degrees tomorrow to nearly 28 degrees at month’s end. It will be a degree lower for folks in the Straits area because they are a degree of latitude farther north. Local noon, by the way for Interlochen and Traverse City is around 12:51 p.m. in January.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.
January Evening Star Chart
The planets and stars are plotted for the 15th at 9 p.m. EST in the evening and 6 a.m. for the morning chart. These are the chart times. The brilliant planet Venus will enter the sky at the chart time during the latter half of the month in the southwest. 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).
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 3:20 a.m. EST (8:20 UT).
Twilight Limits, Nautical and Astronomical
| EST | |||||||
| Morning | Twilight | Evening | Twilight | Dark | Night | Moon | |
| Date | Astro. | Nautical | Nautical | Astro. | Start | End | Illum. |
| 2024-01-01 | 6h35m | 7h11m | 18h22m | 19h01m | 19h01m | 22h59m | 0.68 |
| 2024-01-02 | 6h35m | 7h11m | 18h22m | 19h02m | 19h02m | – | 0.59 |
| 2024-01-03 | 6h35m | 7h11m | 18h23m | 19h03m | 19h03m | 0h01m | 0.50 |
| 2024-01-04 | 6h35m | 7h11m | 18h24m | 19h03m | 19h03m | 1h05m | 0.40 |
| 2024-01-05 | 6h35m | 7h11m | 18h25m | 19h04m | 19h04m | 2h10m | 0.30 |
| 2024-01-06 | 6h35m | 7h11m | 18h26m | 19h05m | 19h05m | 3h19m | 0.21 |
| 2024-01-07 | 6h35m | 7h11m | 18h27m | 19h06m | 19h06m | 4h31m | 0.13 |
| 2024-01-08 | 6h35m | 7h11m | 18h28m | 19h07m | 19h07m | 5h45m | 0.07 |
| 2024-01-09 | 6h35m | 7h10m | 18h29m | 19h08m | 19h08m | 6h35m | 0.02 |
| 2024-01-10 | 6h35m | 7h10m | 18h30m | 19h09m | 19h09m | 6h35m | 0.00 |
| 2024-01-11 | 6h35m | 7h10m | 18h31m | 19h10m | 19h10m | 6h35m | 0.01 |
| 2024-01-12 | 6h35m | 7h10m | 18h32m | 19h11m | 19h11m | 6h35m | 0.04 |
| 2024-01-13 | 6h34m | 7h09m | 18h33m | 19h12m | 20h14m | 6h34m | 0.10 |
| 2024-01-14 | 6h34m | 7h09m | 18h34m | 19h13m | 21h36m | 6h34m | 0.18 |
| 2024-01-15 | 6h34m | 7h09m | 18h35m | 19h14m | 22h55m | 6h34m | 0.28 |
| 2024-01-16 | 6h33m | 7h08m | 18h36m | 19h15m | – | 6h33m | 0.39 |
| 2024-01-17 | 6h33m | 7h08m | 18h37m | 19h16m | 0h12m | 6h33m | 0.51 |
| 2024-01-18 | 6h33m | 7h07m | 18h39m | 19h17m | 1h28m | 6h33m | 0.62 |
| 2024-01-19 | 6h32m | 7h07m | 18h40m | 19h18m | 2h44m | 6h32m | 0.72 |
| 2024-01-20 | 6h32m | 7h06m | 18h41m | 19h20m | 3h59m | 6h32m | 0.81 |
| 2024-01-21 | 6h31m | 7h06m | 18h42m | 19h21m | 5h12m | 6h31m | 0.88 |
| 2024-01-22 | 6h30m | 7h05m | 18h43m | 19h22m | 6h18m | 6h30m | 0.94 |
| 2024-01-23 | 6h30m | 7h04m | 18h44m | 19h23m | – | – | 0.98 |
| 2024-01-24 | 6h29m | 7h04m | 18h46m | 19h24m | – | – | 1.00 |
| 2024-01-25 | 6h28m | 7h03m | 18h47m | 19h25m | – | – | 1.00 |
| 2024-01-26 | 6h28m | 7h02m | 18h48m | 19h26m | – | – | 0.98 |
| 2024-01-27 | 6h27m | 7h01m | 18h49m | 19h28m | 19h28m | 19h44m | 0.95 |
| 2024-01-28 | 6h26m | 7h00m | 18h51m | 19h29m | 19h29m | 20h48m | 0.90 |
| 2024-01-29 | 6h25m | 7h00m | 18h52m | 19h30m | 19h30m | 21h51m | 0.83 |
| 2024-01-30 | 6h24m | 6h59m | 18h53m | 19h31m | 19h31m | 22h53m | 0.76 |
| 2024-01-31 | 6h24m | 6h58m | 18h54m | 19h32m | 19h32m | 23h57m | 0.67 |
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 Mo Venus: 37.4° W
1 Mo 10:28 am Moon Apogee: 404900 km
2 Tu 6:59 pm Perihelion: .9833 AU
3 We 10:30 pm Last Quarter
4 Th 4:15 am Quadrantid Shower: ZHR = 120
4 Th 1:52 pm Moon Descending Node
4 Th 6:06 pm Moon-Spica: 2.2° S
6 Sa 7:35 pm Venus-Antares: 6.3° N
8 Mo 9:24 am Moon-Antares: .8° S
8 Mo 3:12 pm Moon-Venus: 5.9° N
10 We 2:04 am Moon South Dec.: 28.2° S
11 Th 6:57 am New Moon
12 Fr 8:59 am Mercury Elongation: 23.5° W
13 Sa 5:35 am Moon Perigee: 362300 km
14 Su 4:31 am Moon-Saturn: 2.1° N
17 We 9:05 am Moon Ascending Node
17 We 10:53 pm First Quarter
18 Th 3:40 pm Moon-Jupiter: 2.9° S
20 Sa 8:25 am Moon-Pleiades: .9° N
22 Mo 10:44 pm Moon North Dec.: 28.2° N
24 We 2:00 pm Moon-Pollux: 1.9° N
25 Th 12:54 pm Full Moon
25 Th 3:04 pm Moon-Beehive: 3.6° S
27 Sa 10:48 am Mercury-Mars: .2° N
