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08/04/2022 – Ephemeris – The Late Heavy Bombardment
This is Bob Moler with Ephemeris for Thursday, August 4th. Today the Sun will be up for 14 hours and 32 minutes, setting at 9:04, and it will rise tomorrow at 6:33. The Moon, 1 day before first quarter, will set at 12:19 tomorrow morning.
The face of the Moon is nearly half uncovered from our point of view, with first quarter occurring at 7:06 tomorrow morning. It shows the string of lunar seas, those gray areas on the moon which lead to the terminator, the Moon’s sunrise line. There are even more and larger seas on the east half of the Moon, as we see it. Most were created about 3.9 billion years ago by asteroid strikes. The same thing happened to the Earth, but plate tectonics destroyed the evidence. Not so on the Moon. The result, many planetary scientists think, was the Late Heavy Bombardment, caused by the changing orbits of mainly Saturn, Uranus and Neptune disrupting the smaller asteroids, and sending them careening through the solar system.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.
Addendum
First quarter Moon with prominent seas labeled. Created using Stellarium, GIMP and LibreOffice.
Nice model infographic: Evolution of the solar system. Step 6, with the exchange of Neptune’s and Uranus’ orbits, cause the Late Heavy Bombardment. The Nice model isn’t that nice. It’s named for Nice, France, the city where the model was first developed. The original on the web page was smaller. I enlarged it and sharpened it a bit, so it’s more readable. Credit: Nora Eisner.
The above infographic is from the blog post at https://blog.planethunters.org/2019/04/29/formation-of-our-solar-system/ by Nora Eisner.
08/03/2022 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Ephemeris for Wednesday, August 3rd. Today the Sun will be up for 14 hours and 34 minutes, setting at 9:05, and it will rise tomorrow at 6:32. The Moon, 2 days before first quarter, will set at 11:56 this evening.
Let’s search for the naked-eye planets for this week. All but one of the naked-eye planets are in the morning sky, That one is Mercury, too close to the Sun to be seen in the evening. At 5:30 tomorrow morning, the planets will be spread out from brilliant Venus low in the east-northeast to Saturn in the southwest. Mars will be a lot higher than Venus in the southeast. Jupiter is farther to the right in the south. Mars is dimmer than Jupiter, but is slowly getting brighter as the Earth creeps up on it. Saturn ends the line of planets much lower than Jupiter in the southwest. Tonight, Saturn will rise about 9:33 pm in the east-southeast, though it won’t be an official evening planet until it rises before sunset, which is 11 days away.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.
Addendum
The annotated Moon for 10:30 this evening, August 3, 2022. Labels are centered on the feature they name. The crater Theophilus isn’t as prominent as it would have been 12 hours earlier, when it was nearer the terminator, the sunrise line. Search for it in the box above, right on this page, where I have more to say about it. It’s one of my favorite craters. Created using Stellarium, Libreoffice Draw, and GIMP.
Morning planets at 5:30 am tomorrow, August 4, 2022. With summer almost half over, the bright winter stars begin to appear in morning twilight along with the planets. Click on the image to enlarge it. The span of the planets from Venus to Saturn is 148 degrees. Click on the image to enlarge it. Created using Stellarium.
Views of Saturn, Jupiter, and Venus (north up) as they would be seen in a small telescope, with the same magnification, tomorrow morning at 5:30 am, August 4, 2022. I do not show planets less than 10 seconds of arc in diameter. Apparent diameters: Saturn 18.73″, its rings 43.63″; Jupiter 45.54″. Mars is not shown, its apparent diameter is 8.41″, 84.7% illuminated; Venus 10.64″, 93.2% illuminated. The ” symbol means seconds of arc (1/3600th of a degree.) Click on the image to enlarge it. 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 August 3, 2022. The night ends on the left with sunrise on the 4th. Notice that all the naked-eye planets except Mercury are in the morning sky now. That’s about to change in a week and a half, when Saturn moves into the evening sky when it reaches opposition from the Sun on the 14th. Click on the image to enlarge it. Created using my LookingUp program.
08/02/2022 – Ephemeris – Where did the Moon’s “seas” come from?
This is Ephemeris for Tuesday, August 2nd. Today the Sun will be up for 14 hours and 37 minutes, setting at 9:07, and it will rise tomorrow at 6:31. The Moon, 3 days before first quarter, will set at 11:37 this evening.
