ALMANAC

Notes by George Gladfelter

05/08/2020

 

Changes may be shown in green or blue.

 

 

Meteor Shower Calendar (Best viewing after midnight looking east.  Dates vary from year to year.)

Dates (maximum)     Shower Name

Jan 1-5 (3-4)              Quadrantids

Jan 15 - Feb 8 (7-8)    Alpha Aurigids

Apr 19-24 (22)           April Lyrids

May 1-12 (5)              Eta Aquarids

June 10-21 (15)          June Lyrids

Jul 15 - Aug 15 (28)    Delta Aquarids

Aug 1-18 (12)             Perseids

Oct 17-26 (20)            Orionids

Nov 14-20 (17)           Leonids

Dec 4-16 (13-14)        Geminids

 

1. Click here for the data (world wide) on moon phases, solar and lunar eclipses, equinoxes and solstices, lunar perigee and apogee, lunar perihelion and aphelion, and various data for Mercury, Venus, Mars, Jupiter, and Saturn for 2020-2023.  Also available are detailed data on solar eclipses for 2020-2021. 
Note: Copies of previous editions should be discarded.

 

2. Click here for revised sunrise, sunset, and twilight times at the Journey Museum and Learning Center (JMLC) for 2020-2023.  For an explanation of the table, click here.

 

3. Click here for times of moonrise, moonset, and transits of the moon (as seen from JMLC) and also the percentage of the moon's disk that is illuminated, and the Moon's declination, at 9 PM MST for 2020-2023.  Note: rising and setting times of any celestial object are subject to uncertainty due to topology, and especially variations in atmospheric refraction.  Also, the calculations are specific to a single location and cannot be easily adapted to locations more than a few miles away; therefore, treat the tabulated times for moonrise and moonset as approximations.  The other times listed are not affected by refraction, but are specific to the observer's longitude or position. Only phenomena that will be visible (assuming no clouds) are listed.

 

4. The planets are best placed for observing from the Earth when farthest from the Sun.  For Mercury and Venus this is the time of greatest separation or elongation (they are not exactly the same), and for the others the time called opposition (this is the time when the planet's right ascension is 180 degrees away from the Sun's).  For a table of these times for 2018-2025 click here. Revised and extended 7/15/2018.

 

5. Click here for a table showing data at dusk, the middle of the night, and dawn for the sun, moon, and the five bright planets for each night 2020-2023.  If the moon, or a planet, is within five degrees of a planet, another line of data shows the visual separation of the pair.  Click here for an explanation of the table. Also, click here for times of rising, setting, and transit (marked "r", "s", or "t") of the sun, moon, and bright planets in 2020-2023.  Included are the times for morning and evening twilight (mt and et), the four phases of the moon, and the seasons (ME = March Equinox, JS = June Solstice, SE = September Equinox, DS = December Solstice).  Note: the rising and setting times are for the center of the sun, moon, or planet without correcting to the upper limb of the object; the twilight times are for when the sun is 15 degrees below the horizon - this is intermediate between nautical and astronomical twilight. Note well - this file is close to 150 pages long.

 

6. Click here for a table listing the transit times of twenty stars, as seen from JMLC, for 2020-2023. These data can be used easily to calculate approximate rising and setting times. Click here for an explanation of the table.

 

7. Click here for dates and times of Transits of Mercury 2016-2100.

 

8. Click here for a complete list of Lunar Occultations of bright planets and certain bright stars, and solar eclipses (2020-2023) with data for observers at the Journey Museum in Rapid City as appropriate. revised 05/03/2020.

 

9. Posted here is a text file giving the coefficients for apparent Right Ascension, Declination, Distance, and Horizontal Parallax of the Moon for 2020-2021. The distance is the true distance (light time not factored in) in kilometers.  The angular coordinates are in degrees.  Each quantity is to be computed as:

                quantity = A0 + A1x + A2x2 + ... + A5x5

                where x = h/24 with h = time in hours
thus,  0.0  <=  x  < +1.0.

The results for the angular quantities should agree very closely with the tabulated values in the Astronomical Almanac, and the distance should be consistent within a few meters. 

For the years 2017-2019, click here.  For 2022-2050, click here.
See the notes section at the bottom of this page.

 

10. For 2020-2023, astronomical phenomena are listed below with an emphasis on those events that will be visible from western South Dakota.  Note: lunar occultations are listed below only if visible from JMLC. 

The Islamic dates listed below are tabular and may vary from observation at any particular location.

Distances to the Moon, Sun, or a planet are for Earth-center to object-center.

 

 

2020

01/03 - 07:27:39 MST - Latest sunrise at HVO

01/05 - 00:48 MST - Earth closest to the Sun (0.9832 au)

01/05 - A partial Lunar Eclipse occurs that will not be visible here

01/14 - Year 2773 Ab Urbe Condita starts (Roman/Julian calendar)

01/25 (Saturday) - Chinese New Year (year of the Rat) - see notes

02/10 7h MST - Mercury at greatest elongation, 18° E.

02/18 - The Moon (2+ days past last quarter) occulted the planet Mars; as seen from the Journey Museum, the occultation was partial from 04:45:24.7 to 04:45:37.4 MST and then was total until 06:05:51.2 with the partial phase ending 06:06:05.5 MST.

03/08 - MDT in effect

03/19 21:50 MDT - Spring Equinox

03/23 - 20h MDT - Mercury at greatest elongation 28° W.

04/08 evening - Passover

04/12 - Easter Sunday

04/19 - Orthodox Easter

04/23 evening - Ramadan

05/23 evening - Eid ul-Fitr

06/04 - 7h MDT - Mercury at greatest elongation 24° E.

