Archive
11/08/2021 – Ephemeris – The next two months will be prime time to view Venus in a telescope
This is Bob Moler with Ephemeris for Monday, November 8th. Today the Sun will be up for 9 hours and 51 minutes, setting at 5:21, and it will rise tomorrow at 7:32. The Moon, 3 days before first quarter, will set at 8:37 this evening.
Venus is beginning to look like the crescent Moon in telescopes. Right now it’s a very fat crescent. The reason is that since its greatest separation from the Sun a bit more than a week ago, Venus’ sunlit side is more and more turned away from us as it starts to move between the Earth and Sun. Venus is also rapidly approaching us now and is 54.9 million miles (88.3 million kilometers) away. A month from now it will appear larger than Jupiter, so Venus’ thinning crescent might be glimpsed in binoculars. Venus’ size will grow and crescent will get even thinner until it passes between the Earth and Sun, which will occur January 8th next year. That’s called inferior conjunction with the Sun. From our vantage point, it will pass just north of the Sun, and a week or so later will be seen in the morning sky.
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.
Addendum
Animated GIF of Venus’ last 2 months in the evening sky, November 8, 2021, to January 8, 2022. After mid-December the crescent is too thin to show in the program, but can actually be seen. I’ve spotted Venus as close as 4 days before inferior conjunction. Created using Stellarium and Filmora.
11/03/2021 – Ephemeris – Searching for the naked-eye planets for this week
This is Ephemeris for Wednesday, November 3rd. The Sun will rise at 8:23. It’ll be up for 10 hours and 4 minutes, setting at 6:28. The Moon, 1 day before new, will rise at 7:56 tomorrow morning.
Let’s search for the naked-eye planets for this week. Venus should be visible in the southwestern evening twilight by 6:50 tonight. It’s a fat crescent in telescopes. Venus will set at 8:44 pm. By 7 pm, Jupiter should be able to be spotted in the south-southeastern sky. Saturn will be dimmer, and to its right. They will set after midnight in the southwest, with Saturn setting first at 12:11 am, and Jupiter following at 1:32. Saturn’s rings are a beautiful sight in a telescope of even modest power, but the planet will appear tiny. In the morning sky, Mercury will be harder to spot than it was last week. It will be visible and low in the east-southeast from 7:30 to 8 am. All four of Jupiter’s brightest moons will be visible in binoculars early in the evening tonight.
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 will appear low in the south-southwest by 6:50 pm tonight, November 3, 2021. Created using Stellarium.
Venus, Jupiter and Saturn at 7 pm in the southern sky. Created using Stellarium.
Mercury in morning twilight at 7:45 am, November 4, 2021. Created using Stellarium.
Telescopic views of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening at 9 pm, November 3, 2021. Apparent diameters: Venus at 7 pm, 26.54″, 46.7% illuminated; Saturn 16.69″, its rings 38.88″; Jupiter, 41.77″. Mercury at 7:30 am on the 4th and not plotted, 5.49″, 86.4% illuminated. The Jovian moon Io will begin transiting the face of the planet at 11:14 pm. Its shadow will start to cross at 12:32 am. 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 November 3, 2021. The night ends on the left with sunrise on the 4th. Click on the image to enlarge it. Created using my LookingUp program.
10/27/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Wednesday, October 27th. Today the Sun will be up for 10 hours and 23 minutes, setting at 6:38, and it will rise tomorrow at 8:15. The Moon, 1 day before last quarter, will rise at 11:27 this evening.
Let’s search for the naked-eye planets for this week. Venus should be visible in the southwestern evening twilight by 7 tonight. It will set at 8:43 pm. By 7:15 pm, Jupiter will be spotted in the south-southeastern sky. Jupiter should be easy to spot at that hour. Saturn will be dimmer, and to its right. They will be visible for a while after midnight in the southwest, with Saturn setting first at 12:37 am, and Jupiter following at 1:57. Saturn’s rings are a beautiful sight in a telescope of even modest power, but the planet will appear tiny. In the morning sky, Mercury will be visible and low in the east-southeast for most of the 7 am hour. All four of Jupiter’s brightest moons will be visible in binoculars early in the evening tonight.
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 will appear low in the southwest by 7 pm tonight, October 27, 2021. Created using Stellarium.
Jupiter and Saturn in evening twilight at 7:15 pm tonight, October 27, 2021. Created using Stellarium.
