Archive
02/14/2022 – Ephemeris – A celestial Valentine’s Day encounter
This is Bob Moler with Ephemeris for St Valentine’s Day, Monday, February 14th. Today the Sun will be up for 10 hours and 25 minutes, setting at 6:10, and it will rise tomorrow at 7:43. The Moon, 2 days before full, will set at 7:40 tomorrow morning.
Twenty-two years ago to the day, the NEAR-Shoemaker* spacecraft entered into orbit of the near Earth asteroid 433 Eros. It wasn’t originally planned to enter orbit of the asteroid named after the Greek god of love on Valentine’s Day, 2000. It arose after an aborted course correction a year earlier. After solving the problem, a new course was plotted and NEAR-Shoemaker was gently inserted into orbit of this 21 mile long asteroid shaped like a bent bread stick with a bite taken out of the center of it. The spacecraft spent almost a year orbiting Eros at various altitudes. The spacecraft ended its mission gently crashing into the middle of the asteroid, where it stayed alive for two weeks before succumbing to the cold.
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.
*The name Shoemaker was added to the NEAR spacecraft name after it was launched. NEAR stands for Near Earth Asteroid Rendezvous. It was named for Eugene Shoemaker, a geologist who proved that the Barringer Crater in Arizona was an impact crater rather than a volcanic crater, thus proving, before the Apollo 11 landing on the Moon, that the Moon’s craters were mostly impact craters produced by small asteroids like Eros. Shoemaker and his wife Carolyn, the astronomer in the family, along with David Levy discovered the Comet Shoemaker-Levy 9. The comet had broken into more than 22 pieces and crashed into Jupiter over a week in July 1994, making blemishes in the Jovian clouds that lasted many months.
Addendum
“These color images of Eros were taken by the NEAR probe on February 12, 2000, at a distance of 1,800 kilometers, during the final approach imaging sequence before insertion into orbit. The images show the approximate color of Eros as it would be seen with the naked eye.” Click on the image to enlarge it. Credit
NASA/JPL/JHUAPL. Caption from: https://eros2019.imcce.fr/eros.html via Google Translate.
By the way, the Roman equivalent to Eros was the god Cupid, whose love dart is the constellation Sagitta, which resides within the Summer Triangle of bright stars, to be seen in the evening sky four months from now.
I’ll end with a Valentine heart. The red color is real, it’s due to hydrogen.
IC 1805 (Heart Nebula) Credit: s58y [CC BY 2.0 (https://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons.
02/11/2022 – Ephemeris – The Sun Rises on the Moon’s Bay of Rainbows
This is Ephemeris for Friday, February 11th. Today the Sun will be up for 10 hours and 16 minutes, setting at 6:05, and it will rise tomorrow at 7:47. The Moon, 3 days past first quarter, will set at 5:34 tomorrow morning.
On the moon tonight, the gibbous phase and the terminator on the left side of the moon is revealing a large semicircular mountain range called the Jura Mountains that encloses a flat lava plain that looks like a bay in the margin of the Sea of Showers or Mare Imbrium. It is easily visible in binoculars this evening, when the sunrise line is crossing the bay. The Jura Mountains will appear as a hook out of the upper left edge of the moon. That’s about the coolest sight that’s visible on the moon that can be seen with binoculars. It’s especially striking if seen in a small telescope.
Also, related to the Moon: The Artemis-1 uncrewed mission to orbit the Moon has been pushed off at least one month or more, to this April or even May.
Addendum
Sunrise at Sinus Iridium, full Moon disc with annotations. Click on the image to enlarge it. Moon image created using Stellarium.
Sinus Iridium at sunrise. Photo by “Seb2003” on http://forums.futura-sciences.com/materiel-astronomique-photos-damateurs/5809-images-de-lune.html.
02/10/2022 – Ephemeris – The waxing gibbous Moon is revealing more seas and craters
This is Ephemeris for Thursday, February 10th. Today the Sun will be up for 10 hours and 14 minutes, setting at 6:04, and it will rise tomorrow at 7:48. The Moon, 2 days past first quarter, will set at 4:38 tomorrow morning.
The Moon tonight is a waxing gibbous phase. More gray lunar seas are appearing near the terminator, the sunrise line. From north to south these seas, most only partially in sunlight, are: At the far north, the Cold Sea, Sea of Showers, The sea where the famous crater Copernicus is, the Sea of Islands. The southernmost sea at the terminator is the Sea of Clouds. Some large and prominent craters can be seen with binoculars or a small telescope can be seen in the south, the striking and relatively fresh Tycho, with its Moon girdling ejecta rays, though the rays are best seen at full moon. And the huge crater Clavius, with an arc of 5 smaller craters, one on its wall and the others on its floor, in ever diminishing sizes.