06/05 - a partial Lunar Eclipse occurs that will not be visible here, nor noticeable anywhere

06/14&15 - 05:08:59 MDT - Earliest sunrise at HVO

06/20 15:44 MDT - Summer Solstice, longest day of the year at HVO: 15h 29m 48s.

06/20-21 MDT - An Annular Solar Eclipse occurs that will not be visible here

06/25&26 - 20:40:37 MDT - Latest sunset at HVO

07/04 6h MDT - Earth farthest from the Sun (1.0167 au)

07/04 21:08 to 23:52 MDT - A partial penumbral lunar eclipse occurs, but will not be noticeable

07/14 2h MDT - Jupiter at opposition

07/15 4h MDT - Jupiter appears closest to Earth (4.1393 au)

07/20 16h MDT - Saturn at opposition

07/20 21h - Saturn appears closest (8.9947 au)

07/22 - 9h MDT - Mercury at greatest elongation 20° W.

08/12 18h MDT - Venus at greatest elongation, 45.8° W.

08/19 evening - Year 1442 Anno Hegira starts (Islamic)

09/18 evening - Year 5781 Anno Mundi starts (Jewish)

09/22 07:31 MDT - Fall Equinox

09/27 evening - Yom Kippur

10/01 - 10h MDT - Mercury at greatest elongation 26° E.

10/05 - Mars appears closest this evening

10/13 17:26 MDT - Mars at opposition

11/01 - MST returns

11/10 - 10h MST - Mercury at greatest elongation 19° W.

11/30 00:33 to 04:53 MST - A partial penumbral lunar eclipse occurs, but will not be noticeable to the eye

12/08&09 - 16:14:19 MST - Earliest sunset at HVO

12/10 evening - Hanukkah

12/12 - The Moon (2 days short of new) will occult the planet Venus late in the afternoon; at 14:24:23.5 the partial phase will begin, and the occultation will be total at 14:24:53, but the Moon will be below the horizon before the occultation ends.  EXTREME CAUTION IS ESSENTIAL when viewing an event near the Sun.  See the warning below.  Because you will be using little, if any, filtration, you must block the light from the Sun.  If using a telescope, you must take care to never allow the Sun to enter your (or your camera's) field of view.

12/14 - A total solar eclipse occurs, but will not be visible from anywhere near SD.

12/21 03:02 MST - Winter Solstice - Shortest day of the year at HVO: 8h 52m 56s

12/21 11:21 MST - Jupiter and Saturn are closest together at only 0.10 degrees apart. This is a fairly rare event (last time was in 2000, next time is in 2040).  At 6 PM MST on the 20th, as seen from Rapid City, the pair are only 0.13 degrees apart, but very low above the SW horizon.

 

Planets: Also see notes, below. Dates, in this section, mostly refer to the date on which the night starts, "midnight" means the middle of the night, not always 12:00 A.M.  For events at "midnight" the date refers to the start of the night in question. Dates associated with dawn or morning only are not referenced to the previous night. The data given here are valid for observers in western South Dakota.

 

Pairings: (revised 4/28/20) within 5 degrees: 01/20 - the Moon and Mars are 3.2 degrees apart at dawn; 02/18 the Moon and Mars 0.3° at dawn; 02/19 - the Moon and Jupiter 3.4° at dawn; 02/20 the Moon and Saturn 2.5° at dawn; 03/11 to 03/20 - Mars and Jupiter at dawn 4.6° down to 0.7 deg, 03/18 - the Moon and Jupiter 2.7° at dawn,  03/21 to 03/25 - Mars and Jupiter separated by between 0.9 to 2.9° on these mornings, 03/26 to 04/07 - Mars and Saturn at dawn 3.4° to start and then 0.9° on 03/31 then increasing to 4.4° on 04/0704/15 - Moon and Saturn 3.5° at dawn, 04/16 - the Moon and Mars 4.3° at dawn, 04/28 - Jupiter and Saturn 5.0° before dawn decreasing to 4.7° on 05/07 then increasing after 05/26 to 5.0 by 06/06;  05/12 - the Moon and Jupiter 3.1° at dawn; 05/15 - The Moon and Mars 4.9° at dawn;         05/21 - Mercury and Venus 1° at dusk and less than 5° from the 19th through the 23rd; 05/23 - The Moon, Mercury, and Venus no more than 4.3° at dusk; 06/08 - The Moon and Saturn 4.3° at midnight; 06/19 - the Moon and Venus 1.5° at dawn; 07/05 - The Moon and Saturn 3.5° late at night and on 07/06 3.2° at dawn; 07/17 - The Moon and Venus 3.7° at dawn, 08/01 - the Moon and Jupiter 3.2° at dusk separating as the night proceeds onward; Night of 08/08 and 09 - The Moon and Mars 1.6° from moonrise to dawn; 08/15 - The Moon and Venus 3.5° at dawn, 08/28 - the Moon and Jupiter 2.3° at dusk and 3.1° at midnight; 09/05 - the Moon and Mars 1.4° that night then 3.0 by dawn; 09/24 - The Moon and Jupiter 3.9° at dusk, 09/25 - the Moon and Saturn 3.9° at dusk, 10/02 - the Moon and Mars 1.8° at midnight; 10/22 - The Moon and Saturn 4.1° at dusk; 10/29 - The Moon and Mars (rising) 4.7° at dusk, 11/02 -  Jupiter and Saturn begin another dance at 5° apart on the 2nd of November closing to 0.1° at dusk on December 20 and 21 and ending at 2.3° at dusk on January 10, 2021;  11/13 - The Moon and Mercury 4.3° at dawn, 12/12 - the Moon and Venus 3.4° at dawn and 1.4° at noon; 12/20 - Jupiter and Saturn 0.1° at dusk, also close for many days before and after, as noted above.