The Moon as it might appear in binoculars or a small telescope tomorrow morning, October 28, 2021. Created using Stellarium.
Mercury in morning twilight finder for 7:30 am tomorrow, October 28, 2021. Created using Stellarium.
Telescopic views of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening at 9 pm, October 27, 2021. Apparent diameters: Venus at 7 pm, 24.19″, 50.8% illuminated; Saturn 16.92″, its rings 39.41″; Jupiter, 42.87″. Mercury at 7:30 am on the 28th and not plotted, 6.47″, 64.9% illuminated. The Jovian moon Io will begin transiting the face of the planet at 9:20 pm. Its shadow will start to cross at 10:37 pm. Io’s transit will end at 11:37 pm. 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 October 27, 2021. The night ends on the left with sunrise on the 28th. Click on the image to enlarge it. Created using my LookingUp program.
10/20/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Wednesday, October 20th. Today the Sun will be up for 10 hours and 44 minutes, setting at 6:49, and it will rise tomorrow at 8:06. The Moon, is full today, the Hunter’s Moon, and will rise at 7:07 this evening.
Let’s search for the naked-eye planets for this week. Venus should be visible in the southwestern evening twilight by 7:10 tonight. It will set at 8:44 pm. By 7:30 pm, Jupiter will be spotted in the south-southeastern sky. Jupiter should be easy to spot at that hour. Saturn will be dimmer, and to its right. They will be visible for a while after midnight in the southwest, with Saturn setting first at 1:04 am, and Jupiter following at 2:24. Saturn’s rings are a beautiful sight in a telescope of even modest power, but the planet will appear tiny. In the morning sky, Mercury will be visible and low in the east-southeast by 7:15 am. It will reach its greatest separation from the Sun in six days.
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 seen in twilight at 7:10 pm, about 20 minutes after sunset tonight, October 20, 2021. Created using Stellarium.
Full Hunter’s Moon rising at 7:11 this evening, October 20, 2021. Created using Stellarium.
Jupiter, Saturn and the Moon at 7:30, about 40 minutes after sunset tonight, October 20, 2021. Created using Stellarium.
Mercury and the star Arcturus in the morning twilight at 7:15 am, about 50 minutes before sunrise tomorrow morning, October 21, 2021. Don’t confuse the two. Click on the image to enlarge it. Created using Stellarium.
Telescopic views of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening at 8 pm, October 20, 2021. Apparent diameters: Venus, 22.70″, 53.7% illuminated; Saturn 17.08″, its rings 39.80″; Jupiter, 43.68″. Mercury at 7:15 am on the 21st and not plotted, 7.68″, 38.1% illuminated. The two Jovian moons transiting the face of the planet are usually not visible, though their shadows can be spotted. 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 October 20, 2021. The night ends on the left with sunrise on the 21st. Click on the image to enlarge it. Created using my LookingUp program.
10/18/2021 – Ephemeris – Jupiter is stationary today
This is Ephemeris for Monday, October 18th. Today the Sun will be up for 10 hours and 50 minutes, setting at 6:52, and it will rise tomorrow at 8:03. The Moon, 2 days before full, will set at 6:49 tomorrow morning.
The planet Jupiter is stationary today after moving westward for the last four months, as the Earth passed it in our race around the Sun. And it will resume its normal prograde or eastward motion against the stars and constellations of the Zodiac. During this retrograde time it had seemed to move closer to Saturn. Now that it and Saturn are appearing to resume their eastward motion, Jupiter again will appear to open up the distance between them. The ancient Greeks had a devil of a time trying to model this behavior, because they started with two false premises. One, that the Earth was stationary in the center of the universe; and two, that the Sun, Moon, and planets moved in uniform circular motion because they were perfect.
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
Jupiter and Saturn’s apparent motions seen against the constellation of Capricornus in 2021, including their retrograde loops. Click on the image to enlarge it. The tracks begin on the right. By the end of 2021 neither planet recovers all the eastern progress they lost in their retrograde loops. Created using Cartes du Ciel (Sky Charts).
10/13/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Ephemeris for Wednesday, October 13th. Today the Sun will be up for 11 hours and 5 minutes, setting at 7:01, and it will rise tomorrow at 7:57. The Moon, 1 day past first quarter, will set at 1:00 tomorrow morning.
