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Ephemeris: 10/06/2025 – Tonight’s full moon is the Harvest Moon!
This is Ephemeris for Monday, 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, at full today, will rise at 6:53 this evening.
Today’s full moon is the nearest full moon to the autumnal equinox which makes it the Harvest Moon. Normally, October’s full moon is called the Hunter’s Moon, so it can be both at the same time. The indigenous peoples of our area, the Anishinaabe, call it the Falling Leaves Moon and indeed this month the leaves will fall from deciduous trees, after giving us a couple of weeks of spectacular color. The exact time that the moon will be full will be 11:48 PM this evening. Therefore, the Moon is going to rise very close to sunset. As a matter of fact, it will rise 20 minutes before sunset, so it should be a very spectacular rising of an orangish moon which, this time of year, will remind one of a pumpkin.
The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.
Addendum
Ephemeris: 09/19/2024 – The Chinese Mid-Autumn Festival
This is Ephemeris for Thursday, September 19th. Today the Sun will be up for 12 hours and 17 minutes, setting at 7:44, and it will rise tomorrow at 7:28. The Moon, 2 days past full, will rise at 8:30 this evening.
Our Harvest Moon also marks the Chinese Mid-Autumn Festival. I’ve been too busy with the lunar eclipse to cover it on Tuesday. It is to honor the Moon and the story of Chang’e a mortal woman who took an elixir and flew off to the Moon and became a goddess. Another story revolves around the Jade Rabbit pounding Medicine. I sometimes talk about the figure of a rabbit seen on the face of the Moon. He is a companion to Chang’e, and has a mortar and pestle on the Moon with him. He pounds out the medicine that makes the inhabitants of the sky immortal. The Chinese lunar probes are named Chang’e. Chang’e 3 landed on the Moon in 2013 and sent out a lunar rover named Yutu, the Jade Rabbit. They have made other landings since.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Addendum
Ephemeris: 09/17/2024 – Super Harvest Moon Eclipse tonight
Note: the eclipse isn’t that super, however tonight’s full moon is a supermoon, and the Harvest Moon to boot. On with the program.
This is Ephemeris for Tuesday, September 17th. Today the Sun will be up for 12 hours and 23 minutes, setting at 7:48, and it will rise tomorrow at 7:25. The Moon, at full today, will rise at 7:47 this evening.
Tonight’s full Harvest Moon* is also a supermoon and on top of that it will be partially eclipsed in Earth’s shadow. The Moon will just clip the bottom or south part of the Earth’s inner shadow called the umbra between 10:13 PM and 11:15 PM. Only 8% of the Moon’s diameter will be covered by the umbra at maximum eclipse at 10:44 PM. However, the Moon will spend a fair amount of time in the Earth’s penumbra, the outer part of the shadow, where the Sun is only partially blocked. So the moon will appear dimmer than normal at its upper parts from about 9:45 to 11:45 PM or so. Viewing the moon through a pair of sunglasses will enhance the effects of the dimming of the penumbra, cutting down the Moon’s glare.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
* The Harvest Moon is the full moon nearest the date of the autumnal equinox which this year is on the 22nd of September. What makes the Harvest Moon special is the Harvest Moon Effect. Check it out this previous post where I explained more about it: Here
Addendum
Ephemeris: 09/16/2024 – Quadruple lunar events tomorrow night!
This is Ephemeris for Monday, September 16th. Today the Sun will be up for 12 hours and 26 minutes, setting at 7:50, and it will rise tomorrow at 7:24. The Moon, 1 day before full, will set at 6:34 tomorrow morning.
Tomorrow night there will be 4 lunar events occurring at the same time. Coincidence? I think not. The Moon will be full. The other events can only occur at full moon. It’s the Harvest Moon, the closest full moon to the autumnal equinox. It also happens to be a supermoon with the Moon reaching perigee, it’s closest to the Earth of the month a few hours later. Finally, the Moon will be partially eclipsed. By 9:45 PM the Moon may appear somewhat duller to the upper left than to the lower right. This is the Moon deep inside the Earth’s outer shadow called the penumbra. The actual partial phase of the eclipse will occur from 10:13 PM to 11:16 PM with the maximum occurring at 10:44 PM. With only 8 1/2 % of the Moon’s diameter covered.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.