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
2 days past first quarter Moon as it would be seen in a small telescope or even binoculars, annotated. For this evening, February 10, 2022. Click on the image to enlarge it. Created using Virtual Moon Atlas. Annotations in white are from the app, mine are in green. Translations of the sea names are below.
Translations
Mare Crisium – Sea of Crises
Mare Fecunditatis – Sea of Fertility
Mare Frigoris – Sea of Cold
Mare Imbrium – Sea of Showers
Mare Insularum – Sea of Islands
Mare Nectaris – Sea of Nectar
Mare Nubium – Sea of Clouds
Mare Serenitatis – Sea of Serenity
Mare Tranquilitatis – Sea of Tranquility
A closer look
A montage of Clavius as photographed by one of the Lunar Orbiter spacecraft in the 1960s From Digital Lunar Orbital Photographic Atlas. Credit Jeff Gillis, Lunar and Planetary Institute.
02/09/2022 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Ephemeris for Wednesday, February 9th. Today the Sun will be up for 10 hours and 11 minutes, setting at 6:02, and it will rise tomorrow at 7:50. The Moon, 1 day past first quarter, will set at 3:37 tomorrow morning.
Let’s search for the naked-eye planets for this week. There is just one planet left in the evening sky now, and it’s going to leave us soon. Jupiter will be visible in the west-southwest around 6:30 pm. It will set at 7:35 pm. Saturn is too close to the Sun to be seen, It crossed behind the Sun last Friday, and has entered the morning sky, where we will lose it for a month or so. Speaking of the morning sky, Venus, our brilliant morning star, Mars and maybe even Mercury can be spotted low in the southeast by 7 o’clock. Mars will be below, right of Venus, while Mercury will be near the horizon left of Venus. Mercury is brighter than Mars, but lower in more intense twilight. Venus will rise at 5:23, with Mars following at 5:53, and Mercury rising last at 6:32.
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 in evening twilight tonight at 6:30 pm or about a half hour after sunset, February 9, 2022. Created using Stellarium.
The waxing gibbous Moon as it might appear tonight in binoculars or small telescope. Created using Stellarium.
Venus, Mars, and Mercury at 7 am, or about 50 minutes before sunrise in the morning twilight. Created using Stellarium.
Telescopic views of the Jupiter and its moons; and Venus (north up) as they would be seen in a small telescope, with the same magnification, overnight, February 9/10, 2022. As far as Jupiter is concerned, I’m not sure its moons will be visible in the twilight or close to the horizon. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Jupiter, 33.34″ at 6:45 pm. Mars is not shown, its apparent diameter is 4.44″. Venus has an apparent diameter of 42.07″ and is 23.8% illuminated at 7 am. Mercury, is also not shown, it has an apparent diameter of 7.73″ and it’s 47.3% illuminated. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on February 9, 2022. The night ends on the left with sunrise on the 10th. Click on the image to enlarge it. Created using my LookingUp program.
02/08/2022 – Ephemeris – The first quarter Moon tonight
This is Ephemeris for Tuesday, February 8th. Today the Sun will be up for 10 hours and 8 minutes, setting at 6:01, and it will rise tomorrow at 7:51. The Moon, at first quarter today, will set at 2:34 tomorrow morning.
The Moon tonight, will be about 12 hours past being exactly first quarter, so it will be showing to be just a bit gibbous, that is a bit more than 50% illuminated by the Sun from our vantage point. In binoculars, the gray lunar seas, which are actually frozen lava filled plains, dominate the upper right quarter of the Moon. At the bottom, or south end of the Moon are the lighter more cratered region of the Moon called the Lunar Highlands. It is near the terminator, the line between day and night on the Moon, where shadows are longest, where craters can be seen by the shadows of the rims. Farther away from the terminator, the Sun is higher in the Moon’s sky, so the shadows get shorter or disappear all together.
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
The is what the Moon might look like tonight, hours after first quarter. Just a bit of Mare Imbrium (Sea of Showers) is visible. Mare Serenitatis is the Sea of Serenity, Mare Tranquilitatis is the Sea of Tranquility. The green annotation is mine. BTW, Mare is pronounced Mar-e. It’s Latin, meaning sea. Created using Virtual Moon Atlas, a free app that can be downloaded from a link on the right, or listed under Free Astronomical Software.