Mercury appears in the evening in late-January growing higher, but dimmer, until February 10th when it is highest then starts to sink and disappears around February 21st.  It will reappear as a morning object in around March 6th, appear highest (but very low) around March 13th, and disappear before the end of March. It will reappear low and bright in the evening around May 13th, growing higher and dimmer until the end of May, disappear by mid-June. As a morning object, it will reappear around July 12th growing higher and brighter until July 26 or 27, and then sink until it is lost around August 8th. Its last apparition of the year will start around October 31st, then growing higher and brighter until November 9th after which, still bright at magnitude -0.7 it will sink out of sight at the end of November.

Venus will be a bright evening object as the year starts, but by late May sink out of sight. It will reemerge in mid-June, and remain as a bright morning object into 2021.

Mars, starts the year as a morning object, and gradually grows brighter but lower morning after morning.  By mid-March it will turn around and start appearing higher each morning while still growing brighter until after about August 17 it starts to appear a little lower each day at dawn while still growing brighter until mid-October when it becomes a full fledged evening object and starts to fade. It will remain an evening object into the next year.

Jupiter will appear as a morning object in mid-January and then grow in brightness to magnitude -2.8 in mid-July when it will be an all-night object. It will then become an evening object, and fade to -2.0 by the end of the year.

Saturn appears in the morning sky early in February, becoming an all-night object in mid-July, and then continues as an evening object into 2021.

Full Moon Nights: 01/10, 02/08, 03/09, 04/07, 05/06, 06/05, 07/04, 08/02, 09/01, 10/01, 10/30&31, 11/29, 12/29.  (See notes below.)

 

2021

01/02 - 07:28:17 MST - Latest sunrise at HVO

01/02 - 06:51 MST - Earth closest to the Sun (0.983257 au)

01/14 - Year 2774 Ab Urbe Condita starts (Roman/Julian calendar)

01/23 19h MST - Mercury at greatest elongation, 18.6° E.

02/12 (Friday) - Chinese New Year (year of the Ox) - see notes

03/06 - 4h MST - Mercury at greatest elongation 27.3° W.

03/14 - MDT in effect

03/20 03:37 MDT - Spring Equinox

03/27 evening - Passover

04/04 - Easter Sunday

04/12 evening - Ramadan

05/02 - Orthodox Easter

05/12 evening - Eid ul-Fitr

05/16 - 23:54 MDT - Mercury at greatest elongation 22° E.

05/26 - a Total Lunar Eclipse: first contact of the umbra at 3:45 MDT, totality starts at 5:09 and ends at 5:28 after the Moon has set and the Sun has risen.

06/10 - An Annular Solar Eclipse occurs that will not be visible here.  The eclipse starts as a partial at 2:12 MDT, as an annular at 3:50, is maximal (89.2%) at 4:43, reverts to partial at 5:34, and concludes at 7:11.  The best view is at 80.8° N, 66.5° W.

06/14&15 - 05:09:18 MDT - Earliest sunrise at HVO

06/20 21:32 MDT - Summer Solstice, longest day of the year at HVO: 15h 30m 9s.

06/25 Lunar occultation of the star Nunki (mag. 2.05) will begin, for observers at the Journey Museum, at 04:09:32.5 MDT but will end (05:01:14.7) after twilight has already become bright.

06/26 - 20:40:36 MDT - Latest sunset at HVO

07/04 - 14h MDT - Mercury at greatest elongation 21.6° W.

07/04 16h MDT - Earth farthest from the Sun (1.01673 au)

08/19 18h MDT - Jupiter at opposition

08/19 23h MDT - Jupiter appears closest to Earth (4.0132 au)

08/02 0h MDT - Saturn at opposition

08/09 evening - Year 1443 Anno Hegira starts (Islamic)

09/06 evening - Year 5782 Anno Mundi starts (Jewish)

09/13 - 21h MDT - Mercury at greatest elongation 26.8° E.

09/15 evening - Yom Kippur

09/22 13:21 MDT - Fall Equinox

10/24 23h MDT - Mercury at greatest elongation 18.4° W.

10/29 15h MDT - Venus at greatest elongation, 47.0° E.

11/07 - MST returns

11/19 - A partial lunar eclipse occurs. The umbral phase starts 00:18 MST, reaches a maximum of 99.4% at 02:03, and leaves the umbra at 03:47:30.

11/28 evening - Hanukkah

12/04 - A total solar eclipse occurs, but will not be visible from anywhere near here. The best view will be at 00:33:27 MST as seen from 76.8°S, 46.1°W.  Magnitude 1.019.

12/09 - 16:14:39 MST - Earliest sunset at HVO

12/20 - Shortest day of the year at HVO: 8h 52m 36s

12/21 08:59 MST - Winter Solstice;

Planets: Also see notes, below. Dates, in this section, mostly refer to the date on which the night starts, "midnight" means the middle of the night, not always 12:00 A.M.  For events at "midnight" the date refers to the start of the night in question. Dates associated with dawn or morning only are not referenced to the previous night. The data given here are valid for observers in western South Dakota.

