06/02/2023 – Ephemeris – A South Pole adventure and a comet collision presentation – Tonight!
This is Bob Moler with Ephemeris for Friday, June 2nd. Today the Sun will be up for 15 hours and 22 minutes, setting at 9:22, and it will rise tomorrow at 5:59. The Moon, 1 day before full, will set at 5:14 tomorrow morning.
An Antarctic Odyssey: Winter-Over at South Pole Station will be the presentation by John W. Briggs, via Zoom, at tonight’s meeting of the Grand Traverse Astronomical Society at Northwestern Michigan College’s Rogers Observatory at 9 pm. John was a team member building a 24-inch infrared telescope and related experiments that were set up at the South Pole in time for him and colleagues to observe the July 1994, explosive crash of fragmented comet Shoemaker-Levy 9 into the planet Jupiter. There are two ways to attend: In person at the observatory, south of Traverse City on Birmley Road, or via Zoom with a link provided by the society’s website gtastro.org just prior to the meeting.
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

About the Program
An Antarctic Odyssey: Winter-Over at South Pole Station
A presentation via Zoom by John W. Briggs
Abstract:
In a lavishly illustrated presentation, John W. Briggs of New Mexico will describe his year-long experience living at the Geographic South Pole while working for the Center for Astrophysical Research in Antarctica. In preparation for this at Yerkes Observatory of the University of Chicago, John was a team member building a 24-inch infrared telescope and related experiments that were set up at the Pole in time for him and colleagues to observe the July 1994, explosive crash of fragmented comet Shoemaker-Levy 9 into the planet Jupiter.
John weathered the “winter-over” with 26 other members of the U.S. Antarctic Program in an experience that many believe approximates what life will be like someday at a lunar or Martian outpost. Once begun, South Pole winter-over is an irreversible commitment, since the Program’s special LC-130 ski planes can’t land in the winter temperatures — in 1994, sometimes as low as 107 degrees F. below zero (with windchill, as low as -180 degrees). John will delight the audience with his perspective on the total South Pole experience — the strange natural environment, the odd social atmosphere, and the challenging, ongoing science.
06/01/2023 – Ephemeris – Previewing June Skies
This is Bob Moler with Ephemeris for Thursday, June 1st. Today the Sun will be up for 15 hours and 20 minutes, setting at 9:21, and it will rise tomorrow at 5:59. The Moon, 2 days before full, will set at 4:43 tomorrow morning.
Let’s begin this program’s 49th trip around the Sun by previewing the skies of June. There will be a lot of Sun in June and very little night. The daylight hours will increase a bit from 15 hours and 20 minutes today to 15 hours and 34 minutes on the 21st, retreating back to 15 hours 31 minutes at month’s end. At this time of the year the sunset times for Ludington, Interlochen, Petoskey and Mackinaw City are very nearly the same. However, the sunrise times are at their most divergent. With Ludington’s sunrise being 14 minutes later than Mackinaw City’s. The altitude of the Sun above the southern horizon at local noon around 1:43 p.m. will hover around 68 to 69 degrees. Summer will start on the 21st at 10:58 a.m. Venus will look great in our skies and in telescopes this month.
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
June Evening Star Chart

The planets and stars are plotted for the 15th at 11 p.m. EDT in the evening and 4 a.m. for the morning chart. These are the chart times. Note that Interlochen/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 of 11 p.m. and 4 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, or 28 minutes. 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 for weekly positions.
June Morning Star Chart

