Archive
Ephemeris: 03/08/2024 – We’re one month away from the last Great American Eclipse for the next 21 years
This is Bob Moler with Ephemeris for International Women’s Day, Friday, March 8th. Today the Sun will be up for 11 hours and 33 minutes, setting at 6:40, and it will rise tomorrow at 7:05. The Moon, 2 days before new, will rise at 7:01 tomorrow morning.
We are exactly one month from our total solar eclipse this year, so I hope you’ve gotten your eclipse glasses or whatever else you need to safely view the Sun, or make plans to drive to the path of totality. This weekend we have a time change, spring forward to daylight savings time. It’s something I don’t look forward to, because it pushes the darkness in the evening out one more hour later. Not only does the sunset later each night, but we mess with the clocks to make it even later. By the end of June and early July twilight doesn’t officially end until after midnight. Then we only get 4 1/2 hours of darkness anyway if the Moon wasn’t out.
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: 03/07/2024 – There’s a unicorn in there somewhere
This is Bob Moler with Ephemeris for Thursday, March 7th. Today the Sun will be up for 11 hours and 30 minutes, setting at 6:39, and it will rise tomorrow at 7:06. The Moon, 3 days before new, will rise at 6:35 tomorrow morning.
The constellation of Monoceros the unicorn is located in an area of sky to the left of Orion so it’s in the south at 8 pm, inside the Winter Triangle of stars, Betelgeuse in Orion; Sirius in the Great Dog, Canis Major; and Procyon in Canis Minor. If you don’t see anything there, it’s OK. Nobody sees real unicorns any more anyway. Are there any real unicorns? Anyway, there’s a great number of nebulae here in the Milky Way that runs through it, which unfortunately are too faint to be seen with amateur telescopes. However, it is a gold mine for amateur astronomers who are also astrophotographers using time exposures to record the faint nebulae here, including the famous Rosette Nebula!
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: 03/06/2024 – Where have the naked-eye planets wandered off to this week?
This is Ephemeris for Wednesday, March 6th. Today the Sun will be up for 11 hours and 27 minutes, setting at 6:37, and it will rise tomorrow at 7:08. The Moon, 3 days past last quarter, will rise at 6:03 tomorrow morning.
Let’s find out where the naked-eye planets have wandered off to this week, and see what planets are left. Saturn, and Mercury are gone, too close to the Sun to be seen. Jupiter will be in the west-southwest at 8 this evening. It will set at 11:25 pm in the west. Jupiter will be visible in the evening for only about another month or so. Venus, the morning star, will rise in the east-southeast at 6:23 am, but its brilliance is diminished by the bright twilight and its low position in the sky. It will be very low in the east-southeast at 6:45 am. Mars might be impossible to spot, being a bit to the right and above Venus. A pair of binoculars, at least, will be needed to spot it. It is about the width of the field of binoculars from Venus.
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: 03/05/2024 – Finding Gemini the twins
This is Ephemeris for Tuesday, March 5th. Today the Sun will be up for 11 hours and 24 minutes, setting at 6:36, and it will rise tomorrow at 7:10. The Moon, 2 days past last quarter, will rise at 5:22 tomorrow morning.
The constellation of Gemini the twins can be seen high in the south at 8 pm tonight. It’s located above and left of the constellation of Orion. The two brightest stars at the upper left of the constellation have the twin’s names. They are Castor, the one to the upper right and Pollux the brighter one to the lower left. I tend to see the constellation as the two lines of stars from Castor and Pollux running down toward Orion as a silhouette of these two boys standing together. Others see them as two stick figures. At the bottom of the line of stars emanating from Castor, what I consider Castor’s foot, is a lovely star cluster which is visible in binoculars as a little fuzzy spot, but a telescope will show a great number of stars here called Messier 35 or simply M35.
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: 03/04/2024 – The evening skies are a-changing
This is Ephemeris for Monday, March 4th. Today the Sun will be up for 11 hours and 21 minutes, setting at 6:35, and it will rise tomorrow at 7:12. The Moon, 1 day past last quarter, will rise at 4:30 tomorrow morning.
Tonight at 8 pm Orion is in the south. This will be the last month that we will be able to enjoy Orion in the evening sky, because by month’s end he will begin to dip low in the west in the evening twilight. Even though it’s not quite spring, the central constellation of that season, Leo the lion, is already rising in the east. It has cleared the horizon at 8 this evening. The backwards question mark of Leo’s head, mane and front part of his body is easily spotted in the east now with the bright star Regulus at the bottom. The Big Dipper is in the northeast, also rising higher, and signaling via the Anishinaabek constellation there of the Fisher Star, announcing the maple sugaring season.
