Archive
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




05/24/2023 – 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).
05/17/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Bob Moler with Ephemeris for Wednesday, May 17th. Today the Sun will be up for 14 hours and 53 minutes, setting at 9:06, and it will rise tomorrow at 6:11. The Moon, 2 days before new, will rise at 5:30 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 has moved into Cancer, left of the namesake stars of the Gemini twins, with Pollux closest to Mars and Castor farther right. Mars is above and left of Venus by 18 degrees, or a bit less than two 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, low in the east-southeast by 5 am, rising at 3:18 am. This morning, the Moon is covering or occulting Jupiter. Daylight is making this a telescopic event.
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 with the stars at 10 pm tonight, May 17, 2023. Created using Stellarium and LibreOffice Draw.

Telescopic Venus and Saturn (north up) as they would be seen in a small telescope, with the same magnification. Apparent diameters: Venus 19.65″ and is 58.9% illuminated; Saturn 16.77″, its rings 39.05″. Mars, too small to be represented here, is 4.96″ in diameter. Created using Cartes du Ciel (Sky Charts).
05/10/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Bob Moler with Ephemeris for Wednesday, May 10th. Today the Sun will be up for 14 hours and 37 minutes, setting at 8:58, and it will rise tomorrow at 6:19. The Moon, 2 days before last quarter, will rise at 2:42 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 is in Gemini, left and a bit below Pollux, the leftmost of the namesake stars of the twins, with Castor on the right. Mars is above and left of Venus. By 20 degrees, or two 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 east-southeast by 5 am, rising at 3:37 am. Both Jupiter and Mercury are too close to the direction of the Sun to be seen.
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

Venus and Mars among the setting winter stars at 10 pm tonight, May 10, 2023. Created using Stellarium, LibreOffice Draw and GIMP.

Saturn and the Moon in the morning sky at 5:30 am. Note the Sagittarius’ Teapot asterism on the right. Created using Stellarium.

Waning gibbous Moon animation with selected features labeled. Labels are centered on their feature. Created using Stellarium, LibreOffice, and GIMP.

Telescopic Venus and Saturn (north up) as they would be seen in a small telescope, with the same magnification tonight, the night of May 10/11, 2023. Apparent diameters: Venus 18.45″ and is 62.1% illuminated; Saturn 16.58″, its rings 38.61″. Mars, too small to be represented here, is 5.12″ in diameter. Both Venus and Saturn are getting larger as they approach us. Created using Cartes du Ciel (Sky Charts).
05/03/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Ephemeris for Wednesday, May 3rd. Today the Sun will be up for 14 hours and 19 minutes, setting at 8:49, and it will rise tomorrow at 6:28. The Moon, 2 days before full, will set at 5:56 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 is in Gemini, below Pollux, left of Castor, the namesake stars of the twins. Mars is above and left of Venus by 24 degrees, or almost two 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. Saturn, low in the southeast by 6 am, is emerging from morning twilight, rising at 4:07 am. Both Jupiter and Mercury are too close to the direction of the Sun to be seen.
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

Venus and Mars among the setting winter stars tonight, at 10 pm, May 3rd, 2023. Click or tap on the image to enlarge it. Created using Stellarium, Libreoffice Draw and GIMP.

Moon 2 days before full, annotated for 10 pm, May 3, 2023. Created using Stellarium, LibreOffice Draw, and GIMP.

Telescopic Venus and Saturn (north up) as they would be seen in a small telescope, with the same magnification. Apparent diameters: Venus 17.43″ and is 65.2% illuminated; Saturn 16.39″, its rings 38.19″. Mars, too small to be represented here, is 5.30″ in diameter. Created using Cartes du Ciel (Sky Charts).
04/28/2023 – Ephemeris – International Astronomy Day is tomorrow
This is Bob Moler with Ephemeris for Arbor Day, Friday, April 28th. Today the Sun will be up for 14 hours and 6 minutes, setting at 8:43, and it will rise tomorrow at 6:36. The Moon, 1 day past first quarter, will set at 4:23 tomorrow morning.
Tomorrow is International Astronomy Day. The Grand Traverse Astronomical Society (GTAS) will celebrate the event with a Sun and Star Party at the Dune Climb area of the Sleeping Bear Dunes National Lakeshore. There will be a solar viewing period from 6 pm to about 7:30 pm or so, when the Sun will set over the dune. The society has two hydrogen alpha solar telescopes, and members have another two, to view the Sun’s chromosphere and prominences. Plus, other members have 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 spring. But only if the skies are clear or mostly clear.
The next GTAS event at the Sleeping Bear Dunes will be Saturday, May 27th, with a program like this Saturday’s. What we call a Sun ‘n Star Party.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –4 hours). They may be different for your location.
Addendum
04/27/2023 – Ephemeris – Astronomy Day is this Saturday, April 29, 2023
This is Bob Moler with Ephemeris for Thursday, April 27th. Today the Sun will be up for 14 hours and 3 minutes, setting at 8:42, and it will rise tomorrow at 6:37. The Moon, at first quarter today, will set at 3:59 tomorrow morning.
It is the latter part of April or first part of May that the spring celebration of International Astronomy Day occurs. It’s generally the Saturday closest to first quarter moon. That puts it to this Saturday, two days hence. This year, the Grand Traverse Astronomical Society will celebrate the event with a Sun and Star Party at the Sleeping Bear Dunes National Lakeshore, more specifically at the Dune Climb. More on the schedule tomorrow, but only if weather permits. The time around first quarter is the best time to view the Moon, if you aren’t out to view a specific lunar feature. The rugged highlands to the south and the smooth maria or seas to the north are seen at their best near the sunrise line, we call the terminator, due to the long shadows that are cast.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –4 hours). They may be different for your location.
Addendum