29 Mo 3:14 am Moon Apogee: 405800 km
31 We 3:17 pm Moon Descending Node
Feb 1 Th Venus: 30.8° W
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, 2024 Local time zone: EST
+-----------------------------------------------------------------------+
| DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM |
| | RISE SET HOURS | END START |PHASE SET** TIME FRACTN|
+=======================================================================+
|Mon 1| 08:20a 05:12p 08:52 | 06:22p 07:09a | Rise 10:58p 70%|
|Tue 2| 08:20a 05:13p 08:53 | 06:23p 07:09a | Rise 12:01a 61%|
|Wed 3| 08:20a 05:14p 08:54 | 06:24p 07:09a |L Qtr Rise 01:04a 51%|
|Thu 4| 08:20a 05:15p 08:55 | 06:25p 07:10a | Rise 02:10a 42%|
|Fri 5| 08:20a 05:16p 08:56 | 06:26p 07:10a | Rise 03:18a 32%|
|Sat 6| 08:19a 05:17p 08:57 | 06:27p 07:09a | Rise 04:30a 23%|
+------+-----------------------+----------------+-----------------------+
|Sun 7| 08:19a 05:18p 08:58 | 06:28p 07:09a | Rise 05:45a 15%|
|Mon 8| 08:19a 05:19p 09:00 | 06:29p 07:09a | Rise 06:58a 8%|
|Tue 9| 08:19a 05:20p 09:01 | 06:30p 07:09a | Rise 08:04a 3%|
|Wed 10| 08:18a 05:21p 09:02 | 06:31p 07:09a | Rise 08:59a 1%|
|Thu 11| 08:18a 05:23p 09:04 | 06:32p 07:09a |New Set 05:25p 1%|
|Fri 12| 08:18a 05:24p 09:06 | 06:33p 07:09a | Set 06:49p 3%|
|Sat 13| 08:17a 05:25p 09:07 | 06:34p 07:08a | Set 08:14p 9%|
+------+-----------------------+----------------+-----------------------+
|Sun 14| 08:17a 05:26p 09:09 | 06:35p 07:08a | Set 09:36p 17%|
|Mon 15| 08:16a 05:27p 09:11 | 06:36p 07:08a | Set 10:55p 26%|
|Tue 16| 08:16a 05:29p 09:12 | 06:37p 07:07a | Set 12:12a 37%|
|Wed 17| 08:15a 05:30p 09:14 | 06:38p 07:07a |F Qtr Set 01:28a 48%|
|Thu 18| 08:15a 05:31p 09:16 | 06:40p 07:06a | Set 02:43a 59%|
|Fri 19| 08:14a 05:33p 09:18 | 06:41p 07:06a | Set 03:59a 69%|
|Sat 20| 08:13a 05:34p 09:20 | 06:42p 07:05a | Set 05:11a 79%|
+------+-----------------------+----------------+-----------------------+
|Sun 21| 08:12a 05:35p 09:22 | 06:43p 07:05a | Set 06:17a 86%|
|Mon 22| 08:12a 05:37p 09:24 | 06:44p 07:04a | Set 07:14a 93%|
|Tue 23| 08:11a 05:38p 09:27 | 06:45p 07:03a | Set 08:00a 97%|
|Wed 24| 08:10a 05:39p 09:29 | 06:47p 07:03a | Set 08:36a 99%|
|Thu 25| 08:09a 05:41p 09:31 | 06:48p 07:02a |Full Rise 05:30p 100%|
|Fri 26| 08:08a 05:42p 09:33 | 06:49p 07:01a | Rise 06:37p 98%|
|Sat 27| 08:07a 05:43p 09:36 | 06:50p 07:00a | Rise 07:43p 95%|
+------+-----------------------+----------------+-----------------------+
|Sun 28| 08:06a 05:45p 09:38 | 06:52p 06:59a | Rise 08:47p 91%|
|Mon 29| 08:05a 05:46p 09:41 | 06:53p 06:59a | Rise 09:50p 84%|
|Tue 30| 08:04a 05:48p 09:43 | 06:54p 06:58a | Rise 10:53p 77%|
|Wed 31| 08:03a 05:49p 09:46 | 06:55p 06:57a | Rise 11:56p 69%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset
Generated using my LookingUp for DOS program.
Ephemeris: 01/01/2024 – Why does the year start on January 1st?
Happy New Year! This is Ephemeris for New Year’s Day, Monday, January 1st 2024. The Sun will rise at 8:20. It’ll be up for 8 hours and 52 minutes, setting at 5:12. The Moon, 2 days before last quarter, will rise at 10:58 this evening.
Here we are January 1st the start of a new year. So why does the year start on January 1st? For a long time the Romans started their year in the middle of March near the vernal equinox, the Ides of March to be specific. The Hebrew calendar was the lunar calendar of either 12 or 13 months in a year so that 19 years in their lunar calendar was exactly 19 years on the Roman or Julian solar calendar. The Greeks until Roman times had a lunar calendar dictated haphazardly by every city state. Their year started with the summer solstice around mid-June. The Romans initially had a 10-month calendar. When they finally added those two months, the first they named after the god Janus the god of beginnings and endings, who had two faces, looking backward to the past and forward to the future.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.
Addendum
Bob Moler's Ephemeris Blog 