 

Pairings within 5 degrees: (this section revised 04/29/2020) January 1 through 10 - Jupiter and Saturn closer than 2.3° in the evening, 1/10 - Mercury and Jupiter 1.7° at dusk; 1/11 - the Moon and Venus 3.5° at dawn, 1/11 - Mercury and Jupiter 1.4° at dusk,  1/12 - Mercury and Jupiter 2.2° at dusk,  1/13 - Mercury and Jupiter 3.3° at dusk,  2/18 - the Moon and Mars 3.9° at dusk, 2/19 thru 3/10 - Mercury and Saturn 4.7° or closer at dawn (closest 9.4° on 3/05),   4/06 - The Moon and Saturn 4.9° at dawn, 5/12 - the Moon and Venus 1.6° at dusk,  5/13 - the Moon and Mercury at dusk, 5/15 - The Moon and Mars 1.9° at dusk, 5/23-31 - Mercury and Venus at dusk (closest 0.4° on 5/28),  6/13 - the Moon and Mars 3.4° at dusk, 6/27 - the Moon and Saturn 4.8° at dusk, 7/04-21 - Venus and Mars at dusk (closest on 7/12 at 0.5 deg); 7/11 - the Moon and Venus 4.9° at dusk, 08/20 - the Moon and Saturn 4.9° at dusk, 08/21 - the Moon and Jupiter 4.6° at midnight, 9/09 - the Moon and Venus 3.5° at dusk, 9/16 - the Moon and Saturn less than 4.7° from dusk onward, night of 9/17 - the Moon and Jupiter 4.8 deg, 10/09 - the Moon and Venus 3° at dusk, 11/03 - the Moon and Mercury at dawn, 11/07 - the Moon and Venus 3.4° at dusk, 11/07-12 - Mercury and Mars at dawn (1.0° on 11/10); 12/06 - the Moon and Venus 3° at dusk, 12/27-29 - Mercury and Venus within 4.7° at dusk, 12/31 - the Moon and Mars 3.3° at dawn.

 

The planets (this section revised 04/29/2020):   

Mercury: Evenings Jan. 10 to Feb. 03, but best late January. Then mornings mid-Feb. to March 13, but poor.  Again an evening object from late April to late May, perhaps best in mid-May.  A poor showing in the mornings of late June to July 20+ - but growing brighter though never high (highest 6.9° July 10 and 11).  Then on the mornings of mid-October to early November, brightening to magnitude 0.6 and elevation 11.4° on 10/25 followed by some brightening but sinking lower and lower towards an end of the apparition near 11/12. Another evening appearance will start in late December.

Venus at the start of the year is a morning object low on the SE horizon, sinking lower day by day until exiting in mid-January.  It becomes an evening object around 05/08 but gains height above the horizon very slowly ( 15° at dusk in late November) and finishes the year as barely above the horizon.

Mars starts the year as an evening object at magnitude -0.2, but sets before sunrise and gradually becomes less bright until by early March it's 1.0 in magnitude and nearing setting by midnight.  Thereafter, Mars sets earlier and earlier, declines to magnitude 1.8, and fades from view in early August.  Mars reappears as a morning object in November.

Jupiter starts the year showing briefly in the evening sky before setting.  It is then lost in the Sun's glare until late February when it rises shortly before the Sun rises.  By June 11, it rises as a bright object (-2.5 mag.) rising in the middle of the night, and in mid-August is at its brightest (-2.9).  By mid-November, Jupiter sets before midnight, but continues as an evening object into 2022.

Saturn starts the year briefly visible in the West after sunset and is lost in the Sun's glare around January 10 until the last half of February when it becomes a morning object (mag. 0.7).  By late May it rises in the middle of the night, and late in July becomes an all-night object at magnitude 0.2.  By mid-October, Saturn sets in the middle of the night and is an early night object.

Full Moon Nights: 01/28, 02/26, 03/28, 04/26, 05/25, 06/24, 07/23, 08/21, 09/20, 10/19&20, 11/18, 12/18.  (See notes below.)

 

2022

01/02 - 07:28:17 MST - Latest sunrise at HVO

01/03 - 23:54 MST - Earth closest to the Sun (0.9833365 au)

01/07 04h MST - Mercury at greatest elongation, 19.2° E.

01/14 - Year 2775 Ab Urbe Condita starts (Roman/Julian calendar)

02/01 (Tuesday) - Chinese New Year (year of the Tiger) - see notes

02/16 - 15h MST - Mercury at greatest elongation 26.3° W.

03/13 - MDT in effect

03/20 - 3h MDT - Venus at greatest elongation 46.6° W.

03/20 09:33 MDT - Spring Equinox

04/02 evening - Ramadan

04/15 evening - Passover

04/17 - Easter Sunday

04/24 - Orthodox Easter

04/29 2h MDT - Mercury at greatest elongation 20.6° E.

04/30 - a partial solar eclipse starts at 12:45 MDT and ends at 16:38, but from HVO, and nearby, none of the sun's disk will be obscured. Best observer's position 62.87 S, 69.25 W, magnitude 0.639, 64% obscuration.

05/02 evening - Eid ul-Fitr

05/15 - a Total Lunar Eclipse occurs: first contact of the umbra at 20:28 MDT, totality starts at 21:29 and ends at 22:54 with the Moon outside the umbra at 23:55

06/15 - 05:09:17 MDT - Earliest sunrise at HVO

06/16 - 9h MDT - Mercury at greatest elongation 23.2° W.

06/21 03:14 MDT - Summer Solstice, longest day of the year at HVO: 15h 30m 9s.