The Moon for Astronomy Day, 2023, two days after first quarter or 9 days old. Some of the more prominent features labeled. Created using Virtual Moon Atlas, GIMP and LibreOffice Draw.
Translations of some lunar feature names according to Virtual Moon Atlas
Lacus Somniorum – Lake of Dreams
Mare Crisium – Sea of Crises
Mare Frigoris – Sea of Cold
Mare Humorum – Sea of Moisture
Mare Imbrium – Sea of Showers
Mare Nubium – Sea of Clouds
Mare Serenitatis – Sea of Serenity
Mare Tranquillitatis – Sea of Tranquility
Mare Vaporum – Sea of Vapors
Montes Alpes – Alps Mountains
Montes Apenninus – Apennines Mountains
Oceanus Procellarum – Ocean of Storms
Sinus Asperitatis – Golfe des Asperites
Sinus Iridium – Bay of Rainbows
Sinus Medii – Central Bay
04/26/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Ephemeris for Wednesday, April 26th. Today the Sun will be up for 14 hours even, setting at 8:41, and it will rise tomorrow at 6:39. The Moon, 1 day before first quarter, will set at 3:28 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. It’s in Gemini, below the namesake stars of the twins Castor on the right and Pollux on the left. Pollux is a bit below and to the right of the Moon tonight. Mars is above and left of Venus. 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. They won’t cross paths until February of next year. Saturn is emerging from morning twilight, rising at 4:33 am in the east-southeast. Both Jupiter and Mercury are too close to the direction of the Sun to be seen.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –4 hours). They may be different for your location.
Addendum

Evening planets and stars looking westward at 10 pm tonight, April 26, 2023. Click or tap on the image to enlarge it. Created using Stellarium and GIMP.

The Moon, one day before first quarter tonight, April 26, 2023, with prominent features labeled. Created using Stellarium, GIMP and LibreOffice Draw.

Telescopic Venus and Saturn (north up) as they would be seen in a small telescope, with the same magnification. Apparent diameters: Venus 16.51″ and is 68.1% illuminated; Saturn 16.23″, its rings 37.80″. Mars is too small to be represented here. It is 5.5″ in diameter. Created using Cartes du Ciel (Sky Charts).
04/19/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Ephemeris for Wednesday, April 19th. Today the Sun will be up for 13 hours and 40 minutes, setting at 8:32, and it will rise tomorrow at 6:50. The Moon, 1 day before new, will rise at 7:04 tomorrow morning.
Let’s find where the naked-eye planets have wandered off to this week. Since I left you in February, Jupiter passed behind the Sun 8 days ago and moved to the morning side of the Sun. Though it will be more than a month before it is far enough from the Sun to be spotted before sunrise. Venus is our blazing Evening Star, seen in the west all evening. It will set shortly after midnight. It’s in Taurus, with the bright star Aldebaran below and left of it and the Pleiades below and right of it. Mars is above and left of Venus. Venus is closing the gap, 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, but won’t cross paths until February of next year. In the morning sky, Saturn is now visible by 6 am in the east-southeast.
Addendum

Evening planets Venus and Mars among the bright stars of winter at 9:30 pm with Mercury about to set, April 19, 2023. Created using Stellarium.
02/08/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Bob Moler with Ephemeris for Wednesday, February 8th. Today the Sun will be up for 10 hours and 7 minutes, setting at 6:01, and it will rise tomorrow at 7:52. The Moon, 3 days past full, will rise at 9:02 this evening.
Let’s find where the naked-eye planets have wandered off to this week. Very early after sunset, Venus can be spotted low in the southwest by 6:30 pm. Mars, and Jupiter will be visible this evening by 7 pm. Mars will be above Orion in the southeast and is pulling away from the Pleiades. Jupiter will be in the southwest. Saturn is way below Venus now, so it’s gone until it reappears in the morning sky in a few months. It will make the crossing to the morning sky with its solar conjunction on the 16th. Jupiter will cross paths with Venus on March 1st. Mercury is now in the morning sky, but too close to the Sun to be visible.
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.