Bob Moler's Ephemeris Blog

This is Ephemeris for Tuesday, December 1st. Today the Sun will be up for 9 hours and 2 minutes, setting at 5:03, and it will rise tomorrow at 8:01. The Moon, 1 day past full, will rise at 6:02 this evening.

Let’s look at December skies. We are now in the holiday season and about to celebrate the southernmost travel of the Sun in the sky and its return northward. So there is not much change in sunrise and sunset times. The Sun will stop its travel south, the winter solstice, on the 21st at 5:02 am. It will make that day the shortest day in terms of daylight hours. However, the earliest sunset will occur on the 9th. The Geminid meteor shower will reach its peak on the evening of the 13th, near new moon. Also in the evening on the 21st Jupiter and Saturn will be in conjunction and will be easily visible in the same binocular or low power telescope field. This month starts out with a surprisingly active Sun at the start of a new sunspot cycle.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

December Evening Star Chart

Star Chart for December 2020 (7 p.m. EST December 15, 2019). Click on image to enlarge. Created using my LookingUp program. Click on image to enlarge.
Credit my LookingUp program.

The planets and stars are plotted for the 15th at 7 pm EST (two hours earlier this year to include Jupiter and Saturn) 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, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT).

December Morning Star Chart

Star Chart for December mornings 2020 (6 a.m. EST December 15, 2020). Click on image to enlarge. Created using my LookingUp program. Credit my LookingUp program.

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.
• The Summer Triangle is in red.
• GemR on the star charts is the radiant of the Geminid meteor shower which peaks on the evening of the 13th.

Twilight Limits, Nautical and Astronomical

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
Dec 1  Tu            Venus: 27.5° W
    1  Tu  02:46 am  Moon Ascending Node
    2  We  08:22 pm  Moon North Dec.: 24.9° N
    4  Fr  08:10 pm  Moon-Beehive: 2.5° S
    7  Mo  07:37 pm  Last Quarter
   12  Sa  03:40 pm  Moon-Venus: 0.8° S
   12  Sa  03:42 pm  Moon Perigee: 361800 km
   13  Su  07:50 pm  Geminid Meteor Shower: ZHR = 120
   14  Mo  06:03 am  Moon Descending Node
   14  Mo  11:15 am  Total Solar Eclipse
                          (Pacific, S America, Atlantic)
   14  Mo  11:17 am  New Moon
   15  Tu  05:23 pm  Moon South Dec.: 24.9° S
   16  We  11:28 pm  Moon-Jupiter: 3° N
   17  Th  12:25 am  Moon-Saturn: 3.1° N
   19  Sa  09:56 pm  Mercury Superior Solar Conjunction
   21  Mo  05:02 am  Winter Solstice
   21  Mo  06:41 pm  First Quarter
   22  Tu  04:00 am  Ursid Meteor Shower: ZHR = 10
   22  Tu  04:35 am  Jupiter-Saturn: 0.1° N
   23  We  09:48 am  Venus-Antares: 5.6° N
   24  Th  11:32 am  Moon Apogee: 405000 km
   28  Mo  10:03 am  Moon Ascending Node
   29  Tu  10:28 pm  Full Moon
   30  We  02:53 am  Moon North Dec.: 24.9° N