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
Looking to the east-southeast at 8 pm we look at three star groups or constellations. From left to right we have the Big Dipper and the Fisher Star in the northeast. Centered in the east we have Leo the lion. And on the right, just west of south, we have Orion the central winter constellation. Click or tap on the image to enlarge it. Credit: Stellarium, and using LibreOffice Draw, and GIMP.
Ephemeris: 03/01/2024 – Mr. Eclipse to give a presentation about April’s Total Solar Eclipse
This is Ephemeris for Friday, March 1st. Today the Sun will be up for 11 hours and 11 minutes, setting at 6:31, and it will rise tomorrow at 7:17. The Moon, 2 days before last quarter, will rise at 1:09 tomorrow morning.
Tonight’s meeting of the Grand Traverse Astronomical Society will start at a special time, 7 pm, at Northwestern Michigan College’s Rogers Observatory, because we will join the Kalamazoo Astronomical Society via Zoom for a talk by Fred Espenak formerly of NASA. He is known as Mr. Eclipse and of course he will be talking about the April 8th total solar eclipse. Fred Espenak has been responsible for NASA’s eclipse website through the 2017 total solar eclipse. He’s chased the shadow of the Moon around the world. Now retired, he hosts two websites. One of which is mreclipse.com. The observatory is located south of Traverse City on Birmley Road between Garfield and Keystone roads.
You may also join the Kalamazoo Astronomical Society meeting directly: Follow this link to register for Zoom. They have room for 500 people on Zoom, and they’d like to max that out!
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: 02/29/2024 – Previewing March Skies
This is Bob Moler with Ephemeris for Thursday, February 29th, the Leap Day or intercalary day. Today the Sun will be up for 11 hours and 8 minutes, setting at 6:30, and it will rise tomorrow at 7:19. The Moon, 3 days before last quarter, will rise at 11:59 this evening.
Let’s look at the skies for the month of March. The Sun will pass the celestial equator as the promising season of spring will begin. Daylight hours in the Interlochen/Traverse City area and will increase from 11 hours and 11 minutes Tomorrow to 12 hours 45 minutes on the 31st. The altitude, or angle, of the Sun above the southern horizon at local noon will be 38 degrees tomorrow and will ascend to nearly 50 degrees on the 31st. Spring will start on the 19th at 11:07 p.m. Part of the fault for that early date is the switch to daylight saving time this early in the year a while back. The Gregorian calendar reform of 1582 will keep the vernal equinox from falling much further back. So spring will come a bit early this year, calendar-wise.
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
March Evening Star Chart
The planets and stars are plotted for the 15th at 10 p.m. EDT in the evening and 6 a.m. for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian. (An hour and 45 minutes behind our Daylight Saving Time meridian during EDT). To duplicate the star positions on a planisphere (rotating star finder) you may have to set it to 45 minutes or 1 hour 45 minutes earlier than your current time.
Note the chart times of 10 p.m. and 6 a.m. are for the 15th. For each week before the 15th, add ½ hour (28 minutes if you’re picky). For each week after the 15th, subtract ½ hour. For planet positions on dates other than the 15th, check the Wednesday planet posts on this blog.
March 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, and
- Extend it as a spike to Spica.
- The Summer Triangle appears in red.
