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Posts Tagged ‘Harvest Moon’

10/05/2014 – Ephemeris – The Harvest Moon

October 5, 2017 Comments off

This is Bob Moler with Ephemeris for Thursday, October 5th. The Sun will rise at 7:45. It’ll be up for 11 hours and 29 minutes, setting at 7:15. The Moon, at full today, will rise at 7:38 this evening.

This is the day of the Harvest Moon. It will rise just before sunset and colored like a huge pumpkin. The huge size is an optical illusion, and the coloring is courtesy of our Earth’s atmosphere selectively bleeding out the blue from the Moon’s light. The reason the Harvest Moon is so special is that during this period the Moon rises for quite a few days just before and in twilight, effectively lengthening the hours of light that farmers can have to harvest their crops. Tomorrow the Moon will rise 32 minutes later than tonight, rather than the average 50 minutes. The effect is a bit diminished this year because the Moon is nearing perigee, its closest to the Earth and is traveling a bit faster than average. The Moon can get down to a 25 minute day-to-day difference.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Harvest Moon

The position of the Moon for 7 nights centered on moon rise tonight (10/04/2017). The rotation of the Earth carries the Moon to rise parallel to the green celestial equator line. The brown area at the bottom is below the horizon. Click on the image to enlarge. Created using Cartes du Ciel (Sky Charts).

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08/08/2017 – Ephemeris – The Harvest Moon effect starts showing up 2 months early

August 8, 2017 1 comment

Ephemeris for Tuesday, August 8th. The Sun rises at 6:37. It’ll be up for 14 hours and 20 minutes, setting at 8:58. The Moon, 1 day past full, will rise at 9:34 this evening.

The Harvest moon is nearly 2 months away, but some of its effects are starting to be felt now. I call it the Harvest Moon Effect. The Harvest Moon is a bit late this year, October 5th. It’s defined as the nearest full moon to the autumnal equinox. However from August to October the rising times of the full Moon and nights after for the next week don’t advance very fast. On average the Moon rises 50 minutes later each night. Between tonight and tomorrow night the interval will be 32 minutes. This is kind of a bummer this weekend when the Perseid meteor shower reaches peak. As with most meteor showers, the most meteors seen are after midnight. Saturday night’s Perseid peak has the Moon, six days after full rising at 11:36 p.m.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Moonrise time intervals for the rest of this week:

Date Moonrise Difference
08/08/17 9:34 p.m.
32 minutes
08/09/17 10:06 p.m.
30 minutes
08/10/17 10:36 p.m.
30 minutes
08/11/17 11:06 p.m.
30 minutes
08/12/17 11:36 p.m.
Harvest Moon Effect

Harvest Moon Effect for this week. Note how shallow the path of the Moon is in relation to the eastern horizon. I’ve made the earth transparent so we can see the Moon below the horizon. As the Earth rotates the Moon will rise in a direction parallel to the celestial equator. In contrast the Moon’s path around March is steeper than average, so the interval in consecutive lunar rise times is much longer than the 50 minute average. Created using Cartes du Ciel (Sky Charts).

09/16/2016 – Ephemeris – The Harvest Moon is slightly eclipsed for everyone but the Americas

September 16, 2016 Comments off

Ephemeris for Friday, September 16th.  The Sun will rise at 7:23.  It’ll be up for 12 hours and 27 minutes, setting at 7:50.  The Moon, at full today, will rise at 7:59 this evening.

Tonight’s full Moon is the Harvest Moon, the nearest full Moon to the autumnal equinox.  For the next few nights the Moon will rise later each night by much less than the average 50 minutes later each night effectively lengthening twilight for those gathering in crops.  Also this afternoon there will be a penumbral lunar eclipse visible, well not here in Michigan… because the Moon won’t be up.   Actually just about the whole world except North America and most of South America will be able to see the eclipse.  A penumbral eclipse is what I call a 5 o’clock shadow eclipse.  You wouldn’t know it unless someone pointed it out to you, when the Moon dips into the Earth’s outer shadow and the sunlight falling part of it is diminished by a little bit.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Moonlight on the bay

The not so full Moon of Monday night and its reflection on the waters of Suttons Bay after the schooner Inland Seas docked after an evening sail. Credit: the author.

Penumbral eclipse 9/16/2016

The penumbral eclipse of the Moon centered on 2:25 p.m. Eastern time, 18:54 UT, for an hour and a half before and after. Only near the middle of the eclipse will anything be visible of the effect. I find that wearing sunglasses reduces the brightness of the moon and enhances the penumbral shadow. Credit: NASA/GSFC/ Fred Espenak.

