Posts Tagged ‘Autumnal Equinox’

Oct
05
2009

King Harvest

Caught between the rooftops and an advancing blanket of cloud, Sunday’s Harvest Moon managed to reveal itself for a few brief moments as it rose into the sky. Taking place around the time of the autumnal equinox, the Harvest Moon is unique because it rises 30 rather than 50 minutes later each successive evening.

This happens because the path of the Moon on the ecliptic forms a narrow angle with respect to the horizon. An occurrence which results in shorter rising times with no period of darkness between Sunsets and Moonrises. In times long past this helped farmers, as they could work for much longer, when it became time to gather in their crops. Hence the name of this full Moon.

Harvest Moon Rising 04.10.09: Mouseover the image for a close-up.

The offhand shot above, a 1/40 second exposure, was taken at a focal length of 70mm using an f/stop of 5.6 and an ISO of 100. The image was then processed using a combination of Apple’s Aperture and the open source image editor GIMP.

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Posted in Astrophotography | 2 Comments »

Sep
09
2008

Harvest

Monday the 15th presents a chance to view (weather permitting) a full moon like no other. Due to the affect of the approaching Autumnal Equinox 1 on the 22nd, the full moon will rise around sunset and appear closer to the horizon which will make the moon look bigger whilst possibly imbuing it with a red hue.

As the Earth nears this Equinox, something else unique happens to the moon. The moon rises on average around 50 minutes later each day at sunset but at the nearing of the Autumnal Equinox the moon will rise 30 minutes from one night to the next. This means that there is no period of darkness after sunset. In times gone by this would have helped farmers to bring in their crops by enabling them to work for much longer.

This lunar event is something I am really looking forward to and If I manage to get a good, clear evening I’m planning to try and take some Afocal shots through my 25×100 bins. If the weather holds out for me and my shots are successful you can expect to see my observations on here. Fingers crossed.

  1. At the time of the Autumnal Equinox, the sun’s path across the ecliptic will cross the celestial equator (the imaginary line that separates the northern and southern hemispheres) in the constellation Virgo. During this period the nights become as long as the day, but after this point the days become shorter as the sun begins to shine lower and lower in the sky. Put more simply, when one pole of the Earth is angled towards the sun, that hemisphere receives more hours of daylight. When the same pole is angled away from the sun the same hemisphere receives less hours of daylight. ↩

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