Addendum
The eclipse will be visible in whole or in part for North America except for extreme western Alaska, also South America, Europe, Africa, and Western Asia. The times in Universal Time (UT): September 18, 2024, first contact 02:13, mid-eclipse 02:44, last contact 03:15.
09/09/2022 – Ephemeris – Observe the Harvest Moon at the Sleeping Bear Dunes Saturday night (weather permitting)
Update 9/10/2022, 6 pm: The weather does not permit it! We’ll have another, again weather permitting, on September 24th. This time with dark skies and a look at the summer Milky Way, two days after the end of summer. (It still counts).
This is Ephemeris for Friday, September 9th. Today the Sun will be up for 12 hours and 49 minutes, setting at 8:04, and it will rise tomorrow at 7:15. The Moon, 1 day before full, will set at 7:14 tomorrow morning.
Tomorrow night, September 10th, there will be, weather permitting, a star party at Sleeping Bear Dunes National Lakeshore, this will take place at the Dune Climb. Actually, it will be mostly a Moon and planet party. The event will be made possible by the rangers of the park and the Grand Traverse Astronomical Society. The society’s and member’s telescopes will take over the parking lot closest to the Dunes. The event starts at 8 p.m., near sunset, while it’s still light out and the location can be found. The Moon will join the party, rising at 8:41 pm. Oh, and it’s a supermoon. There will be a short talk about Harvest Moon lore and why it was important. See if you can find the Man in the Moon and the Chinese rabbit pounding medicine.
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 Harvest Moon with Jupiter and Saturn at 9 pm, September 10, 2022. Created using Stellarium.
09/08/2022 – Ephemeris – We are going to have an early Harvest Moon this year
This is Bob Moler with Ephemeris for Thursday, September 8th. Today the Sun will be up for 12 hours and 53 minutes, setting at 8:06, and it will rise tomorrow at 7:14. The Moon, 2 days before full, will set at 5:54 tomorrow morning.
We are going to have an early Harvest Moon this year, on the early morning of Saturday the 10th, this Saturday coming up. The Harvest Moon is the closest full moon to the autumnal equinox, which is on the 22nd. The earliest a Harvest Moon can fall is on the 8th of September. The reason that the Harvest Moon is so famous is that at sunset the Moon’s path, in the sky, is shallow to the horizon. So it rises much less than its average 50 minutes later each night. This effectively lengthens the amount of useful twilight, allowing more time to harvest the crops. It compensated for the rapid retreat of the daylight hours this time of year. It’s not so important now, but back before electric lights it definitely was.
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 Harvest Moon rising as seen in Stellarium. The planetarium program Stellarium, which I use a lot, also colors the rising and setting Moon and Sun. It also reproduces the effect of atmospheric refraction, which makes objects close to the horizon look higher than they are. Thus, extended objects close to the horizon appear squashed a bit vertically.
The Harvest Moon effect is a phenomenon where the Moon’s nightly advance in rising times become much shorter than the average 50 minutes. This has the effect of extending the bright part of twilight for up to a week near the Harvest Moon. Complicating effects this year are the fact that the Harvest Moon is a supermoon, being a bit brighter than normal, and also moving faster than normal, negating the harvest moon effect somewhat. The Moon’s perigee was on the 7th, so the Moon is slowing down*, which shows in the delay numbers. Also helping to shorten the delay is that the path of the Moon is a bit shallower than the ecliptic. The Moon is south of the ecliptic, heading northward to its ascending node.
The Moon moves fastest in its orbit at perigee, and its slowest at apogee, at its farthest from the Earth.
09/20/2021 – Ephemeris – The Harvest Moon rises tonight
This is Ephemeris for Monday, September 20th. Today the Sun will be up for 12 hours and 15 minutes, setting at 7:43, and it will rise tomorrow at 7:29. The Moon, at full today, will rise at 8:03 this evening.
Tonight’s full moon is the Harvest Moon. It is the most famous of the named full moons, and was very useful in the days before electric lights. The reason is that the Moon, around the time it is full now, doesn’t advance its rising time very much from night to night, effectively extending the light of twilight to allow more time to gather in crops. This is because the Moon is moving north as well as eastward. The farther north it is, the longer it stays up and retards the advance in rise times. On average, the Moon rises 50 minutes later each night. This week, the interval is down near 20 minutes advance in moonrise times per day, extending twilight and the time each day to harvest the crops for a few more days.