02/07/2022 – Ephemeris – The Moon tonight
This is Ephemeris for Monday, February 7th. Today the Sun will be up for 10 hours and 5 minutes, setting at 6:00, and it will rise tomorrow at 7:53. The Moon, 1 day before first quarter, will set at 1:29 tomorrow morning.
Tonight, let’s take a look at the nearly first quarter Moon. The small, nearly circular gray spot is the sea of Crises. A diagonal chain of larger seas run from the terminator, the sunrise line, to below the Sea of Crises. They are, from the terminator, the seas of Serenity, Tranquility and Fertility. NASA is hoping to launch its uncrewed mission to the Moon, Artemis-1, next month with a large block of launch dates. The launch window begins on March 12th and ends on the 27th, with two blackout dates. Two lengths of missions are possible, a long 38 to 42 day mission is possible in the first part of the launch window, and a shorter 26 to 28 day mission is possible in the latter part of the window.
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
The Moon as it might appear tonight in binoculars or a small telescope at 7 pm tonight, February 7, 2022. I labeled the lunar seas with their English names, translated from the Latin. Also labeled is the Sea of Nectar, which wasn’t mentioned in the program. Moon image created using Stellarium.
02/02/2022 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Ground Hog Day, Wednesday, February 2nd. Today the Sun will be up for 9 hours and 52 minutes, setting at 5:52, and it will rise tomorrow at 7:59. The Moon, 1 day past new, will set at 7:42 this evening.
Let’s search for the naked-eye planets for this week. There is just one planet left in the evening sky now. Jupiter will be visible in the west-southwest by 6:30 pm. The thin crescent Moon will appear below and left of it tonight. It’s kind of hard to tell which will be brighter. Jupiter will set at 7:54 pm. Saturn is too close to the Sun to be seen, and will cross behind the Sun on Friday, and will then enter the morning sky, where we will lose it for a month or so. Speaking of the morning sky, Venus, our brilliant morning star, will be in the southeast by 7 o’clock with the much dimmer Mars to the right and below it. Venus will rise at 5:40, with Mars following at 5:59. Antares is Mars’ rival in color and brightness, the red giant star Antares will be in the south-southeast at 7. Mars is speeding away from 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
Jupiter and the Moon in twilight at 6:30 pm tonight, February 2, 2022. Created using Stellarium.
This is what tonight’s one-day old Moon might look like in a pair of binoculars at 6:30 pm, February 2, 2022. The image shows earth shine, the reflected light of a nearly full Earth on The Moon’s night side. Created using Stellarium.
Venus and Mars in the morning at 7:00 tomorrow morning, February 2, 2022. Created using Stellarium.
Telescopic views of the bright planets and their brighter moons (north up) as they would be seen in a small telescope, with the same magnification, overnight, February 2/3, 2022. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Jupiter, 33.56″ at 7 pm. Mars is not shown, its apparent diameter is 4.35″. Venus has an apparent diameter of 47.25″ and is 17.5% illuminated at 7 am. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on February 2, 2022. The night ends on the left with sunrise on the 3rd. Click on the image to enlarge it. Created using my LookingUp program.
02/01/2022 – Ephemeris – Let’s look ahead at our short month of February
This is Bob Moler with Ephemeris for Tuesday, February 1st. Today the Sun will be up for 9 hours and 49 minutes, setting at 5:51, and it will rise tomorrow at 8:00. The Moon is new today, and won’t be visible.
Let’s look ahead at our short month of February. We’re in the depths of winter, but the Sun is continuing its return to northern climes. This is reflected in the increase in daylight hours, from 9 hours 49 minutes today to 11 hours 7 minutes on the 28th. These times are for the Interlochen/Traverse City area. The duration of daylight is slightly shorter in the northern part of our listening area and slightly longer to the south. As the month goes on, the weather should generally warm and clear up. We will be slowly losing Jupiter from the evening sky this month. Venus is moving away from the Sun and will pass Mars in the morning sky on the 12th. Neither Mercury nor Saturn will be visible this month because they will be lost in the Sun’s glare.
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
February Evening Star Chart
Star Chart for February 2022, (9 p.m. EST February 15, 2022). Created using my LookingUp program. Click on image to enlarge.
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. 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 1 hour 45 minutes earlier than the current time.
Note the chart times of 9 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. The planet positions are updated each Wednesday on this blog. For planet positions on dates other than the 15th, check the Wednesday planet posts on this blog.
February Morning Star Chart
Star Chart for February mornings, 2022 (6 a.m. EST February 15, 2022). Created using my LookingUp program. Click on image to enlarge.
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.
