In early August, Mars, Saturn and Spica formed a triangle. Credit: John Chumack
The Harvest Moon, which is defined as the Full Moon closest to the autumnal equinox, can occur in September or October. Most years the Harvest Moon is in September, as it is in 2012. The equinox, and therefore the first day of fall, lands on September 22 at 7:49 a.m. Pacific Time. With days and nights of equal length, the sun rises directly in the east and sets directly in the west. The closest Full Moon to this date is on September 29. The Harvest Moon rises in the east just before it hits 100 percent illumination at 8:19 p.m. pacific.
Moonrise in September occurs as little as a half hour apart from night to night as opposed to other times of the year when moonrise from one night to the next can fall more than an hour apart. The full and nearly full moons after sunset in September provided the extra light for farmers in the fields and earned this moon the name of Harvest Moon.
The planet Uranus reaches opposition, or opposite the sun in the sky when it rises at sunset and sets at sunrise, on the same night as the Full Moon, September 29. Normally opposition is considered the best time to observe a planet, but when it occurs simultaneously with a Full Moon in the same region of sky, this is not the case. The moon will be just four degrees above Uranus, washing out the sky around the dim planet.