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09/22/2022 – Ephemeris – Autumn will begin this evening
This is Ephemeris for Thursday, September 22nd. Today the Sun will be up for 12 hours and 10 minutes, setting at 7:40, and it will rise tomorrow at 7:31. The Moon, 3 days before new, will rise at 4:46 tomorrow morning.
The season of fall is about to, ah well, fall upon us and in a few weeks so will the leaves. At 9:04 this evening (1:04 UT tomorrow) the Sun will cross the celestial equator heading south. The celestial equator is an imaginary line in the sky above the earth’s equator. At that point, the Sun will theoretically set at the North Pole and rise at the South Pole. The day is called the autumnal equinox and the daylight hours today is 12 hours and 10 minutes instead of 12 hours exactly. That’s due to our atmosphere and our definition of sunrise and sunset. The reason for the cooler weather now and the cold weather this winter is that the length of daylight is shortening, and the Sun rides lower in the sky, spreading its heat over a larger area, thus diluting its intensity.
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 Sun’s path through the sky on an equinox day from the Traverse City/Interlochen area in Michigan. The Sun is plotted every 15 minutes. This is a stereographic projection which compresses the image near the zenith and enlarges the image towards the horizon. Note that the Sun rises due east and sets due west. Created using my LookingUp program.
That is not a pumpkin on the head of the motorcyclist. That’s the Sun rising as I’m traveling east on South Airport Road south of Traverse City, MI on the autumnal equinox. This is the east-west section of the road. The Sun is rising over the hills some 6 miles to the east. When the Sun is on the celestial equator, it rises due east and sets due west. Credit: Bob Moler.
Image from the Earth Polychromatic Imaging Camera (EPIC) on NOAA’s DSCOVR satellite in halo orbit around the Earth-Sun L-1 point 1 million miles sunward from the Earth on the autumnal equinox of 2016. North America is in the upper right of the globe.
Earth’s position at the solstices and equinoxes. This is an not to scale oblique look at the Earth’s orbit, which is nearly circular. The Earth is actually farthest from the Sun on July 4th. Click on the image to enlarge. Credit: ESO (European Southern Observatory), which explains the captions in German and English.
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.
09/21/2021 – Ephemeris – Autumn starts tomorrow
This is Bob Moler with Ephemeris for Tuesday, September 21st. Today the Sun will be up for 12 hours and 12 minutes, setting at 7:41, and it will rise tomorrow at 7:30. The Moon, 1 day past full, will rise at 8:23 this evening.
Enjoy the last full day of summer. Summer will last until 3:21 pm (19:21 UTC) tomorrow, when the center of the Sun will cross the celestial equator, an imaginary line above the Earth’s equator, heading southward. At that instant, autumn will begin. Shortly after, the Sun will be up less than half the day. The day and the point in the sky that the Sun crosses is called the autumnal equinox. The word equinox means equal night, implying that day and light are of equal length. Geometrically that’s true, but the Earth’s atmosphere and the definition of sunrise and sunset, prolong daylight by a few minutes. The amount of heat we are getting and will get from the Sun cannot sustain our current temperatures, and it will get a lot colder on average before it gets warmer again.
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
That is not a pumpkin on the head of the motorcyclist. That’s the Sun rising as I’m traveling east on South Airport Road south of Traverse City, MI on the autumnal equinox. This is the east-west section of the road. The Sun is rising over the hills some 6 miles to the east. When the Sun is on the celestial equator, it rises due east and sets due west. Credit: Bob Moler.
The Sun’s path through the sky on an equinox day from the Traverse City/Interlochen area in Michigan. The Sun is plotted every 15 minutes. This is a stereographic projection which compresses the image near the zenith and enlarges the image towards the horizon. Created using my LookingUp program.
Earth 3 days before autumnal equinox, 1:17 pm EDT, September 19, 2021. The mitten shape of Michigan was in the clear that day and is visible above center of the image. The image taken by the Earth Polychromatic Imaging Camera (EPIC) on the DSCOVR satellite in halo orbit around the Earth-Sun L1 Lagrange point, about a million miles sunward of the Earth. At the time, DSCOVR was 892,682 miles (1,436,797 kilometers) from Earth.
