08/09/2022 – Ephemeris – Artemis I mission could launch by the end of the month

August 9, 2022 Leave a comment

This is Bob Moler with Ephemeris for Tuesday, August 9th. Today the Sun will be up for 14 hours and 19 minutes, setting at 8:57, and it will rise tomorrow at 6:39. The Moon, 2 days before full, will set at 4:15 tomorrow morning.

NASA has announced the launch date for the Artemis 1 uncrewed mission to the Moon. It’s August 29th. Or, in NASAspeak, NET (not earlier than) August 29th. Being the first launch of a new vehicle, they probably won’t launch on that day, due to encountered problems. Their second wet dress rehearsal still fell a few seconds short of the programmed end time, just before the main engines would be lit. If Artemis can’t launch on the 29th, the next date to go will be September 2nd, The four-day wait is because in that period the Orion capsule would spend too much time in the Earth’s shadow and without sunlight for its solar panels, depleting its batteries, on its way out to the Moon. The next opportunity after that would come on the 5th. Then a long wait til the 20th.

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

Simulated Artemis launch from Launch Pad 39B

Simulated Artemis launch from Launch Pad 39B as it would be seen from offshore. Credit NASA.

Artemis I mission overview

Major mission milestones. Click on the image to enlarge. Credit: NASA

Ephemeris Extra – Wandering through Sagittarius

August 8, 2022 Leave a comment

Annotated Sagittarius photograph

Sagittarius in a short time exposure with added annotations. The “M” designations are objects in Charles Messier’s catalog created in the latter half of the 18th century. LSSC is the Large Sagittarius Star Cloud, SSSC is the Small Sagittarius Star Cloud. Credit Bob Moler.

Sagittarius is seen low in the south in August. It’s between Scorpius to the west, and Capricornus, rising in the southeast. The name Sagittarius simply means archer. It doesn’t describe the fact that the archer isn’t just any old bloke with a bow and arrow, but is, indeed, a centaur, one of the two in the list of constellations. The other, Centaurus, is too far south to be seen from Michigan. And whose brightest star, Alpha Centauri, is in the closest star system to our solar system.
Centaurs, as a rule, were a rowdy bunch, the ancient Greek equivalent to a modern motorcycle gang. However, the centaur depicted by Sagittarius can be thought to be Chiron, though it can also be ascribed to Centaurus. Chiron was learned, a teacher and physician. I’ve noticed that in some artist’s depictions of Chiron, he is teaching Achilles how to use the bow and arrow. He also taught medicine to Asclepius, the great physician, who is seen in the heavens as the constellation Ophiuchus, above and right of Sagittarius.
What most of us see in the stars here is maybe a bow drawn to shoot at the heart of Scorpius, or a stout little teapot as in the children’s song. It even has the Milky Way seeming to rise from the spout like steam. The teapot rises in the southeast as if standing upright, and as the night wears on, it rises and move westward, slowly tilting to pour out its tea on the southwestern horizon.
The area of Sagittarius and the Milky Way is a fantastic part of the sky to explore with binoculars or a low power telescope on moonless nights. At the head of this post is a photograph of Sagittarius and the Milky Way taken from my home, with lines and labels. It’s somewhat spoiled by the sky glow from Chum’s Corner, a small commercial center 3.6 miles away, from the lower left. Most binoculars will show open or galactic star clusters as fuzzy spots like nebulae, which are fuzzy because they are clouds. The older globular star clusters require larger amateur telescopes to resolve.
I’ve only pointed out one in the image, that’s M22, whose designation, we have fun with at star parties at the Sleeping Bear Dunes National Lakeshore, since the road M22 runs through the park. Which came first? That’s easy, Charles Messier cataloged his 22nd object before Michigan was a state or even had roads. Well, maybe there were a few, around Detroit and Sault Ste. Marie, back when the major “roads” were the Great Lakes, and the rest Indian trails.
A telescope, even a small one, will resolve open clusters, showing individual stars. Telescopes will show the shapes of nebulae if they are bright enough.
One nebula with a distinctive shape is M17. The descriptive name I first knew it as was the Omega Nebula, and also the Horseshoe Nebula. To me, it never looked like either. It looked like a check mark, or a somewhat short necked swan. And it also goes by those names too. The planetarium program I use a lot, Stellarium, also calls it the Lobster nebula. I’m not much for seafood, but it doesn’t look like a lobster, or maybe I’m not hungry enough.
M16, is the Eagle Nebula. It has an associated star cluster. My eyes are drawn to the star cluster. The nebulosity is very faint, and I usually can’t see it. Part of the nebula was famously photographed by the Hubble Space Telescope and called the Pillars of Creation. In actuality, they are the Pillars of Destruction as they are being blown away by the stellar winds of the star cluster.
M8 is the Lagoon Nebula, it also has an associated star cluster. In telescopes, it is crossed by a narrow dust cloud suggestive of a lagoon. Nearby M20 is the Trifid nebula, which has a low surface brightness and can easily be missed. It is crossed by three narrow dust clouds dividing it into three, or on closer inspection, four wedges.
These just scratch the surface. So with or without optical aid wander through the celestial wonders and star clouds of Sagittarius. You have August and September to do it in the evening before they set for another year.