As the days progress to full moon on the 13th, the Moon will reveal its many maria or seas, as the first telescopic astronomers called these blemishes. Many have roughly circular outlines bounded by mountains. They have flat floors that are darker than the heavily cratered parts of the moon, and have very few craters on them. That means they were created after the major craters were made, and obliterated the craters beneath. The majority of the cratering came very early, as the Moon accreted from the material the was produced when a Mars sized protoplanet hit the early Earth about 4.51 billion years ago. That’s according to most planetary scientists. The maria are actually huge craters produced by large asteroids later, about 3.9 billion years ago.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.
Addendum
Lunar “seas” seen on a first quarter moon. Mare is Latin for sea. Sinus means bay. Created using Stellarium, GIMP and LibreOffice.
Lunar “seas” and some other prominent features labeled on the last quarter moon.
08/01/2022 – Ephemeris – Previewing August skies
This is Ephemeris for Monday, August 1st. Today the Sun will be up for 14 hours and 39 minutes, setting at 9:08, and it will rise tomorrow at 6:30. The Moon, halfway from new to first quarter, will set at 11:18 this evening.
Let’s look ahead at the month of August in the skies. Daylight hours will decrease from 14 hours and 39 minutes today to 13 hours 17 minutes on the 31st. The altitude of the Sun at local noon, that is degrees of angle above the southern horizon, will decrease from 63 degrees today to just over 53 degrees on the 31st. Straits area listeners can subtract one more degree from those angles. Local noon, when the Sun is due south, is about 1:43 p.m. The Perseid meteor shower will reach its peak all on the 12th. Unfortunately, the Moon will be only one day past full, so only the brightest meteors will be seen. However, for the next few days or so, the meteors can compete with the weaker moonlight of the waxing crescent Moon, though their numbers won’t be as high as it would be on a dark night of the peak.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.
Addendum
August Evening Star Chart
Star Chart for August 2022 (10 pm EDT, August 15, 2022). Click on image to enlarge it. Created using my LookingUp program.
Star Chart for August 2022 (10 pm EDT, August 15, 2022). Click on image to enlarge it. Created using my LookingUp program.
The planets and stars are plotted for the 15th at 10 p.m. EDT in the evening and 5 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). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.
Note the chart times 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.
August Morning Star Chart
Star Chart for August mornings, (5 a.m. EDT, August 15, 2022). Click on image to enlarge. Created using my LookingUp program.
Star Chart for August mornings, (5 a.m. EDT, August 15, 2022). Click on image to enlarge. Created using 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.
- Leaky dipper drips on Leo.
- 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.
