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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.
09/09/2021 – Ephemeris – The constellation of Cassiopeia the Queen
This is Ephemeris for Thursday, September 9th. Today the Sun will be up for 12 hours and 49 minutes, setting at 8:04, and it will rise tomorrow at 7:16. The Moon, 3 days past new, will set at 9:40 this evening.
Tonight, check out the crescent Moon, with Venus below left of it. Cassiopeia is a constellation shaped like the letter W seen in the northeast these evenings. In Greek mythology, she was the queen of Ethiopia. She was very beautiful and very boastful of that fact. She even compared her beauty with that of the sea nymphs, daughters of the sea god Poseidon. Papa was not amused. So Cassiopeia’s daughter, the Princess Andromeda, was made to suffer for it. Poseidon sent a sea monster, Cetus, to ravage the coastal cities of the country. The only way to stop it was to sacrifice Andromeda to the monster. Andromeda and Cetus are constellations we’ll meet in the coming weeks. We’ve already met Pegasus, the flying horse, rising in the east. And we are yet to meet the hero, Perseus.
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 and the Moon in evening twilight, about a half hour after sunset tonight, September 9, 2021. Created using Stellarium.
Cassiopeia finder animation looking northeast in mid-September, an hour and a half after sunset. Created using Stellarium.
09/08/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Ephemeris for Wednesday, September 8th. Today the Sun will be up for 12 hours and 52 minutes, setting at 8:06, and it will rise tomorrow at 7:14. The Moon, 2 days past new, will set at 9:16 this evening.
Let’s search for the naked-eye planets for this week. Venus should be visible in the western evening twilight before 8:30 tonight. It will set at 9:41 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 visible for most of the night, with Saturn setting first at 3:53 am, with Jupiter setting at 5:21 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 and the Moon in evening twilight at 8:30 pm tonight, September 8, 2021. This is about 25 minutes after sunset. Created using Stellarium.
The thin crescent Moon as it might appear with earth shine in binoculars at 8:30 pm tonight, September 8, 2021. Created using Stellarium.
Jupiter and Saturn in the southeast at 8:30 pm, about a half hour after sunset tonight, September 8, 2021. 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, and the other two at 10 pm, September 8, 2021. Apparent diameters: Venus, 15.88″ 70% illuminated; Saturn 18.19″, its rings 42.36″; Jupiter, 48.43″. Jupiter’s moons will slowly approach the planet from our viewpoint overnight. 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 8, 2021. The night ends on the left with sunrise on the 9th. Click on the image to enlarge it. Created using my LookingUp program.
09/01/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Ephemeris for Wednesday, September 1st. Today the Sun will be up for 13 hours and 13 minutes, setting at 8:18, and it will rise tomorrow at 7:06. The Moon, 2 days past last quarter, will rise at 1:57 tomorrow morning.
Let’s search for the naked-eye planets for this week. Venus should be visible in the western evening twilight before 9 tonight. It will set at 9:41 pm. By 9 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 visible for most of the night, with Saturn setting first at 4:22 am, with Jupiter setting at 5:53 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 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 twilight at 8:45 pm, about 1/2 hour after sunset tonight, September 1, 2021. Created with Stellarium.
Jupiter and Saturn in the southeast about three quarters of an hour after sunset. Created using Stellarium.
The waning crescent Moon as it might be seen in binoculars or low magnification telescope at 6 am tomorrow morning, September 2, 2021.
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 9 pm, and the other two at 11 pm, September 1, 2021. Apparent diameters: Venus, 15.16″, 73% illuminated; Saturn 18.32″, its rings 42.67″; Jupiter, 48.83″. Jupiter’s moons Io and Europa will slowly approach the planet over the morning hours. Io will be occulted by the planet around 4:05 am (08:05 UT). Europa will begin its transit across the face of the planet around 5:04 am (09:04 UT). 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). Jovian satellite event times determined from Stellarium.
Planets and the Moon at sunset and sunrise of a single night, starting with sunset on the right on September 1, 2021. The night ends on the left with sunrise on the 2nd. Click on the image to enlarge. Created using my LookingUp program.
Note: Mars and Mercury are too close to the direction of the Sun to be visible from Northern Michigan. However, Mercury will be easily visible far south of here and into the Southern Hemisphere.
08/25/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Ephemeris for Wednesday, August 25th. Today the Sun will be up for 13 hours and 34 minutes, setting at 8:31, and it will rise tomorrow at 6:58. The Moon, 3 days past full, will rise at 10:20 this evening.
Let’s search for the naked-eye planets for this week. Venus should be visible in the western evening twilight before 9 tonight. It will set at 9:53 pm. By 9 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 visible for most of the night, with Saturn setting first at 4:52 am, with Jupiter setting at 6:26 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 moon can 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 tonight, August 25, 2021 at 9 pm, about 1/2 hour after sunset. Created using Stellarium.
Jupiter and Saturn in the southeast at 9:30 pm tonight, August 25, 2021, about 45 minutes after sunset. Created using Stellarium.
The Moon as it might appear tonight in binoculars or a small telescope at 11:30 pm, about an hour after it rises tonight, August 25, 2021. 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 9:15 pm, and the other two at 11 pm, August 25, 2021. Apparent diameters: Venus, 14.51″ 75% illuminated; Saturn 18.43″, its rings 42.93″; Jupiter, 49.06″. Jupiter’s moons Io and Ganymede will slowly separate after 11 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).