Based on an article I wrote for the August 2022 issue of the Stellar Sentinel, the Newsletter of the Grand Traverse Astronomical Society.

08/08/2022 – Ephemeris – The ages of the features on the Moon

August 8, 2022 Leave a comment

This is Ephemeris for Monday, August 8th. Today the Sun will be up for 14 hours and 21 minutes, setting at 8:59, and it will rise tomorrow at 6:38. The Moon, halfway from first quarter to full, will set at 3:03 tomorrow morning.

Looking up at the gibbous Moon tonight, at the various patches of light and dark gray. Did you ever wonder how planetary scientists could piece together the history of our satellite? Other than studying photographs of the Moon, we have samples to study brought back be the Apollo astronauts, the Russians, and most recently the Chinese. We have the Lunar Reconnaissance Orbiter, which has photographed, and otherwise studied the surface and environment of the moon up close for 13 years so far. Something of the Moon’s history can be seen even with a small telescope. Craters showing rays, that has bright ejecta are newer than craters with faint ejecta, which are newer than craters with no ejecta marks. And so on.

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

Ages of selected lunar features

Names and ages of selected lunar features via GIF animation for the Moon as it will appear tonight, August 8, 2022. Ages are in billions of years, with the oldest features being created 4.55 billion years ago. Source: Virtual Moon Atlas application. It can be downloaded from a link from the right panel of this page. GIF created using GIMP and LibreOffice Draw apps.

Here’s a link to the Planetary Society article Relative and absolute ages in the histories of Earth and the Moon: The Geologic Time Scale by Emily Lakdawalla: https://www.planetary.org/articles/09301225-geologic-time-scale-earth-moon

Categories: Ephemeris Program, The Moon Tags:

08/05/2022 – Ephemeris – Star Party tonight at the Joseph H. Rogers Observatory

August 5, 2022 Leave a comment

This is Bob Moler with Ephemeris for Friday, August 5th. Today the Sun will be up for 14 hours and 29 minutes, setting at 9:03, and it will rise tomorrow at 6:34. The Moon, at first quarter today, will set at 12:45 tomorrow morning.

Tonight, the Grand Traverse Astronomical Society will host a star party at Northwestern Michigan College’s Rogers Observatory from 10 pm to midnight, if it’s clear. The first quarter Moon, and the planet Saturn, will be seen. Toward the end of the evening, Jupiter will make an appearance. Saturn is always magnificent with its rings, and Jupiter with its moons and cloud bands. Also, visible will be some brighter wonders beyond the solar system. Nebulae, which are clouds of gas, and great clusters of stars. Views from one of the observatory telescopes will be available via Zoom, link at gtastro.org. Some society members will also bring their telescopes for displaying the sky for attending visitors. The observatory is located south of Traverse City on Birmley Road. The approach to the observatory from Keystone Road from the south may be blocked by the construction of a roundabout at the Keystone-Cass Rd intersection.

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

Star party at the NMC Observatory

Telescopes set up by members of the Grand Traverse Astronomical Society at the back of Northwestern Michigan College’s Joseph H. Rogers Observatory on August 3, 2018. Credit mine.

This may be the first time since 2019 that members will set their telescopes out behind the observatory for a star party. The telescope in the small dome is the one used for Zoom views of the Moon and possibly Saturn. Saturn will be blocked by trees for most of the evening, except from the observatory dome which is high enough, so Saturn will clear the trees sooner.

The sky is forecast to be partly cloudy, whatever that means. The Clear Sky Chart for the observatory shows that it will be clear. There is also a possibility of haze from the forest fires out west, dimming the sky and making observation of deep sky objects more difficult.