06/26&27 - 20:40:38 MDT - Latest sunset at HVO

07/04 1h MDT - Earth farthest from the Sun (1.01672 au)

07/29 evening - Year 1444 Anno Hegira starts (Islamic)

08/14 11h MDT - Saturn at opposition

08/14 16h MDT - Saturn appears closest to Earth (8.8568 au)

08/27 10h MDT - Mercury at greatest elongation 27.3° E.

09/22 19:04 MDT - Fall Equinox

09/25 evening - Year 5783 Anno Mundi starts (Jewish)

09/25 20h MDT - Jupiter appears closest to Earth (3.9526 au)

09/26 14h MDT - Jupiter at opposition

10/04 evening - Yom Kippur

10/08 15h MDT - Mercury at greatest elongation 18.4° W.

10/11 The Moon will occult the planet Uranus (mag. 5.7); observers at the Journey Museum will see this start at 23:14:24.0 MDT with obscuration complete by 23:14:35.5 and reemergence starting at 00:05:08.6 and completed at 00:05:20.6.

10/25 - A partial solar eclipse occurs, but will not be visible from anywhere near here. The best view will be at 05:00 MDT as seen from 62.38° N, 79.77° E., magnitude 0.682, 82% obscured.

11/06 - MST returns

11/08 - A total Lunar Eclipse occurs: as seen at HVO, first contact with the umbra at 02:09 MST, totality from 03:16 to 04:42, and the Moon leaves the umbra at 05:49.

11/30 19h - Mars appears closest to Earth (0.544465 au)

12/07 6h - Mars at opposition

12/07 - Lunar occultation of Mars (mag. -1.9); for observers at the Journey Museum Mars will reach the Moon's edge at 19:51:28.9 MST, and be completely obscured at 19:52:07.3, reemergence will begin at 20:58:30.6 and be complete by 20:59:12.9.

12/09 - 16:14:39 MST - Earliest sunset at HVO

12/18 evening - Hanukkah

12/21 14:48 MST - Winter Solstice - Shortest day of the year at HVO: 8h 52m 36s

Planets: Also see notes, below. Dates, in this section, mostly refer to the date on which the night starts, "midnight" means the middle of the night, not always 12:00 A.M.  For events at "midnight" the date refers to the start of the night in question. Dates associated with dawn or morning only are not referenced to the previous night. The data given here are valid for observers in western South Dakota.

Pairings, within 5 degrees: (completely revised May 1, 2020) 01/03 - the Moon and Mercury 4.2° at dusk, 01/08 - Mercury and Saturn (5.0 deg) begin a series at dusk, they grow closest on January 12 and 13 (3.4 deg) and end 01/1601/29 - the Moon and Mars 3.2° at dawn, 02/02 - the Moon and Jupiter 4.5° at dusk, 02/27 - the Moon and Mars 4.9° at dawn, 03/01 - Venus and Mars are 5° apart in the pre-dawn sky with the separation down to  3.9 degrees on 03/13 to 03/18 then widening out for a few days, 03/25 - Venus and Saturn 3.9° at dawn converging to 2.1° on the 28th and 29th then diverging to 4.8° by 04/02,  03/31 - Venus, Mars, and Saturn within 3.2° of each other; 04/05 - Mars and Saturn 0.4° at dawn then 5.0° on the 12th, 04/25 - Venus and Jupiter 5.0° at dawn closing to 0.4° on the 30th and widening to 4.3° on 05/05, 05/21 - Mars and Jupiter 4.6° at dawn closing to 0.6° on the 29th then 4.7° on 06/06, 06/21 - the Moon and Jupiter 4.3° at dawn, 06/22 - the Moon and Mars 4.4° at dawn, 06/26 - the Moon and Venus 2.9° at dawn, 06/27 - the Moon and Mercury 3.8° at dawn, 07/18 - the Moon and Jupiter 3.8° at midnight, 07/20 - The Moon and Mars 4.0° at midnight closing to 2.3° at dawn, 07/26 - the Moon and Venus 3.7° at dawn, 08/11 - the Moon and Saturn under 5° most of the night, 08/14 - the Moon and Jupiter about 3° most of the night, 08/18 - the Moon and Mars 2.2 deg,  09/11 - the Moon and Jupiter 4.1° at dawn, 09/16 - the Moon and Mars 4.7° at midnight, 10/08 - the Moon and Jupiter 4.2° at dusk, 10/14 - the Moon and Mars 3.7° at midnight, 10/24 - the Moon and Mercury 0.7° at dawn - but barely above the Eastern horizon, 11/01 - the Moon and Saturn 4.9° at dusk, 11/04 - the Moon and Jupiter 3.3° at dusk and 4.8° at midnight, 11/10 - the Moon and Mars 3.7° at midnight then 2.2° at dawn, 12/01 - the Moon and Jupiter 3.5° at dusk then 2.8° at midnight, 12/07 - the Moon and Mars 1.8° at dusk, 1.3° at midnight then 4.2° at dawn, 12/22 - Mercury and Venus 5° at dusk closing to 1.4° on the 28th then 3.7° on January first, 12/24 - the Moon and Mercury 4.9° at dusk (with Venus also near),

 

Mercury: In early January is low, but bright, in the evening sky fading and sinking until it becomes lost in the glare by mid-January.  In February it becomes a poor target in the morning sky, then again disappears until mid-April when it becomes a bright, but fading object visible at dusk until May; around May first until mid-May it would be advisable to use binoculars or a telescope.  From mid-May Mercury is again lost until mid-June to early-July when it appears low in the sky at dawn.  From early August until late August it appears very low in the evening sky.  In October Mercury reappears in the sky at dawn growing brighter and higher (best October 6-12) then disappearing again late in the month.  Its last apparition is in the evening sky starting about December 9th, and peaking before Christmas.