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,
Twilight Limits, Nautical and Astronomical
EDT | |||||||
Morning | Twilight | Evening | Twilight | Dark | Night | Moon | |
Date | Astro. | Nautical | Nautical | Astro. | Start | End | Illum. |
2023-06-01 | 3h44m | 4h43m | 22h46m | 23h45m | – | – | 0.95 |
2023-06-02 | 3h43m | 4h42m | 22h48m | 23h47m | – | – | 0.99 |
2023-06-03 | 3h41m | 4h41m | 22h49m | 23h48m | – | – | 1.00 |
2023-06-04 | 3h40m | 4h40m | 22h50m | 23h50m | – | – | 0.98 |
2023-06-05 | 3h39m | 4h40m | 22h51m | 23h51m | – | – | 0.94 |
2023-06-06 | 3h38m | 4h39m | 22h52m | 23h53m | 23h53m | – | 0.87 |
2023-06-07 | 3h37m | 4h38m | 22h53m | 23h54m | 23h54m | 0h39m | 0.79 |
2023-06-08 | 3h36m | 4h38m | 22h53m | 23h55m | 23h55m | 1h18m | 0.68 |
2023-06-09 | 3h35m | 4h38m | 22h54m | 23h56m | 23h56m | 1h49m | 0.57 |
2023-06-10 | 3h35m | 4h37m | 22h55m | 23h58m | 23h58m | 2h13m | 0.46 |
2023-06-11 | 3h34m | 4h37m | 22h56m | 23h59m | 23h59m | 2h34m | 0.35 |
2023-06-12 | 3h33m | 4h36m | 22h57m | 0h00m | 0h00m | 2h54m | 0.25 |
2023-06-13 | 3h33m | 4h36m | 22h57m | 0h01m | 0h01m | 3h13m | 0.16 |
2023-06-14 | 3h32m | 4h36m | 22h58m | 0h01m | 0h01m | 3h32m | 0.09 |
2023-06-15 | 3h32m | 4h36m | 22h58m | 0h02m | 0h02m | 3h32m | 0.04 |
2023-06-16 | 3h32m | 4h36m | 22h59m | 0h03m | 0h03m | 3h32m | 0.01 |
2023-06-17 | 3h32m | 4h36m | 22h59m | 0h04m | 0h04m | 3h32m | 0.00 |
2023-06-18 | 3h32m | 4h36m | 23h00m | 0h04m | 0h04m | 3h32m | 0.01 |
2023-06-19 | 3h32m | 4h36m | 23h00m | 0h04m | 0h04m | 3h32m | 0.04 |
2023-06-20 | 3h32m | 4h36m | 23h00m | 0h05m | 0h05m | 3h32m | 0.08 |
2023-06-21 | 3h32m | 4h36m | 23h01m | 0h05m | 0h05m | 3h32m | 0.15 |
2023-06-22 | 3h32m | 4h37m | 23h01m | 0h05m | 0h28m | 3h32m | 0.22 |
2023-06-23 | 3h32m | 4h37m | 23h01m | 0h05m | 0h51m | 3h32m | 0.30 |
2023-06-24 | 3h33m | 4h37m | 23h01m | 0h05m | 1h11m | 3h33m | 0.39 |
2023-06-25 | 3h33m | 4h38m | 23h01m | 0h05m | 1h29m | 3h33m | 0.49 |
2023-06-26 | 3h34m | 4h38m | 23h01m | 0h05m | 1h46m | 3h34m | 0.59 |
2023-06-27 | 3h35m | 4h39m | 23h01m | 0h05m | 2h03m | 3h35m | 0.68 |
2023-06-28 | 3h35m | 4h39m | 23h01m | 0h04m | 2h22m | 3h35m | 0.78 |
2023-06-29 | 3h36m | 4h40m | 23h01m | 0h04m | 2h43m | 3h36m | 0.86 |
2023-06-30 | 3h37m | 4h40m | 23h00m | 0h03m | 3h10m | 3h37m | 0.93 |
The twilight calendar was generated using Cartes du Ciel (Sky Charts), with some corrections.
See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.
NASA Calendar of Planetary Events
Date Time Event Jun 1 Th Venus: 45.4° E 1 Th 2:22 am Moon Descending Node 1 Th 11:30 pm Mars-Beehive: 0.1° S 3 Sa 5:19 pm Moon-Antares: 1.6° S 3 Sa 11:42 pm Full Strawberry Moon 4 Su 6:59 am Venus Elongation: 45.4° E 5 Mo 12:21 pm Moon South Dec.: 27.9° S 6 Tu 7:07 pm Moon Perigee: 364,900 km 9 Fr 4:19 pm Moon-Saturn: 3° N 10 Sa 3:31 pm Last Quarter 11 Su 1:50 pm Mercury-Pleiades: 6.2° S 13 Tu 7:05 am Venus-Beehive: 0.5° N 13 Tu 8:05 pm Moon Ascending Node 14 We 2:33 am Moon-Jupiter: 1.6° S 15 Th 8:47 pm Moon-Pleiades: 2° N 16 Fr 4:18 pm Mercury-Aldebaran: 4.3° N 18 Su 12:37 am New Moon 18 Su 5:07 pm Moon North Dec.: 27.8° N 20 Tu 5:10 am Moon-Pollux: 1.9° N 21 We 6:38 am Moon-Beehive: 4° S 21 We 10:58 am Summer Solstice 21 We 8:47 pm Moon-Venus: 4.1° S 22 Th 6:09 am Moon-Mars: 4.2° S 22 Th 2:31 pm Moon Apogee: 405,400 km 26 Mo 3:50 am First Quarter 28 We 8:22 am Moon Descending Node Jul 1 Sa Venus: 41.7° E
Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.
Sun and Moon Rising and Setting Events