Twilight Limits, Nautical and Astronomical
| EST | |||||||
| Morning | Twilight | Evening | Twilight | Dark | Night | Moon | |
| Date | Astro. | Nautical | Nautical | Astro. | Start | End | Illum. |
| 2024-03-01 | 5h43m | 6h17m | 19h37m | 20h11m | 20h11m | – | 0.65 |
| 2024-03-02 | 5h41m | 6h15m | 19h38m | 20h12m | 20h12m | 1h09m | 0.55 |
| 2024-03-03 | 5h40m | 6h13m | 19h39m | 20h13m | 20h13m | 2h20m | 0.44 |
| 2024-03-04 | 5h38m | 6h12m | 19h41m | 20h15m | 20h15m | 3h28m | 0.34 |
| 2024-03-05 | 5h36m | 6h10m | 19h42m | 20h16m | 20h16m | 4h30m | 0.23 |
| 2024-03-06 | 5h34m | 6h08m | 19h43m | 20h17m | 20h17m | 5h22m | 0.14 |
| 2024-03-07 | 5h32m | 6h06m | 19h45m | 20h19m | 20h19m | 5h32m | 0.07 |
| 2024-03-08 | 5h30m | 6h05m | 19h46m | 20h20m | 20h20m | 5h30m | 0.02 |
| 2024-03-09 | 5h29m | 6h03m | 19h47m | 20h21m | 20h21m | 5h29m | 0.00 |
| EDT | |||||||
| 2024-03-10 | 6h27m | 7h01m | 20h48m | 21h23m | 21h23m | 6h27m | 0.01 |
| 2024-03-11 | 6h25m | 6h59m | 20h50m | 21h24m | 21h45m | 6h25m | 0.05 |
| 2024-03-12 | 6h23m | 6h57m | 20h51m | 21h25m | 23h07m | 6h23m | 0.12 |
| 2024-03-13 | 6h21m | 6h55m | 20h52m | 21h27m | – | 6h21m | 0.20 |
| 2024-03-14 | 6h19m | 6h54m | 20h54m | 21h28m | 0h29m | 6h19m | 0.30 |
| 2024-03-15 | 6h17m | 6h52m | 20h55m | 21h30m | 1h48m | 6h17m | 0.40 |
| 2024-03-16 | 6h15m | 6h50m | 20h56m | 21h31m | 3h02m | 6h15m | 0.51 |
| 2024-03-17 | 6h13m | 6h48m | 20h58m | 21h32m | 4h07m | 6h13m | 0.61 |
| 2024-03-18 | 6h11m | 6h46m | 20h59m | 21h34m | 5h00m | 6h11m | 0.70 |
| 2024-03-19 | 6h09m | 6h44m | 21h00m | 21h35m | 5h41m | 6h09m | 0.78 |
| 2024-03-20 | 6h07m | 6h42m | 21h02m | 21h37m | – | – | 0.86 |
| 2024-03-21 | 6h05m | 6h40m | 21h03m | 21h38m | – | – | 0.92 |
| 2024-03-22 | 6h03m | 6h38m | 21h04m | 21h40m | – | – | 0.96 |
| 2024-03-23 | 6h01m | 6h36m | 21h06m | 21h41m | – | – | 0.99 |
| 2024-03-24 | 5h59m | 6h34m | 21h07m | 21h43m | – | – | 1.00 |
| 2024-03-25 | 5h57m | 6h32m | 21h08m | 21h44m | – | – | 0.99 |
| 2024-03-26 | 5h55m | 6h30m | 21h10m | 21h46m | – | – | 0.97 |
| 2024-03-27 | 5h53m | 6h28m | 21h11m | 21h47m | 21h47m | 22h51m | 0.92 |
| 2024-03-28 | 5h50m | 6h26m | 21h13m | 21h49m | 21h49m | 0h00m | 0.86 |
| 2024-03-29 | 5h48m | 6h24m | 21h14m | 21h50m | 21h50m | – | 0.79 |
| 2024-03-30 | 5h46m | 6h22m | 21h15m | 21h52m | 21h52m | 1h10m | 0.70 |
| 2024-03-31 | 5h44m | 6h20m | 21h17m | 21h53m | 21h53m | 2h18m | 0.60 |
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/2019/09/27/
NASA Calendar of Planetary Events
Date Time EST Event
Mar 1 Fr Venus: 24.3° W
3 Su 3:16 am Moon-Antares: .4° S
3 Su 10:24 am Last Quarter
4 Mo 9:03 pm Moon South Dec.: 28.5° S
7 Th 11:59 pm Moon-Mars: 3.5° N
8 Fr 12:01 pm Moon-Venus: 3.2° N
Time EDT
10 Su 2:06 am Moon Perigee: 356900 km
10 Su 4:00 am New Moon
11 Mo 9:18 pm Moon Ascending Node
13 We 9:01 pm Moon-Jupiter: 3.6° S
14 Th 10:54 pm Moon-Pleiades: .4° N
17 Su 12:11 am First Quarter
17 Su 6:31 am Neptune Conjunction
17 Su 10:45 am Moon North Dec.: 28.5° N
19 Tu 2:44 am Moon-Pollux: 1.6° N
19 Tu 11:07 pm Vernal Equinox
20 We 4:03 am Moon-Beehive: 3.8° S
21 Th 6:06 pm Venus-Saturn: .3° N
23 Sa 11:44 am Moon Apogee: 406300 km
24 Su 5:59 pm Mercury Elongation: 18.7° E
25 Mo 3:00 am Full Moon
25 Mo 3:13 am Penumbral Lunar Eclipse
26 Tu 12:07 am Moon Descending Node
26 Tu 3:40 pm Moon-Spica: 1.6° S
30 Sa 10:24 am Moon-Antares: .3° S
Apr 1 Mo Venus: 16.8° W
All event times are given for UTC-5:00: Eastern Standard Time before the 10th or UTC-4:00 Daylight Saving Time thereafter.