Venus starts the year as an evening object low on the horizon, sinking lower day by day, and becomes a bright morning object in mid-January, it peaks in mid-February, then becomes lower sinking lowest in May, then climbing to another high point in July and then sinks lower in August until it is lost in mid-September before reappearing in the evening sky in mid-December.

Mars starts the year as a morning object at magnitude -1.5, and slowly becomes a little brighter until in April it starts gaining altitude at dawn  and steadily brightening.  On the night of December 8-9 Mars is brightest at magnitude -1.9 and is an all-night object.

Jupiter starts the year as an evening object until it sets soon after the Sun by mid-February. Jupiter becomes a morning object in early April.  It is best on the night of September 26 at magnitude -2.9 and is then an all-night object.  It finishes the year as a bright evening object.

Saturn starts the year as an evening object (magnitude 0.7) until late January.  It then reappears as a morning object early in March. By the night of August 14 it is an all-night object at magnitude 0.3, and thereafter becomes an evening object for the rest of the year.

Full Moon Nights: 01/17, 02/15-16, 03/17, 04/16, 05/15, 06/13, 07/13, 08/11, 09/09, 10/09, 11/07, 12/07.  (See notes below.)

 

 

 

2023

01/02&03 - 07:27:53 MST - Latest sunrise at JMLC

01/04 - 09:18 MST - Earth closest to the Sun (0.98330 au)

01/14 - Year 2776 Ab Urbe Condita starts (Roman/Julian calendar)

01/22 (Sunday) - Chinese New Year (year of the Rabbit) - see notes

01/29 - 23h MST - Mercury at greatest elongation, 25.0” W.

03/12 - MDT in effect

03/20 15:24 MDT - Spring Equinox

03/22 evening - Ramadan

04/05 evening - Passover

04/09 - Easter Sunday

04/11 - 16h MDT - Mercury at greatest elongation 19.5” E.

04/16 - Orthodox Easter

04/19 - a partial solar eclipse starts at 19:34 MDT, becomes an annular eclipse from 20:37:06, a total eclipse at 20:37:17, reaches the mid-point at 22:16:46, again becomes annular at 23:55:31, becomes partial at 23:56:40, and ends at 24:59:20, but from JMLC, and nearby, none of the sun's disk will be obscured. Best observer's position: 9.59 S, 125.78 E, magnitude 1.007.

04/21 evening - Eid ul-Fitr

05/05 - a Partial Penumbral Lunar Eclipse occurs from 09:14 to 13:31 MDT. The Moon will not be visible from the USA during this time.

05/28 23h MDT - Mercury at greatest elongation 24.9” W.

06/04 - 5h MDT - Venus at greatest elongation 45.4” E.

06/15 - 05:09:04 MDT - Earliest sunrise at JMLC

06/21 08:58 MDT - Summer Solstice, longest day of the year at JMLC: 15h 30m.

06/26&27 - 20:40:14 MDT - Latest sunset at JMLC

07/06 13h MDT - Earth farthest from the Sun (1.01668 au)

07/18 evening - Year 1445 Anno Hegira starts (Islamic)

08/09 19h MDT - Mercury at greatest elongation 27.4” E.

08/24 A lunar occultation of the star Antares (mag. 1.06) will begin, for observers at the Journey Museum, at 19:59:36.6 MDT and end at 21:11:40.2.

08/27 1h MDT - Saturn at opposition

08/27 5h MDT - Saturn appears closest to Earth (8.7630 au)

09/15 evening - Year 5784 Anno Mundi starts (Jewish)

09/22 - 7h MDT - Mercury at greatest elongation 17.9” W.

09/23 00:50 MDT - Fall Equinox

09/24 evening - Yom Kippur (Jewish)

10/14 - An annular solar eclipse occurs, but will be visible from anywhere near here as only a partial eclipse . The best view will be at 11:59 MDT as seen from 11.36” N, 83.11” W., magnitude 0.9764. From JMLC, the eclipse will be seen as a partial eclipse from 9:17:03 MDT until 12:02:31 with 64% of the Sun being blocked by the Moon at 10:36:32.

10/23 - 17h MDT - Venus at greatest elongation 46.4” W.

11/01 15h MDT - Jupiter appears closest to Earth (3.9824 au)

11/02 23h MDT - Jupiter at opposition

11/05 - MST returns

12/04 7h MDT - Mercury at greatest elongation 21.3” E.

12/07 evening Š Hanukkah (Jewish)

12/09 - 16:14:24 MST - Earliest sunset at JMLC

12/21 20:27 MST - Winter Solstice - Shortest day of the year at JMLC: 8h 52m 45s.

 

Planets: Also see notes, below. Dates, in this section, mostly refer to the date on which the night starts, "midnight" means the middle of the night, not always 12:00 A.M.  For events at "midnight" the date refers to the start of the night in question. Dates associated with dawn or morning only are not referenced to the previous night. The data given here are valid for observers in western South Dakota.