LU Ephemeris of Sky Events for Interlochen/TC June, 2023 Local time zone: EDT +-----------------------------------------------------------------------+ | DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM | | | RISE SET HOURS | END START |PHASE SET** TIME FRACTN| +=======================================================================+ |Thu 1| 06:00a 09:21p 15:20 | 10:44p 04:37a | Set 04:43a 94%| |Fri 2| 05:59a 09:22p 15:22 | 10:45p 04:36a | Set 05:14a 98%| |Sat 3| 05:59a 09:22p 15:23 | 10:46p 04:35a |Full Rise 09:27p 100%| +------+-----------------------+----------------+-----------------------+ |Sun 4| 05:59a 09:23p 15:24 | 10:47p 04:35a | Rise 10:42p 99%| |Mon 5| 05:58a 09:24p 15:25 | 10:48p 04:34a | Rise 11:47p 95%| |Tue 6| 05:58a 09:25p 15:26 | 10:49p 04:33a | Rise 12:39a 89%| |Wed 7| 05:57a 09:25p 15:27 | 10:50p 04:33a | Rise 01:18a 80%| |Thu 8| 05:57a 09:26p 15:28 | 10:51p 04:32a | Rise 01:48a 70%| |Fri 9| 05:57a 09:27p 15:29 | 10:52p 04:32a | Rise 02:13a 59%| |Sat 10| 05:57a 09:27p 15:30 | 10:53p 04:31a |L Qtr Rise 02:34a 48%| +------+-----------------------+----------------+-----------------------+ |Sun 11| 05:56a 09:28p 15:31 | 10:53p 04:31a | Rise 02:53a 37%| |Mon 12| 05:56a 09:28p 15:31 | 10:54p 04:31a | Rise 03:13a 27%| |Tue 13| 05:56a 09:29p 15:32 | 10:55p 04:30a | Rise 03:34a 18%| |Wed 14| 05:56a 09:29p 15:33 | 10:55p 04:30a | Rise 03:59a 10%| |Thu 15| 05:56a 09:30p 15:33 | 10:56p 04:30a | Rise 04:28a 5%| |Fri 16| 05:56a 09:30p 15:33 | 10:56p 04:30a | Rise 05:04a 2%| |Sat 17| 05:56a 09:30p 15:34 | 10:57p 04:30a | Rise 05:49a 0%| +------+-----------------------+----------------+-----------------------+ |Sun 18| 05:56a 09:31p 15:34 | 10:57p 04:30a |New Set 10:36p 1%| |Mon 19| 05:56a 09:31p 15:34 | 10:57p 04:30a | Set 11:22p 3%| |Tue 20| 05:56a 09:31p 15:34 | 10:58p 04:30a | Set 11:58p 8%| |Wed 21| 05:57a 09:32p 15:34 | 10:58p 04:30a | Set 12:27a 13%| |Thu 22| 05:57a 09:32p 15:34 | 10:58p 04:31a | Set 12:51a 20%| |Fri 23| 05:57a 09:32p 15:34 | 10:58p 04:31a | Set 01:11a 28%| |Sat 24| 05:57a 09:32p 15:34 | 10:58p 04:31a | Set 01:29a 37%| +------+-----------------------+----------------+-----------------------+ |Sun 25| 05:58a 09:32p 15:34 | 10:58p 04:32a | Set 01:45a 47%| |Mon 26| 05:58a 09:32p 15:33 | 10:58p 04:32a |F Qtr Set 02:02a 57%| |Tue 27| 05:59a 09:32p 15:33 | 10:58p 04:33a | Set 02:21a 66%| |Wed 28| 05:59a 09:32p 15:32 | 10:58p 04:33a | Set 02:43a 76%| |Thu 29| 05:59a 09:32p 15:32 | 10:58p 04:34a | Set 03:10a 84%| |Fri 30| 06:00a 09:32p 15:31 | 10:57p 04:34a | Set 03:45a 92%| +-----------------------------------------------------------------------+ * Nautical Twilight ** Moonrise or moonset, whichever occurs between sunrise and sunset
Generated using my LookingUp for DOS program.
05/31/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Bob Moler with Ephemeris for Wednesday, May 31st. Today the Sun will be up for 15 hours and 19 minutes, setting at 9:20 pm, and it will rise tomorrow at 6 am. The Moon, 3 days before full, will set at 4:19 am tomorrow.
Let’s find where the naked-eye planets have wandered off to this week. Venus is our blazing Evening Star, seen in the west all evening. It will set after midnight. The red planet Mars has moved into Cancer, and is seen above and left of Venus by 12 degrees, or a bit more than the width of one’s fist held at arm’s length. Venus is closing the gap between them, but will never quite reach Mars while they are in the evening sky. The closest they will get is three and a half degrees or 7 moon diameters apart, before Venus pulls back toward the Sun faster than Mars will. In the morning, Saturn will be visible low in the southeast at 5 am, rising at 2:28 am. Jupiter makes its morning appearance and is low in the east-northeast at that hour, rising at 4:27 am.
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




