Simma Sky: Harvest Moon & September Bright Planets


September started off with a “bang” sky-wise. The full moon on September 2nd brought some heavenly views. September’s full moon is typically called the “Harvest Moon” but not this year. The Harvest moon is the full moon that occurs closest to the Autumnal Equinox. The equinox occurs on September 22, so you would think September’s full moon would be “Harvest,” right? Nope. The full moon occurring during the calendar month of September occurs 20 days before the equinox. October’s full moon happens on the first of the month. I’ll do the math for ya - that’s only 9 days away. Therefore, the 2020 Harvest Moon occurs in October (and there are actually TWO full moons in October - it’s a blue moon! More discussion to come next month. The Harvest Moon gets moved about every three years according to TimeAndDate.

If it’s not a Harvest Moon, what was it? September’s full moon was merely known as “Corn” Moon or “Barley” Moon. Brian in St. Augustine Beach got this great view of it:

In case you need a refresher, the Equinox is the day with 12 hours of night and 12 hours of day (not exactly, but really close). It’s the start of fall for the Northern Hemisphere.


Mars, Venus, Jupiter, Saturn, and even Mercury show some dazzling displays with the moon this month. EarthSky does a great job detailing all of them, but I’m going to focus on two.

Venus dances with the Crescent Moon around the dates of September 13-15. We saw Venus earlier this year and even last year get really close to the Crescent Moon at times in the evening, and she’s doing it again. Except this time it’s in the morning. The Crescent Moon is waning here, so it gets thinner and thinner and gradually lower each morning. Venus will be unmistakable to spot. Look east about one hour before sunrise each of those mornings.

Also look out for Jupiter and Saturn to do some close moving with the moon. Toward the back half of the month, centered around September 24-25, look south at Dusk. The moon will be “waxing” at this point, or getting larger each night. Jupiter and Saturn will be close to each other from Earth’s perspective, and the moon will be right there. Should be good.