09/22/2020 – Ephemeris – Autumn starts this morning
This is Bob Moler with Ephemeris for Tuesday, September 22nd. Today the Sun will be up for 12 hours and 8 minutes, setting at 7:39, and it will rise tomorrow at 7:31. The Moon, 1 day before first quarter, will set at 11:05 this evening.
Fall is about to a, well… fall upon us and in a few weeks so will the leaves. At 9:31 this morning (13:31 UTC*) the Sun will cross the celestial equator heading south. The celestial equator is an imaginary line in the sky above the earth’s equator. At that point the Sun will theoretically set at the north pole and rise at the south pole. The day is called the autumnal equinox and the daylight hours today is 12 hours and 8 minutes instead of 12 hours exactly. That’s due to our atmosphere and our definition of sunrise and sunset. The reason for the cooler weather now and the cold weather this winter is that the length of daylight is shortening, and the Sun rides lower in the sky, spreading its heat over a larger area, thus diluting its intensity.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
* UTC – Coordinated Universal Time. Greenwich Mean Time if you haven’t kept up. Zulu if you’re in the military.
The Sun crossing the celestial equator in three steps: 9:31 am Sept 21, 22, and 23 2020. Created using Stellarium and GIMP.
The Sun’s path through the sky on the equinox day from Traverse City, MI. Created using my LookingUp program.
That is not a pumpkin on the head of the motorcyclist. That’s the Sun rising as I’m traveling east on South Airport Road south of Traverse City Mi. on the autumnal equinox. This is the east-west section of the road. The Sun is rising over the hills some 6 miles to the east. Credit: Bob Moler.
09/21/2020 – Ephemeris – This is the last full day of summer
This is Ephemeris for Monday, September 21st. Today the Sun will be up for 12 hours and 11 minutes, setting at 7:41, and it will rise tomorrow at 7:30. The Moon, 2 days before first quarter, will set at 10:24 this evening.
Enjoy the last full day of summer. Summer will last until 9:31 am (05:31 UTC) tomorrow when the center of the Sun will cross the celestial equator, an imaginary line above the Earth’s equator, heading southward. At that instant autumn will begin for Earth’s northern hemisphere and spring will begin in the southern hemisphere. Shortly, for us, the Sun will be up less than half the day. The day and the point in the sky that the Sun crosses is called the autumnal or September equinox. The word equinox means equal night, implying the equality of day and night. Geometrically that’s true, but the Earth’s atmosphere and the definition of sunrise and sunset, prolong daylight by a few more minutes. The amount of heat we are getting and will get from the Sun cannot sustain our current temperatures, and it will get a lot colder on average before it gets warmer again.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Sun crossing the celestial equator in the sky moving southward in three steps: 9:31 am Sept 21, 22, and 23 2020. The vertical axis is declination, the exact match to latitude on the Earth. The horizontal line at 00°00′ is the celestial equator, a projection of the Earth’s equator on the sky. The diagonal line that the Sun appears to travel on is the ecliptic, the plane of the Earth’s orbit. Due to the tilt of the Earth’s axis it is inclined by 23.5° to the celestial equator. The horizontal values mark right ascension, the celestial analog of longitude. One hour equals 15°. Since the Earth rotates, the right ascension that is on one’s meridian, the north-south line passing through the zenith, is best kept track of by using a clock. A clock that runs 3 minutes 56 seconds fast a day. We call that a sidereal clock. Created using Cartes du Ciel (Sky Chart) and GIMP.
09/20/2018 – Autumn will fall on us Saturday night
Ephemeris for Thursday, September 20th. The Sun will rise at 7:27. It’ll be up for 12 hours and 16 minutes, setting at 7:43. The Moon, half way from first quarter to full, will set at 3:44 tomorrow morning.