- PerR is the radiant of the Perseid meteor shower (Peaks on the 12th)
Twilight Limits, Nautical and Astronomical
| EDT | |||||||
| Morning | Twilight | Evening | Twilight | Dark | Night | Moon | |
| Date | Astro. | Nautical | Nautical | Astro. | Start | End | Illum. |
| 2022-08-01 | 4h31m | 5h19m | 22h27m | 23h15m | 23h18m | 4h31m | 0.18 |
| 2022-08-02 | 4h33m | 5h21m | 22h25m | 23h13m | 23h37m | 4h33m | 0.27 |
| 2022-08-03 | 4h35m | 5h22m | 22h24m | 23h11m | 23h57m | 4h35m | 0.37 |
| 2022-08-04 | 4h37m | 5h24m | 22h22m | 23h09m | – | 4h37m | 0.47 |
| 2022-08-05 | 4h38m | 5h25m | 22h20m | 23h07m | 0h19m | 4h38m | 0.58 |
| 2022-08-06 | 4h40m | 5h27m | 22h19m | 23h05m | 0h46m | 4h40m | 0.69 |
| 2022-08-07 | 4h42m | 5h28m | 22h17m | 23h03m | 1h20m | 4h42m | 0.8 |
| 2022-08-08 | 4h44m | 5h30m | 22h15m | 23h00m | 2h05m | 4h44m | 0.88 |
| 2022-08-09 | 4h46m | 5h31m | 22h13m | 22h58m | 3h04m | 4h46m | 0.95 |
| 2022-08-10 | 4h48m | 5h33m | 22h11m | 22h56m | 4h16m | 4h48m | 0.99 |
| 2022-08-11 | 4h50m | 5h34m | 22h10m | 22h54m | – | – | 1 |
| 2022-08-12 | 4h52m | 5h36m | 22h08m | 22h52m | – | – | 0.98 |
| 2022-08-13 | 4h53m | 5h37m | 22h06m | 22h49m | – | – | 0.94 |
| 2022-08-14 | 4h55m | 5h38m | 22h04m | 22h47m | – | – | 0.87 |
| 2022-08-15 | 4h57m | 5h40m | 22h02m | 22h45m | 22h45m | 22h55m | 0.79 |
| 2022-08-16 | 4h59m | 5h41m | 22h00m | 22h43m | 22h43m | 23h16m | 0.7 |
| 2022-08-17 | 5h01m | 5h43m | 21h58m | 22h41m | 22h41m | 23h38m | 0.6 |
| 2022-08-18 | 5h02m | 5h44m | 21h56m | 22h38m | 22h38m | – | 0.5 |
| 2022-08-19 | 5h04m | 5h46m | 21h55m | 22h36m | 22h36m | 0h03m | 0.4 |
| 2022-08-20 | 5h06m | 5h47m | 21h53m | 22h34m | 22h34m | 0h32m | 0.31 |
| 2022-08-21 | 5h08m | 5h49m | 21h51m | 22h32m | 22h32m | 1h08m | 0.23 |
| 2022-08-22 | 5h10m | 5h50m | 21h49m | 22h29m | 22h29m | 1h52m | 0.15 |
| 2022-08-23 | 5h11m | 5h52m | 21h47m | 22h27m | 22h27m | 2h44m | 0.09 |
| 2022-08-24 | 5h13m | 5h53m | 21h45m | 22h25m | 22h25m | 3h43m | 0.04 |
| 2022-08-25 | 5h15m | 5h55m | 21h43m | 22h23m | 22h23m | 4h47m | 0.01 |
| 2022-08-26 | 5h16m | 5h56m | 21h41m | 22h20m | 22h20m | 5h16m | 0 |
| 2022-08-27 | 5h18m | 5h57m | 21h39m | 22h18m | 22h18m | 5h18m | 0.01 |
| 2022-08-28 | 5h20m | 5h59m | 21h37m | 22h16m | 22h16m | 5h20m | 0.04 |
| 2022-08-29 | 5h21m | 6h00m | 21h35m | 22h14m | 22h14m | 5h21m | 0.08 |
| 2022-08-30 | 5h23m | 6h02m | 21h33m | 22h12m | 22h12m | 5h23m | 0.15 |
| 2022-08-31 | 5h25m | 6h03m | 21h31m | 22h09m | 22h24m | 5h25m | 0.23 |
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
Aug 1 Mo Venus: 21.7° W
4 Th 12:58 am Mercury-Regulus: 0.7° N
5 Fr 7:06 am First Quarter
5 Fr 4:30 pm Moon Descending Node
6 Sa 5:33 am Venus-Pollux: 6.5° S
7 Su 4:29 am Moon-Antares: 2.8° S
9 Tu 2:36 am Moon South Dec.: 27° S
10 We 1:14 pm Moon Perigee: 359,800 km
11 Th 9:36 pm Full Sturgeon Moon
11 Th 11:55 pm Moon-Saturn: 3.9° N
12 Fr 9:20 pm Perseid Shower: ZHR = 90
14 Su 12:35 pm Saturn Opposition
15 Mo 5:37 am Moon-Jupiter: 1.9° N
17 We 12:02 pm Venus-Beehive: 0.9° S
18 Th 6:59 am Moon Ascending Node
19 Fr 12:36 am Last Quarter
19 Fr 6:32 am Moon-Pleiades: 3.4° N
19 Fr 8:16 am Moon-Mars: 2.9° S
20 Sa 4:36 am Mars-Pleiades: 5.6° S