05/30/2023 – Ephemeris – The Terminator… No, not Arnold Swartzenegger
This is Ephemeris for Tuesday, May 30th. Today the Sun will be up for 15 hours and 17 minutes, setting at 9:19, and it will rise tomorrow at 6:01. The Moon, 3 days past first quarter, will set at 3:59 tomorrow morning.
The Moon tonight is getting to be a fatter and fatter gibbous phase, until Saturday, when it will be full. The Moon will be blindingly bright in telescopes of low magnification. As always the case with the Moon, the most detail is seen near the terminator. The terminator, in the case of the waxing moon, is the sunrise line. After full moon, the terminator becomes the sunset line. This is where the shadows are longest, showing the detail of the craters. Farther from the terminator, where the Sun is higher in the Moon’s sky, shadows are short or nonexistent. Giving the surface a flat appearance. Even lacking wind and water, there is still erosion on the Moon, coming from meteoroid and asteroid impacts and their ejecta. And the breakdown of rocks due to the extreme day-night temperature swings.
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

05/29/2023 – Ephemeris – Sinus Iridium, a hook into night
This is Bob Moler with Ephemeris for Memorial Day, Monday, May 29th. Today the Sun will be up for 15 hours and 16 minutes, setting at 9:18, and it will rise tomorrow at 6:01. The Moon, 2 days past first quarter, will set at 3:41 tomorrow morning.
Let’s look at the Moon tonight. One of my favorite formations is coming into light. It is called Sinus Iridium or Bay of Rainbows. Sorry, there’s no color here. But if caught at right time, and tonight’s the night, this ruined crater will appear as a hook out into night off the upper left edge of the moon. Officially it’s a bay to the Sea of Showers or Mare Imbrium. The north edge of the bay are mountains called the Jura Mountains. The south edge disappears into Mare Imbrium. The floor of the Sinus Iridium is about twelve hundred feet lower than Mare Imbrium. The transition is gradual because it isn’t very noticeable. The formation is large enough to be seen in binoculars. Sinus Iridium is 242 miles wide, a good tenth the diameter of the Moon itself.
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

05/26/2023 – Ephemeris – Sun & Star Party tomorrow at the Sleeping Bear Dunes National Lakeshore
This is Bob Moler with Ephemeris for Friday, May 26th. Today the Sun will be up for 15 hours and 11 minutes, setting at 9:15, and it will rise tomorrow at 6:03. The Moon, 1 day before first quarter, will set at 2:48 tomorrow morning.
Tomorrow, the Sleeping Bear Dunes National Lakeshore and the Grand Traverse Astronomical Society will host a Sun and Star Party at the Dune Climb area of the park. There will be a solar viewing period from 5 pm to about 7 pm. The society has two hydrogen alpha solar telescopes to view the Sun’s chromosphere and prominences. Plus, some members also have solar scopes and white light filtered telescopes to view sunspots on the face of the Sun. Night viewing will start at 9 pm, with the Moon and Venus featured, along with the brighter telescopic wonders of late spring. There will be a pass of the International Space Station from 10:11 to 10:18 pm. The rangers will have an alternate program if it’s cloudy.
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

A Sun Party at the Dune Climb. Credit: Eileen Carlisle.

Preparing to start the May star party, several years ago at the Dune Climb. A few of the telescopes are visible, including the GTAS 25″ “Emmettron” telescope at the far right background. Credit: Eileen Carlisle.
05/25/2023 – Ephemeris – NASA awards contracts for a second lunar lander
This is Ephemeris for Thursday, May 25th. Today the Sun will be up for 15 hours and 9 minutes, setting at 9:14, and it will rise tomorrow at 6:04. The Moon, 2 days before first quarter, will set at 2:26 tomorrow morning.
A week ago, NASA announced that the contract for the second Artemis moon lander would go to a group of companies headed by Blue Origin for 3.4 billion dollars. Unlike Apollo, the rocket that sens crews to the Moon will not contain a moon landing craft. It will be sent out separately before the crew. SpaceX’s Lunar Starship will be used on the first two landings, for Artemis III and IV, while the Blue Origin lander will be used for Artemis V, sometime around 2029 or later. Little detail has been released about the lander, except for an artist’s rendering. It appears to be shorter than the Boeing lander first proposed, which would require an astronaut to climb up and down a very long ladder. SpaceX’s Starship would be taller still, but will have an elevator on the side.
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