Welcome to the last few days of summer. The weather has stayed summery thus far through September. The Sun will reach the autumnal equinox point in the sky at 9:54 Saturday evening. At that moment the Sun will cross the celestial equator, a projection of the Earth’s equator, heading southward. All locations on the Earth except two will experience 12 hours of daylight and 12 hours of night. Well they would if the Earth didn’t have an atmosphere and sunset and sunrise were defined differently. The two locations that don’t experience equal night, which is what equinox means, are the north pole where the Sun will be setting and the south pole where the Sun will be rising. For us in the northern hemisphere daylight hours will be shorter and the Sun will peak lower in the south each day until the December solstice.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
09/21/2017 – Ephemeris – Summer ends and autumn begins tomottow
Ephemeris for Thursday, September 21st. The Sun will rise at 7:28. It’ll be up for 12 hours and 12 minutes, setting at 7:41. The Moon, 1 day past new, will set at 8:45 this evening.
Enjoy the last full day of summer. Summer will last until 4:02 p.m. (20:02 UTC) tomorrow when the center of the Sun will cross the celestial equator, an imaginary line above the Earth’s equator, heading southward. At that instant autumn will begin. Shortly the Sun will be up less than half the day. The day and the point in the sky that the Sun crosses is called the autumnal equinox. The word equinox means equal night, implying that day and light are of equal length. Geometrically that’s true, but the Earth’s atmosphere and the definition of sunrise and sunset, prolong daylight by a few minutes. The amount of heat we are getting and will get from the Sun cannot sustain our current temperatures, and it will get a lot colder before it gets warmer again.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Image from the Earth Polychromatic Imaging Camera (EPIC) on NOAA’s DSCOVR satellite in halo orbit around the Earth-Sun L-1 point 1 million miles sunward from the Earth last autumnal equinox (2016) at about the same time the autumnal equinox will occur this year.
That is not a pumpkin on the head of the motorcyclist. That’s the Sun rising as I’m traveling east on South Airport Road south of Traverse City Mi. on the autumnal equinox. This is the east-west section of the road. The Sun is rising over the hills some 6 miles to the east. Credit: Bob Moler.
09/22/2016 – Ephemeris – Autumn will begin this morning
Ephemeris for Thursday, September 22nd. The Sun will rise at 7:30. It’ll be up for 12 hours and 8 minutes, setting at 7:39. The Moon, 1 day before last quarter, will rise at 12:06 tomorrow morning.
Fall is about to a, well… fall upon us and in a few weeks so will the leaves. At 10:21 (14:21 UT) this morning the Sun will cross the celestial equator heading south. The celestial equator is an imaginary line in the sky above the earth’s equator. At that point the sun will theoretically set at the north pole and rise at the south pole. The day is called the autumnal equinox and the daylight hours today is 12 hours and 8 minutes instead of 12 hours exactly. That’s due to our atmosphere and our definition of sunrise and sunset. The reason for the cooler weather now and the cold weather this winter is that the length of daylight is shortening, and the Sun rides lower in the sky, spreading its heat over a larger area, thus diluting its intensity.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Earth as seen a couple of days ago from NOAA,s DSCOVR satellite located near the Sun-Earth L-1 point 1 million miles sunward from the Earth. Credit NOAA/NASA.
The Sun’s path through the sky on the equinox day from Traverse City, MI. Created using my LookingUp program.
09/01/2016 – Ephemeris – Previewing the pivotal month of September’s skies
Ephemeris for Thursday, September 1st. The Sun will rise at 7:05. It’ll be up for 13 hours and 12 minutes, setting at 8:18. The Moon is new today, and won’t be visible.
There’s an eclipse of the Sun in progress now for parts of the southern hemisphere centered on southern Africa. Today is also has the first of two new Moons this month, the second being called the Black Moon. Let’s look at the skies for September. The sun is moving at its greatest speed in its retreat to the south. Daylight hours in the Interlochen/Traverse City area and will drop from 13 hours and 12 minutes today to 11 hours 44 minutes on the 30th. The altitude of the sun above the southern horizon at local noon will be 54 degrees today, and will descend to 42 degrees on the 30th. The official season of summer is getting short too, so enjoy it while you can. Summer ends and autumn begins at 10:21 a.m. on September 22nd.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
September Star Chart
Star Chart for September 2016. Created using my LookingUp program. To enlarge in Firefox right-click on image then click View image.