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.
Note that the site is now kept up for archival purposes. Fred Espenak retired from NASA several years ago and has his own site, AstroPixels, which contain the same information: http://astropixels.com/almanac/almanac.html.
Sun and Moon Rising and Setting Events
LU Ephemeris of Sky Events for Interlochen/TC
March, 2024 Local time zone: EST
+-----------------------------------------------------------------------+
| DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM |
| | RISE SET HOURS | END START |PHASE SET** TIME FRACTN|
+=======================================================================+
|Fri 1| 07:19a 06:31p 11:11 | 07:34p 06:16a | Rise 01:09a 66%|
|Sat 2| 07:17a 06:32p 11:15 | 07:35p 06:14a | Rise 02:19a 57%|
+------+-----------------------+----------------+-----------------------+
|Sun 3| 07:15a 06:34p 11:18 | 07:37p 06:12a |L Qtr Rise 03:28a 46%|
|Mon 4| 07:14a 06:35p 11:21 | 07:38p 06:11a | Rise 04:30a 36%|
|Tue 5| 07:12a 06:36p 11:24 | 07:39p 06:09a | Rise 05:22a 26%|
|Wed 6| 07:10a 06:37p 11:27 | 07:41p 06:07a | Rise 06:03a 16%|
|Thu 7| 07:08a 06:39p 11:30 | 07:42p 06:05a | Rise 06:35a 8%|
|Fri 8| 07:06a 06:40p 11:33 | 07:43p 06:04a | Rise 07:01a 3%|
|Sat 9| 07:05a 06:41p 11:36 | 07:44p 06:02a | Rise 07:24a 0%|
+------+-----------------------+----------------+-----------------------+
| EDT | Time Change | | |
|Sun 10| 08:03a 07:43p 11:39 | 08:46p 07:00a |New Set 08:22p 1%|
|Mon 11| 08:01a 07:44p 11:43 | 08:47p 06:58a | Set 09:44p 4%|
|Tue 12| 07:59a 07:45p 11:46 | 08:48p 06:56a | Set 11:07p 10%|
|Wed 13| 07:57a 07:47p 11:49 | 08:50p 06:54a | Set 12:28a 18%|
|Thu 14| 07:55a 07:48p 11:52 | 08:51p 06:53a | Set 01:47a 28%|
|Fri 15| 07:54a 07:49p 11:55 | 08:52p 06:51a | Set 03:01a 38%|
|Sat 16| 07:52a 07:50p 11:58 | 08:54p 06:49a | Set 04:06a 48%|
+------+-----------------------+----------------+-----------------------+
|Sun 17| 07:50a 07:52p 12:01 | 08:55p 06:47a |F Qtr Set 04:59a 58%|
|Mon 18| 07:48a 07:53p 12:04 | 08:56p 06:45a | Set 05:41a 68%|
|Tue 19| 07:46a 07:54p 12:08 | 08:58p 06:43a | Set 06:13a 77%|
|Wed 20| 07:44a 07:56p 12:11 | 08:59p 06:41a | Set 06:38a 84%|
|Thu 21| 07:43a 07:57p 12:14 | 09:00p 06:39a | Set 06:59a 91%|
|Fri 22| 07:41a 07:58p 12:17 | 09:02p 06:37a | Set 07:16a 95%|
|Sat 23| 07:39a 07:59p 12:20 | 09:03p 06:35a | Set 07:32a 98%|
+------+-----------------------+----------------+-----------------------+
|Sun 24| 07:37a 08:01p 12:23 | 09:04p 06:33a | Set 07:48a 100%|
|Mon 25| 07:35a 08:02p 12:26 | 09:06p 06:31a |Full Rise 08:39p 100%|
|Tue 26| 07:33a 08:03p 12:29 | 09:07p 06:29a | Rise 09:44p 97%|
|Wed 27| 07:31a 08:04p 12:33 | 09:09p 06:27a | Rise 10:50p 93%|
|Thu 28| 07:30a 08:06p 12:36 | 09:10p 06:25a | Rise 11:59p 88%|
|Fri 29| 07:28a 08:07p 12:39 | 09:11p 06:23a | Rise 01:09a 80%|
|Sat 30| 07:26a 08:08p 12:42 | 09:13p 06:21a | Rise 02:18a 72%|
+------+-----------------------+----------------+-----------------------+
|Sun 31| 07:24a 08:09p 12:45 | 09:14p 06:19a | Rise 03:21a 62%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset
Created using my LookingUp for DOS output as text.