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
The autumn vs spring sunset ecliptic. I’m using the autumnal equinox 2021, with the tip of the spout of the Sagittarius Teapot at due south, and vernal equinox 2022, with the red star Betelgeuse in Orion at due south as examples. Click on the image to enlarge it. Created using Stellarium and GIMP.
The ecliptic for the autumnal equinox runs low in the south, a preview of the Sun’s apparent travel for the next six months of fall and winter. Besides the planets, the Moon at sticks close to that line, as do the planets. The full moon rising in the east as the Sun sets does so at a shallow angle, so for a week or so around the full moon, its advance in rise times can be as little as 20 minutes per night. In spring, it can be much longer than an hour.
09/29/2020 – Ephemeris – The Harvest Moon is in two days
This is Ephemeris for Tuesday, September 29th. Today the Sun will be up for 11 hours and 47 minutes, setting at 7:26, and it will rise tomorrow at 7:40. The Moon, 2 days before full, will set at 6:09 tomorrow morning.
This upcoming full moon is the Harvest Moon. It is the most famous of the named full moons, and was very useful in the days before electric lights. The reason is that the Moon, around the time it is full now doesn’t advance its rising time very much from night to night effectively extending the light of twilight to allow more time to gather in crops. This is because the Moon is moving north as well as eastward. The farther north it is the longer it stays up and retards the advance in rise times. On average the Moon rises 50 minutes later each night. This week the interval is down near 20 minutes advance in moonrise times per day extending twilight and the time each day to harvest the crops for a few more days.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The motion of the moon from tonight through next Monday night. This is looking east at where the Moon will rise, and we’re able to see below the horizon. The celestial equator, a projection of the Earth’s equator on the sky, crosses the horizon at an angle equal to 90 minus one’s latitude. Around my location that’s 45.5 degrees. The Moon and stars will rise parallel to the celestial equator. Its daily orbital motion is at the shallow angle of 5 degrees to the ecliptic, the apparent path of the Sun. So the advance in rise times starts off at 20 minutes later each night, rather than the average 50 minutes.
09/24/2018 – Ephemeris – The harvest moon and the Chinese Mid-Autumn Festival
Ephemeris for Monday, September 24th. The Sun will rise at 7:32. It’ll be up for 12 hours and 4 minutes, setting at 7:36. The Moon, at full today, will rise at 7:51 this evening.
Tonight at 10:53 p.m. the Moon will be full. And since it’s only two days past the autumnal equinox, this makes it the Harvest Moon. This full moon also marks the Chinese Mid-Autumn Festival to honor the Moon and the story of Chang’e a mortal woman to took an elixir and flew off to the Moon and became a goddess. Another story revolves around the Jade Rabbit pounding Medicine. I talked about the figure of a rabbit seen on the face of the Moon last Monday. He is a companion to Chang’e, and has a mortar on the Moon with him. He pounds out the medicine that makes the inhabitants of the sky immortal. The Chinese lunar probes are named Chang’e. Chang’e 3 landed on the Moon in 2013 and sent out a lunar rover named Yutu , the Jade Rabbit.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Chang’e 3 Lander on the Moon. Credit China National Space Administration 
Yutu Rover on the Moon. Credit China National Space Administration.
08/27/2018 – Ephemeris – It wasn’t the Harvest Moon but it has that effect
Ephemeris for Monday, August 27th. The Sun will rise at 6:59. It’ll be up for 13 hours and 29 minutes, setting at 8:28. The Moon, 1 day past full, will rise at 9:21 this evening.
Last night’s full moon wasn’t the Harvest Moon. That’s next month’s full moon. This full moon is the Sturgeon Full Moon. You’d think it should be the Corn Moon, That’s normally the September’s full moon, which is preempted this year by the Harvest Moon, the closest full moon to the autumnal equinox. What’s taking effect now is what I call the harvest moon effect, in that the nearly full Moon stays in the evening sky for almost a week, it seems, after full; while I’m waiting to spot the wonders of the summer Milky Way at a decent hour. On average the Moon rises about 50 minutes later each night. Now it’s decreasing to be less than 30 minutes. It won’t be until Thursday night that we’ll have a whole half hour of dark skies, and up to an hour by Friday night.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The motion of the Moon with respect to the eastern horizon from August 27 through August 31, 2018. It shows the difference in the rise times that create the harvest moon effect. Created using Cartes du Ciel (Sky Charts).
Bob Moler's Ephemeris Blog 