Archive
06/23/2023 – Ephemeris – Sun and Star Party scheduled for tomorrow at the Sleeping Bear Dunes
This is Ephemeris for Friday, June 23rd. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:32, and it will rise tomorrow at 5:57. The Moon, 3 days before first quarter, will set at 1:11 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 6 pm to 8 pm. The society has two hydrogen alpha solar telescopes to view the Sun’s chromosphere and prominences. Plus some members also have solar scopes also white light filtered telescopes to view sunspots on the face of the Sun. Night viewing will start at 10 pm with the Moon and Venus featured, along with the brighter telescopic wonders of early summer. The park rangers will leave at midnight, but society members can stay later to view the fainter wonders in the darkened sky. All this will happen only if clouds permit.
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 Dune Climb is not the place to view the spectacular sunset. The best place is from the Lake Michigan Overlook stop on Pierce Stocking Scenic Drive.
06/21/2023 – Ephemeris – Let’s find out where the naked-eye planets have wandered off to this week
This is Ephemeris for Wednesday, June 21st. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:32, and it will rise tomorrow at 5:57. The Moon, 3 days past new, will set at 12:27 tomorrow morning.
Let’s find out where the naked-eye planets have wandered off to this week. Looking below the horizon we see our planet, which will reach the June solstice and the beginning of summer in the northern hemisphere later this morning (10:58 am EDT, 14:58 UT). Venus is our blazing Evening Star seen in the west all evening. It will still set after midnight, but barely. Tonight it is seen below the Moon. The red planet Mars is seen left of and a bit higher than Venus by four and a half degrees, or a bit less than half 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. Both Mars and Venus are in Cancer. In the morning, Saturn will be visible low in the south-southeast at 5 am. Jupiter will be low in the east 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



06/14/2023 – Ephemeris – Let’s find out where the naked-eye planets have wandered off to this week
This is Bob Moler with Ephemeris for Flag Day, Wednesday, June 14th. Today the Sun will be up for 15 hours and 33 minutes, setting at 9:29, and it will rise tomorrow at 5:56. The Moon, half way from last quarter to new, will rise at 3:59 tomorrow morning.
Let’s find out 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 seen left of and a bit higher than Venus by six and a half degrees, or a bit more than half 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 seven moon diameters apart, before Venus pulls back toward the Sun faster than Mars will. Both Mars and Venus are in Cancer. In the morning, Saturn will be visible low in the south-southeast at 5 am. Jupiter will be very low in the east 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




06/07/2023 – Ephemeris – Let’s find where the naked-eye planets have wandered off to this week
This is Bob Moler with Ephemeris for Wednesday, June 7th. Today the Sun will be up for 15 hours and 27 minutes, setting at 9:25, and it will rise tomorrow at 5:57. The Moon, 3 days before last quarter, will rise at 1:18 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 seen left of and a bit higher than Venus by eight and a half degrees, or a bit less 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. Both Mars and Venus are in Cancer. In the morning, Saturn will be visible low in the southeast at 5 am, rising at 1:53 am. Jupiter is low in the east at that hour, rising at 3:57 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




05/31/2023 – 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).
05/19/2023 – Ephemeris – It’s new moon, why is there no solar eclipse today?
This is Bob Moler with Ephemeris for Friday, May 19th. Today the Sun will be up for 14 hours and 58 minutes, setting at 9:08, and it will rise tomorrow at 6:09. The Moon is new today, and won’t be visible.
We are five months from witnessing a solar eclipse. That’s five lunar months, of approximately 29 and a half days. Solar eclipses can only happen at new moon, when the Moon is in the same direction as the Sun. Today, at 11:53 am, the instant of new moon, the Moon will be about two and a half of its diameters north of the Sun, so it won’t create a solar eclipse for us in Northern Michigan, or for any other place on the Earth for that matter. For locations south of Michigan, that Moon will appear somewhat farther from the Sun. For locations north of us, the Moon will appear closer to the Sun. But nobody will get a solar eclipse today. We will have to wait for the new moon of October 14th to see an eclipse of 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.
Addendum
The orbit of the Moon is tilted by about 5 degrees from the orbital plane of the Earth, so there’s a solar eclipse visible somewhere on the planet one out of six new moons on average. If our moon orbited near the earth’s equator like most major moons of their planet, eclipses would be much rarer than they are now, and only occur around the spring or autumn equinoxes. That’s because the Moon’s orbit would be tilted, on average, of 23½ degrees to Earth’s orbital plane.

The new moon’s position north of the Sun at 11:53 am EDT. The yellow line is the ecliptic, which is the path of the Sun against the stars, or Earth’s orbital plane projected on the sky. If one could see the stars in the daytime, the Sun and Moon are below the Pleiades star cluster, which will make their first appearance in the evening sky this fall. While 11:53 am is only 7 minutes from noon EDT, for our location, local apparent solar noon, when the Sun is actually due south, isn’t until 1:39 pm. Our Eastern Daylight Saving Time meridian is off the coast of the US in the Atlantic Ocean at longitude 60 degrees west. We are located between 85 and 86 degrees west. 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).