Let’s search for the naked-eye planets for this week. Venus should be visible in the southwestern evening twilight by 7:20 tonight. It will set at 8:37 pm. By 7:45 pm, Jupiter will be spotted in the south-southeastern sky. The Jupiter should be easy to spot at that hour. Saturn will be dimmer, and to its right. It will be above and left of the Moon tonight. They will be visible for a while after midnight in the southwest, with Saturn setting first at 1:31 am, and Jupiter following at 2:52. Saturn’s rings are a beautiful sight in a telescope of even modest power, but the planet will appear tiny. Jupiter’s 4 brightest moons are spread out, two on each side of the planet tonight. They might all be visible in binoculars.
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 seen in twilight at 7:20 pm, about 20 minutes after sunset on October 13, 2021. Created using Stellarium.
Jupiter, Saturn and the Moon at 7:45, about 45 minutes after sunset in this view to the south-southeast. Click on the image to enlarge it. Created using Stellarium.
The slight gibbous Moon as it might appear tonight in binoculars or small telescope. It appears here right side up as it would appear in the sky at 9 pm. Created using Stellarium.
Telescopic views of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening at 9 pm, October 13, 2021. Apparent diameters: Venus, 21.15″, 56.8% illuminated; Saturn 17.29″, its rings 40.27″; Jupiter, 44.63″. 9 pm is also the best time to find the Great Red Spot on Jupiter’s face. Io will be in transit of the face of Jupiter until 7:53 pm. After that, Io will be increasing its distance from the planet. 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 October 13, 2021. The night ends on the left with sunrise on the 14th. It looks like Mercury will be far enough from the Sun next week to spot in the morning. Click on the image to enlarge it. Created using my LookingUp program.
10/06/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Ephemeris for Wednesday, October 6th. Today the Sun will be up for 11 hours and 26 minutes, setting at 7:13, and it will rise tomorrow at 7:48. The Moon is new today, and won’t be visible.
Let’s search for the naked-eye planets for this week. Venus should be visible in the southwestern evening twilight by 7:45 tonight. It will set at 8:52 pm. By 8 pm, Jupiter will be spotted in the south-southeastern sky. The Jupiter should be easy to spot at that hour. Saturn will be dimmer, but a bit higher and to its right. They will be visible into the morning hours, with Saturn setting first at 1:58 am, and Jupiter following at 3:20. Saturn’s rings can be seen in a spotting scope of about 20 power magnification. Though at that power the rings won’t appear separated from the planet, so Saturn will look like an elliptical disk. Jupiter’s 4 brightest moons are spread out, three on one side, and one on the other. They might all be visible in binoculars tonight.
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 in evening twilight at 7:45 pm, about a half hour after sunset. Created using Stellarium.
Jupiter and Saturn at 8 pm, about 45 minutes after sunset tonight, October 6, 2021. Created using Stellarium.
Telescopic views of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening at 8 pm, October 6, 2021. Apparent diameters: Venus, 19.81″, 59.8% illuminated; Saturn 17.48″, its rings 40.73″; Jupiter, 45.55″. 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 October 6, 2021. The night ends on the left with sunrise on the 7th. Click on the image to enlarge it. Created using my LookingUp program.
09/29/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Ephemeris for Wednesday, September 29th. Today the Sun will be up for 11 hours and 47 minutes, setting at 7:26, and it will rise tomorrow at 7:39. The Moon, 1 day past last quarter, will rise at 12:40 tomorrow morning.
Let’s search for the naked-eye planets for this week. Venus should be visible in the southwestern evening twilight by 7:45 tonight. It will set at 8:59 pm. By 8 pm, Jupiter will be spotted in the southeastern sky. The Jupiter should be easy to spot at that hour. Saturn will be dimmer, but a bit higher and to its right. They will be visible into the morning hours, with Saturn setting first at 2:26 am, with Jupiter following at 3:49. Saturn’s rings can be seen in a spotting scope of about 20 power magnification. Though at that power the rings won’t appear separated from the planet, so Saturn will look like an elliptical disk. Jupiter’s four brightest moons are spread out, two on each side. They all might be visible in binoculars tonight.
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 in evening twilight at 7:45 pm, about a half hour after sunset tonight, September 29, 2021. Created using Stellarium.
Jupiter and Saturn in the southeast at 8 pm. Created using Stellarium.