- Follow the arc of the handle of the Big Dipper to the star Arcturus, and
- Extend like a spike to Spica,
- The Summer Triangle is in red.
Twilight Limits, Nautical and Astronomical
| EST | |||||||
| Morning | Twilight | Evening | Twilight | Dark | Night | Moon | |
| Date | Astro. | Nautical | Nautical | Astro. | Start | End | Illum. |
| 2022-02-01 | 6h22m | 6h56m | 18h56m | 19h30m | 19h30m | 6h22m | 0.01 |
| 2022-02-02 | 6h21m | 6h55m | 18h57m | 19h31m | 19h43m | 6h21m | 0.05 |
| 2022-02-03 | 6h20m | 6h54m | 18h59m | 19h33m | 20h57m | 6h20m | 0.11 |
| 2022-02-04 | 6h19m | 6h53m | 19h00m | 19h34m | 22h08m | 6h19m | 0.19 |
| 2022-02-05 | 6h18m | 6h52m | 19h01m | 19h35m | 23h17m | 6h18m | 0.28 |
| 2022-02-06 | 6h17m | 6h51m | 19h02m | 19h36m | – | 6h17m | 0.37 |
| 2022-02-07 | 6h16m | 6h50m | 19h04m | 19h38m | 0h23m | 6h16m | 0.47 |
| 2022-02-08 | 6h15m | 6h49m | 19h05m | 19h39m | 1h29m | 6h15m | 0.56 |
| 2022-02-09 | 6h13m | 6h47m | 19h06m | 19h40m | 2h34m | 6h13m | 0.65 |
| 2022-02-10 | 6h12m | 6h46m | 19h08m | 19h41m | 3h38m | 6h12m | 0.74 |
| 2022-02-11 | 6h11m | 6h45m | 19h09m | 19h43m | 4h39m | 6h11m | 0.82 |
| 2022-02-12 | 6h10m | 6h43m | 19h10m | 19h44m | 5h35m | 6h10m | 0.89 |
| 2022-02-13 | 6h08m | 6h42m | 19h11m | 19h45m | – | – | 0.94 |
| 2022-02-14 | 6h07m | 6h41m | 19h13m | 19h47m | – | – | 0.98 |
| 2022-02-15 | 6h06m | 6h39m | 19h14m | 19h48m | – | – | 1 |
| 2022-02-16 | 6h04m | 6h38m | 19h15m | 19h49m | – | – | 1 |
| 2022-02-17 | 6h03m | 6h37m | 19h17m | 19h50m | – | – | 0.98 |
| 2022-02-18 | 6h01m | 6h35m | 19h18m | 19h52m | 19h52m | 20h32m | 0.93 |
| 2022-02-19 | 6h00m | 6h34m | 19h19m | 19h53m | 19h53m | 21h43m | 0.87 |
| 2022-02-20 | 5h58m | 6h32m | 19h20m | 19h54m | 19h54m | 22h55m | 0.79 |
| 2022-02-21 | 5h57m | 6h31m | 19h22m | 19h55m | 19h55m | – | 0.69 |
| 2022-02-22 | 5h55m | 6h29m | 19h23m | 19h57m | 19h57m | 0h10m | 0.58 |
| 2022-02-23 | 5h54m | 6h28m | 19h24m | 19h58m | 19h58m | 1h26m | 0.47 |
| 2022-02-24 | 5h52m | 6h26m | 19h26m | 19h59m | 19h59m | 2h43m | 0.36 |
| 2022-02-25 | 5h51m | 6h24m | 19h27m | 20h01m | 20h01m | 3h58m | 0.25 |
| 2022-02-26 | 5h49m | 6h23m | 19h28m | 20h02m | 20h02m | 5h04m | 0.16 |
| 2022-02-27 | 5h47m | 6h21m | 19h30m | 20h03m | 20h03m | 5h47m | 0.08 |
| 2022-02-28 | 5h46m | 6h19m | 19h31m | 20h05m | 20h05m | 5h46m | 0.03 |
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 Event
Feb 1 Tu Venus: 32° W
1 Tu 12:46 am New Moon
2 We 4:08 pm Moon-Jupiter: 4.4° N
4 Fr 1:34 pm Saturn Solar Conjunction
8 Tu 8:50 am First Quarter
9 We 1:12 am Moon Ascending Node
10 Th 9:39 pm Moon Apogee: 404,900 km
12 Sa 11:45 am Moon North Dec.: 26.4° N
12 Sa 8:00 pm Venus-Mars: 6.6° N
13 Su 5:52 pm Moon-Pollux: 2.8° N
13 Su Venus greatest brilliancy
14 Mo 6:42 pm Moon-Beehive: 3.5° S
16 We 11:57 am Full Snow Moon
16 We 3:59 pm Mercury Elongation: 26.3° West
23 We 1:54 am Moon Descending Node
23 We 5:32 pm Last Quarter