For the full-page pdf of the above click here: http://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2016Sep16N.pdf

09/28/2015 – Ephemeris – The Harvest Moon effect

September 28, 2015 Comments off

Ephemeris for Monday, September 28th.  The Sun will rise at 7:36.  It’ll be up for 11 hours and 52 minutes, setting at 7:29.   The Moon, 1 day past full, will rise at 8:00 this evening.

Yesterday’s full moon was the famous Harvest Moon, the nearest full moon to the autumnal equinox.  This is a time of the full and waning gibbous moons in the next few days rising in twilight.  In the old days before electric lights it helped farmers by effectively lengthening the hours of light to gather in the crops.  The Moon on average rises 50 minutes later each night.  The interval between tonight’s moon rise and tomorrow’s will be 38 minutes.  The interval between Tuesday and Wednesday will be 42 minutes.  This year’s harvest moon effect is spoiled a bit because the Moon was at perigee Sunday, the so-called supermoon, so it’s moving faster in its orbit than average.  Like the Sun, the Moon always appears orange or red near the horizon.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Path of the Harvest Moon

The positions of the Moon from September 28 to October 1, 2015. Note the path of the Moon. At Harvest Moon in northern Michigan time it makes less than a 45 degree angle with the horizon. For other latitudes it’s less than (90 – latitude). shorthand term for 90 – latitude is co-latitude. Created using Cartes du Ciel.

The closer to horizontal the Moon’s path is the shorter the difference in night-to-night rise times.

09/22/2015 – Ephemeris – Equinox tomorrow and September 27th Moon’s triple whammy

September 22, 2015 Comments off

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.

10/10/14 – Ephemeris – Hunters Moon effect… Same as the Harvest Moon effect

October 10, 2014 Comments off

Ephemeris for Friday, October 10th.  The sun will rise at 7:51.  It’ll be up for 11 hours and 15 minutes, setting at 7:06.   The moon, 2 days past full, will rise at 8:41 this evening.

Let’s talk about the Moon one more time this week.  Wednesday’s lunar eclipse came on the hunter’s moon.  Like the harvest moon, the previous full moon, the bright Moon lingers in the twilit sky.  We are two days past full moon and the Moon rises just before the end of twilight.  50 minutes is the average night to night advance in moon rise times.  Depending on what part of the sky the moon is in, the nightly delay in rise times can be as little as 35 minutes or as long as an hour and 5 minutes.  The  smallest moon rise advance is when the moon is near the constellation Pisces and the longest advance time is when the moon is near Virgo.  It doesn’t matter the season, it’s where the moon is in the sky.  We only notice it when the moon is near full.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.

Addendum (4 p.m.)

Hunter's Moon path

The Hunters/Harvest Moon effect for 2014. Note the shallowness of the Moon’s path. Created using Cartes du Ciel (Sky Charts).

Worm Moon Effect 2014

The Worm (March Full Moon) Moon effect for 2014. Note the the steepness of the Moon’s path. Created using Cartes du Ciel (Sky Charts).

Note that the brown shading on the bottom of the images is below the horizon.  The yellow line is the ecliptic or plane of the Earth’s orbit.  The motion of all the objects in the sky due to the Earth’s rotation is to the upper right parallel to the celestial equator line that crosses the horizon below the E or east compass point.  The red smudge on the ecliptic is the display of the Earth’s shadow for the 5 days of the display.  Note in the top image that early on October 8th the Moon passes through the Earth’s shadow, which gave us the lunar eclipse that morning.  On the Worm Moon image the Moon misses the Earth’s shadow.  However you can see that the Moon is tracking toward the ecliptic.  The next month on April 15th, the Moon did indeed pass through the earth’s shadow, giving us a lunar eclipse that morning.

09/08/2014 – Ephemeris – There’s a super Harvest Moon tonight!

September 8, 2014 Comments off

Ephemeris for Monday, September 8th.  The sun will rise at 7:13.  It’ll be up for 12 hours and 53 minutes, setting at 8:06.   The moon, at full today, will rise at 7:44 this evening.

Tonight’s full moon is the Harvest Moon, being the closest full moon to the autumnal equinox.  It’s about the earliest Harvest Moon on can get in the year, occurring 14 days before the equinox because the moon’s cycle is 29 ½ days, and the autumnal equinox falls on the 22nd not the 23rd as usual.  On top of that it’s another supermoon.  Perigee or the Moon’s closest approach to the Earth of the month occurred yesterday.   We were all oblivious to the fact until some astrologer wrote about it a few years ago.  It’s nice to know.   Actually there’s a supermoon every month but it only nearly coincides with the full moon one to three times a year at consecutive full moons.  Trouble is the Moon always appears bigger near the horizon.  It’s an illusion.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.

Addendum

See here for last month’s discussion about the supermoon.