The planets and stars are plotted for the 15th at 10 p.m. EDT. That is chart time. Note, Traverse City is located approximately 45 minutes behind our time meridian. (An hour 45 minutes behind our daylight saving time meridian.) To duplicate the star positions on a planisphere you may have to set it to 1:45 earlier than the current time if you are near your time meridian.
Evening nautical twilight ends at 9:24 p.m. EDT on the 1st, increasing to 8:27 p.m. EDT on the 30th.
Morning nautical twilight starts at 5:59 a.m. EDT on the 1st, and decreasing to 6:37 a.m. EDT on the 30th.
Add a half hour to the chart time every week before the 15th and subtract a half hour for every week after the 15th.
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
- Follow the arc of the handle of the Big Dipper to the star Arcturus
- The Summer Triangle is outlined in red. Vega in Lyra (Lyr), Deneb in Cygnus (Cyg) and Altair in Aquila (Aql).
Calendar of Planetary Events
Credit: Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC)
To generate your own calendar go to http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html
Times are Eastern Time.
Date Time Event
Sep 01 Th Venus: 23.5° E
01 Th 5:03 am New Moon
01 Th 5:08 am Annular Solar Eclipse (Atlantic, Africa, Indian Ocean)
01 Th 11:27 am Moon Ascending Node
02 Fr 11:16 am Neptune Opposition
03 Sa 6:33 am Moon-Venus: 1.2° S
04 Su 8:03 pm Saturn-Antares: 6.1° N
06 Tu 2:44 pm Moon Apogee: 405100 km
08 Th 5:23 pm Moon-Saturn: 4.2° S
09 Fr 7:49 am First Quarter
10 Sa 6:05 am Moon South Dec.: 18.5° S
12 Mo 7:38 am Mercury Inferior Solar Conjunction (Will enter the
morning sky)
15 Th 7:55 pm Moon Descending Node
16 Fr 2:56 pm Penumbral Lunar Eclipse (Not visible in MI)
16 Fr 3:05 pm Full Harvest Moon
18 Su 11:12 am Venus-Spica: 2.4° N
18 Su 1:00 pm Moon Perigee: 361900 km
21 We 6:13 pm Moon-Aldebaran: 0.2° S
22 Th 10:21 am Autumnal Equinox (Summer ends and autumn starts)
23 Fr 5:56 am Last Quarter
23 Fr 12:44 pm Moon North Dec.: 18.5° N
26 Mo 2:19 am Jupiter Solar Conjunction (Will enter the morning sky)
27 Tu 6:32 pm Moon-Regulus: 1.8° N
28 We 2:59 pm Mercury Greatest Elongation: 17.9° W
28 We 6:06 pm Moon Ascending Node
30 Fr 8:12 pm New Moon (Second new Moon this month)
Oct 01 Sa Venus: 30.9° E
09/22/2015 – Ephemeris – Equinox tomorrow and September 27th Moon’s triple whammy
Ephemeris for Tuesday, September 22nd. The Sun will rise at 7:29. It’ll be up for 12 hours and 11 minutes, setting at 7:40. The Moon, 1 day past first quarter, will set at 2:02 tomorrow morning.
Tomorrow at 4:20 a.m. before most of us wake up summer will officially end and Autumn will start. That’s the exact time of the autumnal equinox. We are noticing that the days or rather daylight hours are getting noticeably shorter day by day. Autumn will end when the days will stop getting shorter on the first day of winter, December 21st. The full moon this Sunday is triply important. Most important is that a total lunar eclipse will happen. Second, it is the Harvest Moon, the nearest full moon to the autumnal equinox, more on that next week. Also it is the closest the Moon gets to the Earth all year. Yup it’s a so-called supermoon. If the Moon were a 2 inch ball it would be 20 feet from an 8 inch Earth. The supermoon is a foot closer.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
That last bit about the Moon being a two-inch ball will come in handy if you come to the Girl Scout Badge Bash at ECCO in Traverse City Thursday night.
Bob Moler's Ephemeris Blog 