26 Sa 1:37 am Moon South Dec.: 26.6° S
26 Sa 5:18 pm Moon Perigee: 367,800 km
27 Su 4:00 am Moon-Mars: 3.5° N
28 Mo 3:07 pm Moon-Mercury: 3.8° N
28 Mo 6:47 pm Moon-Saturn: 4.3° N
Mar 1 Tu Venus: 45° W
All event times are given for UTC-5:00: Eastern Standard or Daylight 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 February, 2022 Local time zone: EST +-----------------------------------------------------------------------+ | DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM | | | RISE SET HOURS | END START |PHASE SET** TIME FRACTN| +=======================================================================+ |Tue 1| 08:01a 05:51p 09:49 | 06:57p 06:55a |New Set 06:23p 1%| |Wed 2| 08:00a 05:52p 09:52 | 06:58p 06:54a | Set 07:42p 4%| |Thu 3| 07:59a 05:54p 09:54 | 07:00p 06:53a | Set 08:57p 10%| |Fri 4| 07:58a 05:55p 09:57 | 07:01p 06:52a | Set 10:08p 17%| |Sat 5| 07:56a 05:57p 10:00 | 07:02p 06:51a | Set 11:16p 26%| +------+-----------------------+----------------+-----------------------+ |Sun 6| 07:55a 05:58p 10:03 | 07:04p 06:50a | Set 12:23a 35%| |Mon 7| 07:54a 06:00p 10:05 | 07:05p 06:49a | Set 01:29a 44%| |Tue 8| 07:53a 06:01p 10:08 | 07:06p 06:48a |F Qtr Set 02:34a 54%| |Wed 9| 07:51a 06:02p 10:11 | 07:07p 06:46a | Set 03:37a 63%| |Thu 10| 07:50a 06:04p 10:14 | 07:09p 06:45a | Set 04:38a 72%| |Fri 11| 07:48a 06:05p 10:16 | 07:10p 06:44a | Set 05:34a 80%| |Sat 12| 07:47a 06:07p 10:19 | 07:11p 06:42a | Set 06:24a 87%| +------+-----------------------+----------------+-----------------------+ |Sun 13| 07:46a 06:08p 10:22 | 07:13p 06:41a | Set 07:05a 93%| |Mon 14| 07:44a 06:10p 10:25 | 07:14p 06:40a | Set 07:40a 97%| |Tue 15| 07:43a 06:11p 10:28 | 07:15p 06:38a | Set 08:09a 99%| |Wed 16| 07:41a 06:12p 10:31 | 07:16p 06:37a |Full Rise 06:11p 100%| |Thu 17| 07:39a 06:14p 10:34 | 07:18p 06:36a | Rise 07:21p 98%| |Fri 18| 07:38a 06:15p 10:37 | 07:19p 06:34a | Rise 08:32p 94%| |Sat 19| 07:36a 06:17p 10:40 | 07:20p 06:33a | Rise 09:42p 88%| +------+-----------------------+----------------+-----------------------+ |Sun 20| 07:35a 06:18p 10:43 | 07:22p 06:31a | Rise 10:55p 81%| |Mon 21| 07:33a 06:19p 10:46 | 07:23p 06:30a | Rise 12:09a 71%| |Tue 22| 07:32a 06:21p 10:49 | 07:24p 06:28a | Rise 01:26a 61%| |Wed 23| 07:30a 06:22p 10:52 | 07:26p 06:26a |L Qtr Rise 02:43a 49%| |Thu 24| 07:28a 06:23p 10:55 | 07:27p 06:25a | Rise 03:57a 38%| |Fri 25| 07:27a 06:25p 10:58 | 07:28p 06:23a | Rise 05:04a 27%| |Sat 26| 07:25a 06:26p 11:01 | 07:29p 06:22a | Rise 05:59a 18%| +------+-----------------------+----------------+-----------------------+ |Sun 27| 07:23a 06:27p 11:04 | 07:31p 06:20a | Rise 06:43a 10%| |Mon 28| 07:21a 06:29p 11:07 | 07:32p 06:18a | Rise 07:17a 4%| +-----------------------------------------------------------------------+ * Nautical Twilight ** Moonrise or moonset, whichever occurs between sunrise and sunset
Created using my LookingUp for DOS output as HTML.
Bob Moler's Ephemeris Blog 