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
December, 2020    Local time zone: EST
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Tue  1| 08:00a  05:03p  09:02 | 06:12p  06:51a |      Rise 06:02p   98%|
|Wed  2| 08:01a  05:03p  09:01 | 06:12p  06:52a |      Rise 06:51p   94%|
|Thu  3| 08:02a  05:02p  09:00 | 06:12p  06:53a |      Rise 07:48p   88%|
|Fri  4| 08:03a  05:02p  08:58 | 06:12p  06:53a |      Rise 08:52p   80%|
|Sat  5| 08:04a  05:02p  08:57 | 06:12p  06:54a |      Rise 10:00p   71%|
+------+-----------------------+----------------+-----------------------+
|Sun  6| 08:05a  05:02p  08:56 | 06:12p  06:55a |      Rise 11:12p   61%|
|Mon  7| 08:06a  05:02p  08:55 | 06:12p  06:56a |L Qtr Rise 12:25a   50%|
|Tue  8| 08:07a  05:02p  08:54 | 06:12p  06:57a |      Rise 01:39a   39%|
|Wed  9| 08:08a  05:02p  08:53 | 06:12p  06:58a |      Rise 02:55a   28%|
|Thu 10| 08:09a  05:02p  08:52 | 06:12p  06:59a |      Rise 04:13a   18%|
|Fri 11| 08:10a  05:02p  08:51 | 06:12p  07:00a |      Rise 05:33a   10%|
|Sat 12| 08:11a  05:02p  08:51 | 06:12p  07:00a |      Rise 06:53a    4%|
+------+-----------------------+----------------+-----------------------+
|Sun 13| 08:12a  05:02p  08:50 | 06:13p  07:01a |      Rise 08:11a    1%|
|Mon 14| 08:12a  05:02p  08:49 | 06:13p  07:02a |New   Set  05:06p    0%|
|Tue 15| 08:13a  05:02p  08:49 | 06:13p  07:02a |      Set  06:03p    2%|
|Wed 16| 08:14a  05:03p  08:48 | 06:13p  07:03a |      Set  07:09p    7%|
|Thu 17| 08:14a  05:03p  08:48 | 06:14p  07:04a |      Set  08:18p   14%|
|Fri 18| 08:15a  05:03p  08:48 | 06:14p  07:04a |      Set  09:29p   22%|
|Sat 19| 08:16a  05:04p  08:48 | 06:15p  07:05a |      Set  10:37p   31%|
+------+-----------------------+----------------+-----------------------+
|Sun 20| 08:16a  05:04p  08:48 | 06:15p  07:05a |      Set  11:42p   40%|
|Mon 21| 08:17a  05:05p  08:48 | 06:16p  07:06a |F Qtr Set  12:45a   50%|
|Tue 22| 08:17a  05:05p  08:48 | 06:16p  07:06a |      Set  01:47a   60%|
|Wed 23| 08:18a  05:06p  08:48 | 06:17p  07:07a |      Set  02:49a   69%|
|Thu 24| 08:18a  05:07p  08:48 | 06:17p  07:07a |      Set  03:50a   77%|
|Fri 25| 08:18a  05:07p  08:48 | 06:18p  07:08a |      Set  04:53a   84%|
|Sat 26| 08:19a  05:08p  08:49 | 06:19p  07:08a |      Set  05:57a   91%|
+------+-----------------------+----------------+-----------------------+
|Sun 27| 08:19a  05:09p  08:49 | 06:19p  07:08a |      Set  07:00a   96%|
|Mon 28| 08:19a  05:09p  08:50 | 06:20p  07:09a |      Set  08:01a   99%|
|Tue 29| 08:19a  05:10p  08:50 | 06:21p  07:09a |Full  Rise 04:45p  100%|
|Wed 30| 08:19a  05:11p  08:51 | 06:21p  07:09a |      Rise 05:40p   99%|
|Thu 31| 08:20a  05:12p  08:52 | 06:22p  07:09a |      Rise 06:43p   96%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

This is Bob Moler with Ephemeris for Monday, October 5th. Today the Sun will be up for 11 hours and 28 minutes, setting at 7:14, and it will rise tomorrow at 7:47. The Moon, half way from full to last quarter, will rise at 9:15 this evening.

Sixty three years ago yesterday the space age began with the Soviet Union’s launching of the first artificial Earth satellite Sputnik 1. the name Sputnik means fellow traveler or traveling companion. I was a junior in high school at the time and already into astronomy and was well aware of the United States own Vanguard satellite program and preparations for amateur astronomers to track it from the ground. I was watching TV that night when the news broke that the Russians launched a satellite and played the beep-beep-beep transmitted by Sputnik and a white dot moving across the screen, supposedly the satellite. It caused a great deal of soul searching by the public about our science and educational programs.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

This is Bob Moler with Ephemeris for Monday, May 4th. Today the Sun will be up for 14 hours and 24 minutes, setting at 8:52, and it will rise tomorrow at 6:26. The Moon, 3 days before full, will set at 5:47 tomorrow morning.

May is a month of preparation for the space community. The Mars 2020 Rover, now named Endurance is getting packed up and balanced in preparation to be loaded into the sky crane and aeroshell, part of the cruise stage for its trip to Mars. It will employ the same landing technique as its predecessor, Curiosity which landed 9 years before in 2012. The launch is scheduled for July 17th to land on February 18th next year. It will deploy a small helicopter as a demonstration. It has many of the tools as Curiosity plus new ones and will cache rocks for future return to the Earth for further analysis. Hopefully by month’s end two NASA astronauts will launch on a Falcon 9 from US soil to the International Space Station.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Mars 2020 Rover “Endurance” destined for the martian crater Jezero. Credit NASA.

Mars Helicopter “Ingenuity” after deployment. Delta of ancient river that flowed into a lake in the Jezero crater. Credit NASA.

Delta of ancient river that flowed into a lake in the Jezero crater. Credit NASA.

Crew Dragon docking to the International Space Station during the Demo 1 flight. Credit NASA.

Ephemeris for Friday, August 16th. Today the Sun will be up for 14 hours and 1 minute, setting at 8:47, and it will rise tomorrow at 6:47. The Moon, 1 day past full, will rise at 9:44 this evening.

Members of the Grand Traverse Astronomical Society will be in Downtown Traverse City for Friday Night Line again this evening. We might get a glimpse of the Moon later tonight. Speaking of the Moon, the rocks brought back from the Moon by the Apollo astronauts turn out to be very similar to earthly rocks. This gave rise to the most popular theory of how the Moon formed. A second planet was born in the Earth’s orbit lazily orbiting at a point 60 degrees ahead or behind the Earth itself. Perturbations possibly by Venus caused it to crash into the Earth with a glancing blow sending debris into orbit of the Earth to become the Moon. It explains the similarity of the rocks of the Earth and and those brought back from the Moon.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

A progression of how the Moon may have fomed by a small protoplanet crashing into the Earth. Credit: Brian Koberlein