22 Mo 11:08 am Moon North Dec.: 27.1° N
22 Mo 5:53 pm Moon Apogee: 405,400 km
23 Tu 8:17 pm Moon-Pollux: 2.3° N
24 We 9:46 pm Moon-Beehive: 3.8° S
25 Th 4:58 pm Moon-Venus: 4.7° S
27 Sa 4:17 am New Moon
27 Sa 11:59 am Mercury Elongation: 27.3° E
Sep 1 Th Venus: 13.6° W
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 August, 2022 Local time zone: EDT +-----------------------------------------------------------------------+ | DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM | | | RISE SET HOURS | END START |PHASE SET** TIME FRACTN| +=======================================================================+ |Mon 1| 06:29a 09:08p 14:39 | 10:23p 05:13a | Set 11:18p 17%| |Tue 2| 06:30a 09:07p 14:37 | 10:22p 05:14a | Set 11:37p 25%| |Wed 3| 06:31a 09:05p 14:34 | 10:20p 05:16a | Set 11:56p 34%| |Thu 4| 06:32a 09:04p 14:32 | 10:18p 05:17a | Set 12:19a 45%| |Fri 5| 06:33a 09:03p 14:29 | 10:17p 05:19a |F Qtr Set 12:45a 56%| |Sat 6| 06:34a 09:01p 14:27 | 10:15p 05:20a | Set 01:19a 67%| +------+-----------------------+----------------+-----------------------+ |Sun 7| 06:35a 09:00p 14:24 | 10:13p 05:22a | Set 02:04a 77%| |Mon 8| 06:37a 08:59p 14:21 | 10:11p 05:23a | Set 03:03a 86%| |Tue 9| 06:38a 08:57p 14:19 | 10:10p 05:25a | Set 04:15a 94%| |Wed 10| 06:39a 08:56p 14:16 | 10:08p 05:26a | Set 05:37a 98%| |Thu 11| 06:40a 08:54p 14:14 | 10:06p 05:28a |Full Rise 09:18p 100%| |Fri 12| 06:41a 08:53p 14:11 | 10:04p 05:29a | Rise 09:48p 99%| |Sat 13| 06:42a 08:51p 14:08 | 10:02p 05:31a | Rise 10:13p 95%| +------+-----------------------+----------------+-----------------------+ |Sun 14| 06:44a 08:50p 14:05 | 10:00p 05:32a | Rise 10:34p 88%| |Mon 15| 06:45a 08:48p 14:03 | 09:58p 05:34a | Rise 10:55p 80%| |Tue 16| 06:46a 08:46p 14:00 | 09:57p 05:35a | Rise 11:15p 71%| |Wed 17| 06:47a 08:45p 13:57 | 09:55p 05:37a | Rise 11:37p 62%| |Thu 18| 06:48a 08:43p 13:54 | 09:53p 05:38a | Rise 12:02a 52%| |Fri 19| 06:49a 08:41p 13:52 | 09:51p 05:40a |L Qtr Rise 12:32a 42%| |Sat 20| 06:51a 08:40p 13:49 | 09:49p 05:41a | Rise 01:08a 33%| +------+-----------------------+----------------+-----------------------+ |Sun 21| 06:52a 08:38p 13:46 | 09:47p 05:43a | Rise 01:51a 24%| |Mon 22| 06:53a 08:36p 13:43 | 09:45p 05:44a | Rise 02:43a 17%| |Tue 23| 06:54a 08:35p 13:40 | 09:43p 05:46a | Rise 03:42a 10%| |Wed 24| 06:55a 08:33p 13:37 | 09:41p 05:47a | Rise 04:46a 5%| |Thu 25| 06:57a 08:31p 13:34 | 09:39p 05:48a | Rise 05:52a 2%| |Fri 26| 06:58a 08:30p 13:31 | 09:37p 05:50a | Rise 07:00a 0%| |Sat 27| 06:59a 08:28p 13:28 | 09:35p 05:51a |New Set 09:04p 1%| +------+-----------------------+----------------+-----------------------+ |Sun 28| 07:00a 08:26p 13:25 | 09:33p 05:53a | Set 09:24p 3%| |Mon 29| 07:01a 08:24p 13:23 | 09:31p 05:54a | Set 09:43p 7%| |Tue 30| 07:02a 08:22p 13:20 | 09:29p 05:56a | Set 10:02p 13%| |Wed 31| 07:04a 08:21p 13:17 | 09:27p 05:57a | Set 10:23p 21%| +-----------------------------------------------------------------------+ * Nautical Twilight ** Moonrise or moonset, whichever occurs between sunrise and sunset
Generated using my LookingUp for DOS program.
Bob Moler's Ephemeris Blog 