Low magnification view of the waxing crescent Moon as it would appear at 6:30 am tomorrow, September 30, 2021. Created using Stellarium.
Telescopic views of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening at 8 pm, September 29, 2021. Apparent diameters: Venus, 18.65″, 62.6% illuminated; Saturn 17.68″, its rings 41.18″; Jupiter, 46.41″. 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 September 29, 2021. The night ends on the left with sunrise on the 30th. Click on the image to enlarge it. Created using my LookingUp program.
09/22/2021 – Ephemeris – Autumn starts this afternoon and a look at the naked-eye planets
This is Bob Moler with Ephemeris for Wednesday, September 22nd. Today the Sun will be up for 12 hours and 9 minutes, setting at 7:39, and it will rise tomorrow at 7:31. The Moon, 2 days past full, will rise at 8:43 this evening.
Here on Earth, the season of fall will begin at 3:21 this afternoon. Let’s search for rest of the naked-eye planets for this week. Venus should be visible in the southwestern evening twilight by 8 o’clock tonight. It will set at 9:08 pm. By 8:15 pm, Jupiter and Saturn will be seen low in the southeastern sky. The brighter Jupiter will be easy to spot at that hour. Saturn will be dimmer, but a bit higher and to its right. They will be visible into the morning hours, with Saturn setting first at 2:55 am, with Jupiter following at 4:19. Saturn’s rings can be seen in a spotting scope of about 20 power magnification. Though at that power the rings won’t appear separated from the planet, so Saturn will look like an elliptical disk.
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 in twilight at 8 pm, or about 20 minutes after sunset, tonight, September 22, 2021. An animation showing its altitude at that time of 10 degrees (about the width of your fist held at arm’s length). Created using Stellarium and GIMP.
Waning gibbous Moon, about 15 minutes after rising as it might be visible in binoculars or small telescope. Created using Stellarium.
Telescopic views of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening. Venus at 8 pm, Jupiter and Saturn at 10 pm, September 22, 2021. Apparent diameters: Venus, 17.61″, and 65.3% illuminated; Saturn 17.86″, its rings 41.61″; Jupiter, 47.20″. 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 at sunset and sunrise of a single night, starting with sunset on the right on September 22, 2021. The night ends on the left with sunrise on the 23rd. Click on the image to enlarge it. Created using my LookingUp program.
09/15/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Ephemeris for Wednesday, September 15th. Today the Sun will be up for 12 hours and 30 minutes, setting at 7:52, and it will rise tomorrow at 7:23. The Moon, 2 days past first quarter, will set at 1:59 tomorrow morning.
Let’s search for the naked-eye planets for this week. Venus should be visible in the western evening twilight before 8:15 tonight. It will set at 9:19 pm. By 8:30 pm, Jupiter and Saturn will be seen low in the southeastern sky. The brighter Jupiter will be easy to spot at that hour. Saturn will be dimmer, but a bit higher and to its right. Both these planets will be to the left of the bright gibbous Moon. They will be visible for most of the night, with Saturn setting first at 3:24 am, with Jupiter setting at 4:50 tomorrow morning. Saturn’s rings can be seen in a spotting scope of about 20 power magnification. Though at that power, the rings won’t appear separated from the planet, so Saturn will look like an elliptical spot. Most of Jupiter’s 4 brightest moons can even be spotted in binoculars.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.
Addendum
Venus in evening twilight at 8:15 tonight, about 20 minutes after sunset, September 15, 2021. Created using Stellarium.
Jupiter Saturn and the Moon at 8:30 tonight, about 40 minutes after sunset, September 15, 2021. Created using Stellarium.
Low magnification view of the Moon tonight. The large crater Clavius is seen at the south (bottom) of the Moon. The crater Copernicus is seen near the left edge of the Moon, the sunrise terminator. Created using Stellarium.
Telescopic view of the bright planets (north up) as they would be seen in a small telescope, with the same magnification, this evening. Venus at 8:30 pm, September 15, 2021. Apparent diameters: Venus, 16.70″ 68% illuminated; Saturn 18.03″, its rings 42.00″; Jupiter, 47.88″. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).
Planets and the Moon at sunset and sunrise of a single night, starting with sunset on the right on September 15, 2021. The night ends on the left with sunrise on the 16th. Click on the image to enlarge. Created using my LookingUp program.
Bob Moler's Ephemeris Blog 