Bob Moler's Ephemeris Blog

This is Ephemeris for Tuesday, March 31st. Today the Sun will be up for 12 hours and 43 minutes, setting at 8:09, and it will rise tomorrow at 7:23. The Moon, 1 day before full, will set at 7:00 tomorrow morning.

The 4th month of the year begins tomorrow. Daylight hours in the Interlochen/Traverse City area will increase from 12 hours and 47 minutes tomorrow to 14 hours and 12 minutes on April 30th. The altitude, or angle, of the Sun above the southern horizon at local noon will be 50 degrees tomorrow and will ascend to 60 degrees on April 30th. The altitude of the Sun in the Straits area will be a degree lower, but their daylight hours will be a bit longer. The actual time of local apparent noon, when the Sun passes due south at mid-month, will be about 1:42 PM. The Lyrid meteor shower will reach its peak on the afternoon of the 22nd. So the hours after 2 or 3 AM on the 22nd and 23rd will be the best time to see them in dark skies.

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

April Evening Star Chart

The planets and stars are plotted for the 15th at 10 PM EDT in the evening and 5 AM for the morning chart. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian. (An hour 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 one hour 45 minutes (Daylight Time) earlier than the current time.

Note the chart times of 10 PM and 6 AM are for the 15th and 16th. For each week before these dates, add ½ hour (28 minutes if you’re picky). For each week after, subtract ½ hour. Planet positions on dates other than the 15/16th can be found in the Wednesday planet posts on this blog.

April Morning Star Chart

Twilight Limits, Nautical and Astronomical

			EDT
	Morning	Twilight	Evening	Twilight	Dark	Night	Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2026-04-01	5h43m	6h19m	21h17m	21h54m	–	–	100%
2026-04-02	5h41m	6h17m	21h19m	21h56m	–	–	99%
2026-04-03	5h39m	6h15m	21h20m	21h57m	21h57m	22h23m	96%
2026-04-04	5h36m	6h13m	21h22m	21h59m	21h59m	23h30m	91%
2026-04-05	5h34m	6h11m	21h23m	22h00m	22h00m	–	85%
2026-04-06	5h32m	6h09m	21h24m	22h02m	22h02m	0h36m	77%
2026-04-07	5h30m	6h07m	21h26m	22h04m	22h04m	1h38m	69%
2026-04-08	5h28m	6h05m	21h27m	22h05m	22h05m	2h34m	60%
2026-04-09	5h25m	6h03m	21h29m	22h07m	22h07m	3h20m	50%
2026-04-10	5h23m	6h02m	21h30m	22h08m	22h08m	3h58m	41%
2026-04-11	5h21m	6h00m	21h32m	22h10m	22h10m	4h29m	31%
2026-04-12	5h19m	5h58m	21h33m	22h12m	22h12m	4h54m	22%
2026-04-13	5h17m	5h56m	21h35m	22h14m	22h14m	5h16m	14%
2026-04-14	5h14m	5h54m	21h36m	22h15m	22h15m	5h14m	7%
2026-04-15	5h12m	5h52m	21h38m	22h17m	22h17m	5h12m	2%
2026-04-16	5h10m	5h50m	21h39m	22h19m	22h19m	5h10m	0%
2026-04-17	5h08m	5h48m	21h41m	22h21m	22h21m	5h08m	1%
2026-04-18	5h06m	5h46m	21h42m	22h22m	22h43m	5h06m	4%
2026-04-19	5h03m	5h44m	21h44m	22h24m	–	5h03m	11%
2026-04-20	5h01m	5h42m	21h45m	22h26m	0h06m	5h01m	19%
2026-04-21	4h59m	5h40m	21h47m	22h28m	1h20m	4h59m	29%
2026-04-22	4h57m	5h38m	21h48m	22h30m	2h21m	4h57m	40%
2026-04-23	4h54m	5h36m	21h50m	22h31m	3h08m	4h54m	51%
2026-04-24	4h52m	5h34m	21h51m	22h33m	3h42m	4h52m	62%
2026-04-25	4h50m	5h32m	21h53m	22h35m	4h09m	4h50m	72%
2026-04-26	4h48m	5h30m	21h54m	22h37m	4h30m	4h48m	81%
2026-04-27	4h46m	5h29m	21h56m	22h39m	–	–	88%
2026-04-28	4h43m	5h27m	21h57m	22h41m	–	–	94%
2026-04-29	4h41m	5h25m	21h59m	22h43m	–	–	98%
2026-04-30	4h39m	5h23m	22h01m	22h45m	–	–	100%