NASA picks Bezos’ Blue Origin to build second lunar lander. The crew compartment is on the bottom, allowing for a shorter ladder to the surface. The liquid oxygen (LOX) and hydrogen (LH) tanks are on top. The LH tank is on top with sun shields, with the LOX tank below. I’m guessing here, since very little information has been released. Credit: NASA.
The craft is officially known as the Human Landing System (HLS).
05/24/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Ephemeris for Wednesday, May 24th. Today the Sun will be up for 15 hours and 7 minutes, setting at 9:13, and it will rise tomorrow at 6:05. The Moon, 3 days before first quarter, will set at 1:59 tomorrow morning.
Let’s find where the naked-eye planets have wandered off to this week. Venus is our blazing Evening Star, seen in the west all evening. It will set after midnight. The red planet Mars will appear below the Moon tonight. It has moved into Cancer, and is seen above and left of Venus by 14 degrees, or one and a half times the width of one’s fist held at arm’s length. Venus is closing the gap between them, but will never quite reach Mars while they are in the evening sky. The closest they will get is three and a half degrees or 7 moon diameters apart, before Venus pulls back toward the Sun faster than Mars will. In the morning, Saturn will be visible and low in the southeast at 5 am, rising at 2:47 am. Jupiter makes its morning appearance and is very low in the east-northeast at that hour.
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

Evening planets and the Moon at 10 pm tonight, May 24, 2023. Created using Stellarium, LibreOffice Draw and GIMP.

5 day old Moon with selected features labeled for May 24, 2023, at 10 pm. Created using Stellarium, LibreOffice and GIMP.

Saturn and Jupiter in early morning twilight at 5:00 am tomorrow, May 25, 2023. Created using Stellarium.

Telescopic Venus, Saturn and Jupiter (north up) as they would be seen in a small telescope, with the same magnification. Apparent diameters: Venus 21.03″ and is 55.4% illuminated; Saturn 16.96″, its rings 39.52″; Jupiter 34.07″. Mars, too small to be represented here, is 4.81″ in diameter. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).
05/23/2023 – Ephemeris – Let’s observe the four-day-old Moon
This is Bob Moler with Ephemeris for Tuesday, May 23rd. Today the Sun will be up for 15 hours and 5 minutes, setting at 9:12, and it will rise tomorrow at 6:06. The Moon, halfway from new to first quarter, will set at 1:25 tomorrow morning.
The four-day-old Moon has uncovered a sea below Mare Crisium or Sea of Crises. It’s Mare Fecunditatis, or the Sea of Fertility. It appears to have been created in the first period of the Moon’s history from 4.55 billion years to 3.92 billion years ago, called the pre- Nectarian geological period, while Mare Crisium is a bit younger, from 3.92 to 3.85 billion years ago, the Nectarian period. Both periods were named for Mare Nectaris, or Sea of Nectar, a small sea next to the Sea of Fertility just coming into sunlight. There are two small, but remarkable craters in the Sea of Fertility called Messier and Messier A which appear to be the result of a double asteroid impact, where it looks like the Moon was struck at a low angle, sending debris out in one direction.
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

4 day old Moon with selected features labeled for May 23, 2023, at 10 pm. Created using Stellarium, LibreOffice Draw and GIMP.
05/22/2023 – Ephemeris – Exploring the three-day-old Moon
This is Ephemeris for Monday, May 22nd. Today the Sun will be up for 15 hours and 4 minutes, setting at 9:11, and it will rise tomorrow at 6:06. The Moon, 3 days past new, will set at 12:43 tomorrow morning.
Tonight we will see the three-day-old moon low in the west. It may exhibit earthshine. That is, its night side will be illuminated by the Earth’s day side. Just as the earthly night is illuminated by moonlight, especially when the Moon is near full, the night side of the Moon, when near new, is illuminated by earthlight. In binoculars or telescope, the large dark spot, on the Moon’s right edge, is Mare Crisium, or Sea of Crises. The large crater below and a bit left of that sea is Langrenus, named after a 17th century Belgian engineer and mathematician who produced the first lunar map with nomenclature. Langrenus appears as a bright spot as the Sun rises higher for it. Also check out the south end of the cusp of the crescent for a lone mountain peak catching the Sun.
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.