Ephemeris: 02/28/2024 – Where have the naked-eye planets wandered off to this week?
This is Ephemeris for Wednesday, February 28th. Today the Sun will be up for 11 hours and 5 minutes, setting at 6:28, and it will rise tomorrow at 7:21. The Moon, halfway from full to last quarter, will rise at 10:52 this evening.
Let’s find out where the naked-eye planets have wandered off to this week, and see what planets are left to see. Saturn, and Mercury are gone, both actually in conjunction with the Sun today. Jupiter will be in the west-southwest at 8 this evening. It will set at 11:47 pm in the west. Jupiter will be visible in the evening for only about two more months. Venus, the morning star, will rise in the east-southeast at 6:27 am, but its brilliance is diminished by the bright twilight and its low position in the sky. It will be very low in the east-southeast at 7 am. Mars might be impossible to spot, being a bit to the right and above Venus. A pair of binoculars, at least, will be needed to spot it in the morning twilight.
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
Jupiter’s moon Io will pass behind (be occulted by) the planet at 8:17 pm EST. It will reappear at 11:39 pm away from the planet because until then it’ll still be in Jupiter’s shadow.
The ” symbol means seconds of arc (1/3600th of a degree). Created using Cartes du Ciel (Sky Charts) and GIMP.
Ephemeris: 02/27/2024 – Thursday is the Intercalary Day
This is Bob Moler with Ephemeris for Tuesday, February 27th. Today the Sun will be up for 11 hours and 2 minutes, setting at 6:27, and it will rise tomorrow at 7:22. The Moon, 3 days past full, will rise at 9:47 this evening.
Thursday we’re going to have one of those special days that only occur once every 4 years making this a leap year. It’s the intercalary day that compensates for that fact that the Earth takes 365 and a bit short of a quarter day to orbit the sun. That orbit is a year, and those quarter days are accumulated and added as the last day of February in years divisible by 4. The Gregorian reform makes a slight adjustment to most century years, making century years not divisible by 400 ordinary years to keep the calendar in sync with the seasons. The Romans, from who we’ve gotten our calendar considered the month of February as unlucky, and so they shortened it most years to 28 days. Enjoy your extra day Thursday.
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
No calendar is perfect. The average year of the Julian Calendar is 11 minutes and 14 seconds longer than the actual seasonal year which it is trying to model. By the time of the papacy of Pope Gregory XIII from 1572 to 1585 CE the error in the Julian calendar versus the actual seasons had grown to 10 days since the Julian Calendar was established 16 centuries before. The reason the Church was concerned was that Easter was slowly advancing toward summer, and Easter is a more important feast than Christmas, but is related to the Jewish Feast of Passover. I’ll discuss the formula for determining Easter as we get closer to it. However, the Gregorian calendar reform came in two parts: Ten days were dropped from the calendar between October 4th and 15th in the year 1582 and after that the every four year leap day rule, that is years evenly divided by 4, was modified so that on century years, that is years ending in 00, but not divisible by 400, became ordinary years, that is no leap days, this will keep the calendar in sync with the seasons for several millennia. This calendar reform occurring after the Reformation meant that only the Catholic countries adopted it. It took almost until the present day for everyone to adopt it. For ecclesiastical purposes the Orthodox Churches still used the Julian Calendar.
Ephemeris: 02/26/2024 – The angle of the rising and setting planets from the Sun vary with the seasons
This is Bob Moler with Ephemeris for Monday, February 26th. Today the Sun will be up for 10 hours and 59 minutes, setting at 6:25, and it will rise tomorrow at 7:24. The Moon, 2 days past full, will rise at 8:44 this evening.
In late winter and early spring dark skies return within a few days after the full Moon. Indeed, this is the first day after the full moon, which was on Saturday morning, that we have dark skies. Well for 40 minutes before the Moon rises. This is because the ecliptic which is the Sun’s path in the sky is as close to vertical as it can get for us. It shows planets near the Sun and the area of the full moon as steeply inclined to the horizon as possible. Twelve years ago this month when my wife and I were on a Hawaiian cruise, I was aboard ship looking at the sky after sunset and was amazed to see Jupiter and Venus* vertically aligned in the west. It was because we were located around the Tropic of Cancer and near the equinox, so the ecliptic was actually vertical after sunset. It was quite a jolt to see that. So this time of year we can see planets close to the sun at sunset and the moon to go away after full rapidly.
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.
* On the broadcast I said Jupiter and Saturn, relying on my memory. As can be seen below, it was Jupiter and Venus.
Addendum
Bob Moler's Ephemeris Blog 