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

Apr  1  We            Venus: 20.5° E
     1  We  10:12 PM  Full Moon
     2  Th   9:32 PM  Moon-Spica: 1.9° N
     3  Fr   6:59 PM  Mercury Elongation: 27.8° W
     6  Mo   3:21 PM  Moon-Antares: 0.7° N
     7  Tu   4:32 AM  Moon Apogee: 405000 km
     8  We   1:01 AM  Moon South Dec.: 28.3° S
    10  Fr  12:52 AM  Last Quarter
    13  Mo   7:43 PM  Moon Ascending Node
    15  We   8:45 PM  Moon-Mars: 3.8° S
    17  Fr   7:52 AM  New Moon
    19  Su   2:57 AM  Moon Perigee: 361600 km
    19  Su   4:48 AM  Moon-Venus: 4.7° S
    19  Su  12:28 PM  Moon-Pleiades: 1° S
    19  Su   3:04 PM  Mars-Saturn: 1.2° N
    20  Mo   5:41 AM  Mercury-Saturn: 0.5° N
    20  Mo   6:15 PM  Mercury-Mars: 1.7° N
    21  Tu   7:12 AM  Moon North Dec.: 28.2° N
    22  We   3:02 PM  Lyrid Shower: ZHR = 20
    22  We   6:06 PM  Moon-Jupiter: 3.6° S
    23  Th  10:32 PM  First Quarter
    24  Fr  12:15 AM  Venus-Pleiades: 3.5° S
    24  Fr   3:46 AM  Moon-Beehive: 1.1° S
    25  Sa   8:37 PM  Moon-Regulus: 0.2° S (Occultation possibility)
    26  Su  10:36 AM  Moon Descending Node
    30  Th   4:17 AM  Moon-Spica: 2° N
May  1  Fr            Venus: 27.8° E

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
April, 2026    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Wed  1| 07:23a  08:10p  12:47 | 09:15p  06:18a |Full  Rise 08:06p  100%|
|Thu  2| 07:21a  08:11p  12:50 | 09:16p  06:16a |      Rise 09:14p   99%|
|Fri  3| 07:19a  08:13p  12:53 | 09:18p  06:14a |      Rise 10:22p   96%|
|Sat  4| 07:17a  08:14p  12:56 | 09:19p  06:12a |      Rise 11:30p   92%|
+------+-----------------------+----------------+-----------------------+
|Sun  5| 07:16a  08:15p  12:59 | 09:21p  06:10a |      Rise 12:36a   86%|
|Mon  6| 07:14a  08:16p  13:02 | 09:22p  06:08a |      Rise 01:38a   79%|
|Tue  7| 07:12a  08:18p  13:05 | 09:23p  06:06a |      Rise 02:33a   70%|
|Wed  8| 07:10a  08:19p  13:08 | 09:25p  06:04a |      Rise 03:20a   61%|
|Thu  9| 07:08a  08:20p  13:11 | 09:26p  06:02a |      Rise 03:58a   52%|
|Fri 10| 07:07a  08:21p  13:14 | 09:28p  06:00a |L Qtr Rise 04:29a   42%|
|Sat 11| 07:05a  08:23p  13:17 | 09:29p  05:58a |      Rise 04:54a   33%|
+------+-----------------------+----------------+-----------------------+
|Sun 12| 07:03a  08:24p  13:20 | 09:31p  05:57a |      Rise 05:16a   23%|
|Mon 13| 07:01a  08:25p  13:23 | 09:32p  05:55a |      Rise 05:35a   15%|
|Tue 14| 07:00a  08:26p  13:26 | 09:34p  05:53a |      Rise 05:55a    8%|
|Wed 15| 06:58a  08:28p  13:29 | 09:35p  05:51a |      Rise 06:15a    3%|
|Thu 16| 06:56a  08:29p  13:32 | 09:37p  05:49a |      Rise 06:38a    0%|
|Fri 17| 06:54a  08:30p  13:35 | 09:38p  05:47a |New   Set  09:17p    1%|
|Sat 18| 06:53a  08:31p  13:38 | 09:40p  05:45a |      Set  10:42p    3%|
+------+-----------------------+----------------+-----------------------+
|Sun 19| 06:51a  08:33p  13:41 | 09:41p  05:43a |      Set  12:05a    9%|
|Mon 20| 06:49a  08:34p  13:44 | 09:43p  05:41a |      Set  01:20a   17%|
|Tue 21| 06:48a  08:35p  13:47 | 09:44p  05:39a |      Set  02:21a   27%|
|Wed 22| 06:46a  08:36p  13:50 | 09:46p  05:37a |      Set  03:07a   38%|
|Thu 23| 06:45a  08:37p  13:52 | 09:47p  05:35a |F Qtr Set  03:42a   49%|
|Fri 24| 06:43a  08:39p  13:55 | 09:49p  05:33a |      Set  04:08a   60%|
|Sat 25| 06:41a  08:40p  13:58 | 09:50p  05:31a |      Set  04:30a   70%|
+------+-----------------------+----------------+-----------------------+
|Sun 26| 06:40a  08:41p  14:01 | 09:52p  05:29a |      Set  04:49a   79%|
|Mon 27| 06:38a  08:42p  14:04 | 09:53p  05:28a |      Set  05:06a   87%|
|Tue 28| 06:37a  08:44p  14:07 | 09:55p  05:26a |      Set  05:24a   93%|
|Wed 29| 06:35a  08:45p  14:09 | 09:57p  05:24a |      Set  05:42a   97%|
|Thu 30| 06:34a  08:46p  14:12 | 09:58p  05:22a |      Set  06:03a   99%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise

Created using my LookingUp for MS-DOS app.