 

Pairings, within 5 degrees:  01/03 - the Moon and Mercury 4.2” at dusk, 01/08 - Mercury and Saturn (5.0 deg) begin a series at dusk, they grow closest on January 12 and 13 (3.4 deg) and end 01/1601/29 - the Moon and Mars 3.2” at dawn, 02/02 - the Moon and Jupiter 4.5” at dusk, 02/27 - the Moon and Mars 4.9” at dawn, 03/01 - Venus and Mars are 5” apart in the pre-dawn sky with the separation down to  3.9 degrees on 03/13 to 03/18 then widening out for a few days, 03/25 - Venus and Saturn 3.9” at dawn converging to 2.1” on the 28th and 29th then diverging to 4.8” by 04/02,  03/31 - Venus, Mars, and Saturn within 3.2” of each other; 04/05 - Mars and Saturn 0.4” at dawn then 5.0” on the 12th, 04/25 - Venus and Jupiter 5.0” at dawn closing to 0.4” on the 30th and widening to 4.3” on 05/05, 05/21 - Mars and Jupiter 4.6” at dawn closing to 0.6” on the 29th then 4.7” on 06/06, 06/21 - the Moon and Jupiter 4.3” at dawn, 06/22 - the Moon and Mars 4.4” at dawn, 06/26 - the Moon and Venus 2.9” at dawn, 06/27 - the Moon and Mercury 3.8” at dawn, 07/18 - the Moon and Jupiter 3.8” at midnight, 07/20 - The Moon and Mars 4.0” at midnight closing to 2.3” at dawn, 07/26 - the Moon and Venus 3.7” at dawn, 08/11 - the Moon and Saturn under 5” most of the night, 08/14 - the Moon and Jupiter about 3” most of the night, 08/18 - the Moon and Mars 2.2 deg,  09/11 - the Moon and Jupiter 4.1” at dawn, 09/16 - the Moon and Mars 4.7” at midnight, 10/08 - the Moon and Jupiter 4.2” at dusk, 10/14 - the Moon and Mars 3.7” at midnight, 10/24 - the Moon and Mercury 0.7” at dawn - but barely above the Eastern horizon, 11/01 - the Moon and Saturn 4.9” at dusk, 11/04 - the Moon and Jupiter 3.3” at dusk and 4.8” at midnight, 11/10 - the Moon and Mars 3.7” at midnight then 2.2” at dawn, 12/01 - the Moon and Jupiter 3.5” at dusk then 2.8” at midnight, 12/07 - the Moon and Mars 1.8” at dusk, 1.3” at midnight then 4.2” at dawn, 12/22 - Mercury and Venus 5” at dusk closing to 1.4” on the 28th then 3.7” on January first, 12/24 - the Moon and Mercury 4.9” at dusk (with Venus also near),

 

Mercury: Mercury can only be seen when it is sufficiently high in the sky before sunrise or after sunset. Its appearances typically last only a few days at a time. On 01/01 it is low in the sky and chasing the setting Sun in the evening sky.  By the 01/12 it becomes a dim object appearing in the morning sky just before sunrise. By 01/22 and 01/23 it is at its highest point for this apparition and has brightened to magnitude 0.0 after which it continues to brighten, but appears lower in the sky on successive mornings, sinking out of sight by around 02/13. Mercury reappears as a bright magnitude -1.4 evening object (and near Jupiter for three evenings) on 03/26. By 04/11 it will be as high as it will get for this apparition, but will then be dimmer at magnitude 0.0 as it continues to get lower and dimmer toward the end of the apparition around 04/24. Mercury will briefly make an appearance as a morning object low in the ENE sky from 06/02 to 06/11. It will reappear around 07/15 as an evening object around 07/15, rising higher (but losing some brightness) until around 07/28 and will then sink out of view around 08/10. As a morning object it will reappear around 09/12 as a dim magnitude 2.6 object in the morning getting higher and brighter until 09/22 (magnitude -9.5) and then while still gaining brightness sink back into the Sun's glare around 10/07. On about 11/26 it begins its last evening apparition of the year as a bright object that never gets very high, peaks around 12/08, and ends its show around 12/15. On 12/27 a morning apparition will start and extend into 2024.

Venus starts the year as an evening object low on the horizon, rising higher day by day until reaching its highest point around 04/30, and sinking back into the SunÕs glare around 07/22. It becomes a bright morning object around 08/23, peaking around 10/21, then continues its show into 2024 while losing altitude.

Mars starts the year as an evening object at magnitude -1.2 and sets before sunrise. It slowly loses a little brightness each day until by early May it sets before the middle of the night and has dimmed to magnitude 1.4. It then continues to sink lower against the western horizon night after night until early September when it has dimmed to magnitude 1.7 or so and is seen only briefly after sunset and is done for the year.

Jupiter starts the year as an evening object until it sets soon after the Sun by late March. Jupiter becomes a morning object in mid-May.  It is best on the night of 11/02 at magnitude -2.9 and is then an all-night object.  It finishes the year as a bright evening object.

Saturn starts the year as an evening object (magnitude 0.8) until early February.  It then reappears as a morning object around 03/18. By the night of 08/27 it is an all-night object at magnitude 0.4, and thereafter becomes an evening object for the rest of the year.

Full Moon Nights: 01/05, 02/04-05, 03/06, 04/05, 05/04, 06/03, 07/02, 07/31, 08/30, 09/28, 10/27-28, 11/26, 12/26.  (See notes below.)

 

 

 

NOTES:

 

Observing The Sun -- WARNING  --  WARNING  --  WARNING !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Extreme caution must be used by anyone trying to view the sun.  You must block most of the visible light, and virtually all of the UV and infra-red coming from the sun.  Viewing the sun is inherently dangerous.  Dark photographic materials are NOT designed to reduce sunlight to a safe level, especially UV and IR!  If a filter slips off your telescope, or your binoculars, your eye can be permanently damaged before you can react. Sunlight concentrated by a lens or telescope can overheat a filter causing it to melt or crack, and then you or your equipment will be at severe risk; therefore, sunlight must be filtered BEFORE entering any optical instrument or camera. Prolonged viewing of the sun requires great care and knowledge.  Viewing the sun safely requires previous study and setting up the equipment well in advance. Last minute preparation is likely to lead to disaster!  Please be sure you know what you are doing, and that you have the proper equipment with secure attachments if you wish to view or record solar phenomena. Do not hesitate to seek help from an experienced observer.