Planets and the Moon at sunset and sunrise of a single night, starting with sunset on the right on August 25, 2021. The night ends on the left with sunrise on the 26th. Click on the image to enlarge. Created using my LookingUp program.
08/18/2021 – Ephemeris – Let’s search for the naked-eye planets for this week
This is Bob Moler with Ephemeris for Wednesday, August 18th. Today the Sun will be up for 13 hours and 54 minutes, setting at 8:43, and it will rise tomorrow at 6:50. The Moon, 3 days past first quarter, will set at 3:02 tomorrow morning.
Let’s search for the naked-eye planets for this week. Venus should be visible in the western evening twilight by 9:15 tonight. It will set at 10:04 pm. By 9:30 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. Jupiter, just a day from opposition from the Sun, will be at its brightest and closest to us. It’s now 373 million miles (600 million km) from us. It won’t change much by tomorrow. Actually it’s a closer approach than average, so it’s brighter than at an average opposition and larger appearing than normal in telescopes. Jupiter and four of its largest moons always provide for a great show.
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 low in the west, tonight at 9:15, about a half hour after sunset, August 18, 2021. Created using Stellarium.
Jupiter, Saturn and the Moon at 10 pm, about an hour and a quarter after sunset tonight, August 18, 2021. Click on the image to enlarge it. Created using Stellarium.
The waxing gibbous Moon as it might appear tonight in binoculars or a small telescope. 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 10 pm, and the other two at 11 pm, August 18, 2021. Apparent diameters: Venus, 13.93″; Saturn 18.51″, its rings 43.13″; Jupiter, 49.12″. Jupiter’s moon have a cluster of events in the am hours. See below. 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).
Satellite Event EDT (UT-4) UT Europa Shadow start 12:34 am 04:34 Europa Transit start 12:37 am 04:37 Io Occultation start 12:37 am 04:37 Ganymede Eclipse start 12:43 am 04:43 Io Occultation end 2:55 am 06:55 Europa Shadow end 3:25 am 07:25 Europa Transit end 3:27 am 07:27 Ganymede Occultation end 4:24 am 08:24 From 12:43 to 2:55 am, only Callisto of the four Galilean moons will be visible.
The above times were determined using Stellarium, and may be off by several minutes.
Shadow events are when a satellite’s shadow is cast onto the face of the planet
Transit events are when the satellite passes in front of the planet. The satellite is usually not visible
Eclipse events are when a satellite passes through the planet’s shadow
Occultation events are when the satellite passes behind the planet
The naked-eye planets and the Moon are shown at sunset and sunrise of a single night, starting with sunset on the right on August 18, 2021. The night ends on the left with sunrise on the 19th. Mars and Mercury will be in conjunction in Leo that evening, so their labels overlap. Click on the image to enlarge. Created using my LookingUp program.
08/11/2021 – Ephemeris – Let’s search for the naked-eye planets for this week, and meteors tonight
This is Bob Moler with Ephemeris for Wednesday, August 11th. Today the Sun will be up for 14 hours and 13 minutes, setting at 8:54, and it will rise tomorrow at 6:42. The Moon will be 3 days past new tonight.
Let’s search for the naked-eye planets for this week. Venus and the Moon will be close together tonight, with Venus below and right of the waxing crescent Moon by 9:30 tonight. Venus will set at 10:18 pm. With the Moon following at 10:50. By 10 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. Tonight and especially in the morning hours tomorrow, the Perseid meteors will be at their peak. These bits of Comet Swift-Tuttle, liberated by the comet’s prior passes in through the warmth of the inner solar system, will flash into incandescence as they enter the Earth’s atmosphere at interplanetary speeds.
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 and the 3-day-old Moon ion evening twilight at 9:45 tonight, August 11, 2021. Created using Stellarium.
The Moon as it might appear in binoculars tonight, August 11, 2021, with earth shine on its night side, illuminated by the bright Earth in its sky.
Created using Stellarium.
Jupiter and Saturn in the southeastern sky at 10:30 in the evening tonight, August 11, 2021. 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, at 10 pm August 11, 2021. Apparent diameters: Venus, 13.40″; Saturn 18.57″, its rings 43.26″; Jupiter, 49.00″. Jupiter’s moon have a cluster of events in the evening. See below. 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).
Jupiter's Satellite events
Moon Event EDT (pm-11th, am-12th) UT (12th)
Europa Shadow enters 10:00 pm 02:00
Europa Transit starts 10:25 pm 02:25
Io Eclipse starts 10:41 pm 02:41
Europa Shadow exits 12:51 am 04:51
Ganymede Occultation ends 1:06 am 05:06
Io Occultation ends 1:11 am 05:11
Europa Transit ends 1:12 am 05:12
The above times were determined using Stellarium, and may be off by several minutes.
Shadow events are when a satellite’s shadow is cast onto the face of the planet
Transit events are when the satellite passes in front of the planet
Eclipse events are when a satellite passes through the planet’s shadow
Occultation events are when the satellite passes behind the planet
Planets and the Moon at sunset and sunrise of a single night, starting with sunset on the right on August 11, 2021. The night ends on the left with sunrise on the 12th. Click on the image to enlarge. Created using my LookingUp program.
Perseid Radiant finder automation for midnight, August 11th. Created using Stellarium and GIMP.
More on the Perseids on Monday and Tuesday’s posts.
Bob Moler's Ephemeris Blog 