October 6, 2017 at 10:47 AM
The Harvest Moon rose Thursday night, the full moon closest to the autumnal equinox. Skies were clear in parts of New England, the West and England, but many views were obscured by clouds. If you happened to miss the Harvest Moon on Thursday night, you’ll have another chance to see a similarly beautiful moonrise Friday and Saturday.
As we wrote earlier this week, the Harvest Moon typically occurs in September, but it can be as late as Oct. 7. The name “Harvest Moon” stems from exactly what you’d expect. Its appearance in the sky was a sign to farmers that it was time to bring in the bushels, and it allowed for a longer, brighter twilight. Although that moniker tends to be the most popular thanks to the Celtic and Cherokee traditions, there are many more names for the autumn full moon:
When it first appears on the horizon, the moon may appear slightly orange. When it’s low in the sky, the moon’s light has to pass through a very thick layer of the atmosphere — much thicker than what it passes through when the moon is high in the sky. When light passes through a large distance in Earth’s atmosphere, the particles in the air scatter blue light away and let yellow, orange and red through.
If you missed it Thursday, it will be just as beautiful Friday and Saturday night due to the special timing of moonrise.
A full moon inherently rises very near the time of sunset, since a full moon must be exactly opposite the sun to be fully illuminated. An average moon rises about an hour later each night, but near the autumnal equinox, that timing is much shorter due to the moon’s path in the sky this time of year.
What it translates to for us on the ground is a moonrise that’s only about 30 minutes later each night. The moon will be rising closer to sunset, when the sky is still glowing with twilight, and the moon will still have that beautiful orange-y glow.