 

About the precision and accuracy of the listed times for specific events: Where times are listed to a precision of one second, or better, it should be understood that the calculation process has yielded a result to that precision, but several caveats apply:  (1) even though the calculation in question might depend only on TT, the quantities DUTC = TT-UTC, and DUT1 = TT-UT1, for future dates can only be estimated.  For events that directly depend on DUT1, even TT becomes an estimate. (2) For most events, observational precision is difficult and expensive - if not impossible.  The chief exception to this is a lunar occultation of a bright star; but even in this case there are difficulties requiring great care in recording the event, determining accurately the observer's position, and establishing the time with high accuracy (in general, battery operated clocks are rated as good only to one-second accuracy at best) and clocks that use GPS, or frequent NTP updates, are required for errors no more than one tenth of a second.

 

About the dates of religious observances: These dates are conceptually tied to astronomical phenomena, and cannot be simply predicted.  In the case of Christian and Jewish festivals the dates are determined by rigorous, but complicated, mathematics.  In the case of Islamic observances, many adherents believe that the calendar can only be determined from direct observation in each community; the dates shown here are determined algorithmically and should differ from direct observation by no more than a day or two.  The numbering of years in the Roman system (A.U.C.), although relatively simple, is also shown because of its historical importance.  For a table showing the dates of Ash Wednesday, Easter, and Eastern Orthodox Easter for 1900-2100 click here. For the dates of the Chinese New Year, see the note below.

 

About visibility of the planets: The narrative provided above on this page is specific to the latitude of the Hidden Valley Observatory, and should be reasonably accurate for latitudes between 42 and 46 degrees north, but increasingly inaccurate for observers farther north or south. The dates given are for the date on which a given night begins.  The times given are for the end of evening twilight (E), the middle of the night (m), and the start of civil twilight in the morning (M); they are specific to the vicinity of the observatory.  The elevation of a planet above the horizon is given in degrees for those times - if the planet's elevation is at least 3 degrees. Click here for more detailed information.

 

About Full Moon Nights: On the night of a full moon, and for a few nights before and after, the brightness of the moon may hinder observation of objects other than the moon.  It occasionally happens that two nights in succession "enjoy" being about equal in moon brightness. Click here for more detailed information on visibility of the moon (corrected 10/14/2016).

 

About "Super Moons":  The Moon is "full" when it is 180 degrees away from the Sun (in right ascension) and thus appears fully illuminated.  However, its distance (from the Earth's center to the Moon's center) varies as the Moon moves in its orbit, and ranges from less than 357,000 km (at perigee) to more than 406,000 km (at apogee).  Naturally, it appears bigger when it is closer, and the popular press has taken to calling a full moon near a perigee that is particularly close to the Earth a "Super Moon".  In this discussion, particularly close will be defined as closer than 357,000 km.  The full moon of September 27, 2015 in the evening at a distance of 356,878 km thus qualifies as a Super Moon, and the next one was on the morning of November 14, 2016 at 356,520 km - this will be the closest Super Moon until 2034, but there will be less notable Super Moons in 2018, 2019, 2025, 2026, 2028, 2029, 2032, and 2033 also.

 

About Lunar Occultations:  The moon can, for a time, block an observer's view of a star or a planet.  Only occultations of bright stars and bright planets are listed on this page; and only if the event is visible for an observer at the Hidden Valley Observatory, or the Journey Museum and Learning Center.  The timing of an occultation is highly dependent on the observer's location, and is very sensitive to any inaccuracies in the computation of the coordinates of the moon and the star or planet involved.  Therefore, accurate times for actual observations are of great interest.  An extensive listing of lunar occultations is available here.

 

About Chinese New Year (Lunar New Year): This is determined by the date and time in China (UTC+8 hours) and is assigned to the date when a new moon first occurs on or after January 21.  The last possible date for this is February 20.  Once this date is calculated according to Chinese time, the same date is used also in the United States and the rest of the world (although, as an example, 6 PM in the evening on January 21 in San Francisco corresponds to 10 AM on the 22nd in China; moreover, it seems that celebrations outside of China may indeed start according to the time in China rather than local date-time).  No correction for the equation of time is made when computing the date of the new year, i.e. the calculations are referenced to UTC+8 hours, not local solar time on a selected meridian.  The actual time of day for the new moon is irrelevant unless it is so close to midnight as to introduce an ambiguity as to the date.  For a listing of the dates from 2015 through 2050, click here.

 

About daily polynomials for lunar coordinates: The Astronomical Almanac lists the apparent right ascension, apparent declination, and true distance (light time not factored in) of the moon at zero hours Terrestrial Time for each day of the year. 

The online web site at http://asa.hmnao.com/SecD/LunarPoly.html gives daily polynomials (for the years 2000-2018) for apparent right ascension, apparent declination, and horizontal parallax for any desired time during the day listed.  However, there are a few points to consider: (1) the polynomials for years after 2018 are not posted as of May, 2020 - and there is no indication on that website that they ever will be provided for years after 2018, nor do I know of an alternative website other than this one.  (2) The coefficients there for horizontal parallax do not have the required number of significant figures to match the distance information listed in the Astronomical Almanac, but the required precision is provided here.

 

Please report corrections and suggestions to g e o r g e 0 7 @ r a p . m i d c o . n e t   (using no spaces in the address).