September 2024 Full Harvest Moon
This year’s full Harvest Moon on September 17, 2024, has a lot going on. The Moon will look full when it rises at 7:28PM EDT. However, it won’t be an official full Moon until 10:34PM. This is the exact moment the Sun and Moon are on opposite sides of the Earth. When a full moon occurs close to the autumnal equinox its orbital path is making a shallow angle with the horizon causing the Moon to rise relatively soon after sunset for a few days in a row. This means that the Moon will look full and bright all night long from September 16th to 18th.
There are a couple of other things that make this Moon special. First, it’s a supermoon. “Supermoon” is a trendy internet term for what astronomers call a perigean full Moon which is when the full Moon happens at, or very near, the exact time the Moon is closest to Earth during its orbit. The Moon reaches perigee at 9:30AM EDT the morning of September 18th. A supermoon can be a bit larger and brighter but these differences are so small that the eye can’t notice them. Like all full Moons, they appear larger on the horizon because of the Moon illusion. This is the second of four consecutive supermoons this year and the Harvest Moon will be the second closest full Moon of the year.
The second reason this Moon is special is we will be treated to a partial lunar eclipse. This is the first and only time this year the Moon enters the darkest part of Earth’s shadow called the Umbra. Only a tiny portion along the northern part of the Moon will be eclipsed. Most of the time the Moon is moving through the penumbra. The penumbra is the lighter part of Earth’s shadow – the part where the Sun’s light is not entirely blocked. As the eclipse begins you probably won’t notice any color change to the Moon, but as time goes on you should be able to see a subtle shading. As the partial eclipse begins you will be able to see a dark bite being taken out of the Moon. The graphic accompanying this post gives all the important times for the eclipse and shows you what to expect as the eclipse progresses. You can enjoy the eclipse using just your eyes or with binoculars or a telescope if you have them.
The name Harvest Moon seems to have originated in Europe. Just when the days were growing shorter the full Harvest Moon arrived and for several days the moonlight let the farmers have a few more hours to harvest their crops. For us this extra moonlight gives us more time to enjoy this awesome Moon!