Events of the evening:

The first quarter Moon will already be up and will set at 12:45 am
9:03 pm – sunset
9:24 pm – Saturn rises*
10:20 pm – Nautical twilight ends
11:02 pm – Jupiter rises*
11:07 pm – Astronomical twilight ends

* It may be at least a half hour after rising before the image of these planets become half way sharp, due to the great amount of atmosphere we are looking through to see them. The higher in the sky they are, the better they will appear.

08/04/2022 – Ephemeris – The Late Heavy Bombardment

August 4, 2022 Comments off

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

Tonights Moon with labels

First quarter Moon with prominent seas labeled. Created using Stellarium, GIMP and LibreOffice.

Nice model infographic

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

August 3, 2022 Comments off

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 Moon annotated

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 and winter stars

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.

Telescopic views of Saturn, Jupiter, and Venus

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).

Planets and the Moon on a single night

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?

August 2, 2022 Comments off

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

Tonights Moon with labels

Lunar “seas” seen on a first quarter moon. Mare is Latin for sea. Sinus means bay. Created using Stellarium, GIMP and LibreOffice.

Last quarter moon with labels

Lunar “seas” and some other prominent features labeled on the last quarter moon.

08/01/2022 – Ephemeris – Previewing August skies

August 1, 2022 Comments off

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

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

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.

07/29/2022 – Ephemeris – The celestial Sand Hill Crane

July 29, 2022 Comments off

This is Ephemeris for Friday, July 29th. Today the Sun will be up for 14 hours and 46 minutes, setting at 9:12, and it will rise tomorrow at 6:26. The Moon, 1 day past new, will set at 10:14 this evening.

Let’s look again at the constellation called Cygnus the swan and the informal constellation or asterism made from most of its stars, the Northern Cross. Cygnus is the official International Astronomical Union constellation name. However, the indigenous Anishinaabe people of our area had another bird in mind when seeing these stars, which are now fairly high in the east in the evening: Ajijaak, (pronounced a-ji-jock) a Sand Hill crane. While the swan is flying, neck outstretched to the south through the Milky Way, the crane is flying northward with its long legs trailing behind. The bright star Deneb is at his head. Where I live, I see and hear the cranes with their creaking-door-like calls, and see a pair from time to time in a field south of where I live.

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

Swan and the Crane constellations

The IAU Cygnus the swan and the Anishinaabe Ajijaak the Sand Hill crane constellations demonstrated via an animated GIF image. Credit Stellarium (both star lore images are embedded in Stellarium). The Anishinaabe image is from Ojibwe Giizhig Anung Masinaaigan – Ojibiwe Sky Star Map created by A. Lee, W. Wilson, and C. Gawboy.

07/28/2022 – Ephemeris – Why don’t we have solar eclipses every new moon?

July 28, 2022 Comments off

This is Bob Moler with Ephemeris for Thursday, July 28th. Today the Sun will be up for 14 hours and 48 minutes, setting at 9:13, and it will rise tomorrow at 6:25. The Moon is new today, and won’t be visible.

The actual time when the moon is New will be 1:55 pm. The Moon will not eclipse the Sun this time. Why? Because the Moon is nearly 5 degrees, or 10 moon-diameters, north of the Sun. If the Moon orbited the Earth nearly in the same plane that the Earth orbited the Sun, we could have solar eclipses for somewhere on the Earth every new moon. As it is, the Moon orbits the Earth with about a 5-degree tilt to the Earth’s orbit of the Sun. So we get eclipse opportunities of eclipses about one in six new moons for solar eclipse and about the same for full moons and lunar eclipses. Of course, one has to be at the proper location to see them. If the Moon orbited the Earth over the Earth’s equator, like many other moons of other planets, eclipses would be much more rare and only occur around the equinoxes.

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 Sun and Moon at New Moon 7/28/2022

The Sun and Moon at New Moon at 1:55 pm today, seen as if the Earth had no atmosphere and one could see the Sun and stars at the same time. The orange line is the path of the Sun in the sky, called the ecliptic. The red line is the orbit of the Moon. Created using Stellarium.

Sun and Moon's orbits on the celestial sphere

Earth centered (geocentric) diagram of the heavens called the celestial sphere, showing the apparent orbits of the Sun and Moon. The Moon’s orbit has about a 5-degree tilt (exaggerated here) to the Sun’s apparent orbit, which we call the ecliptic. Solar eclipses occur when the new moon and Sun are near a node. Lunar eclipses occur when the full moon and Sun are near opposite nodes. My diagram.

The orbit of the Moon precesses, so the line of the nodes regresses, that is slowly rotating clockwise, backwards to the motion of the Sun and Moon (and all the rest of the planets), one rotation in 18.6 years.