The Harvest Moon, just setting this morning as I write, reminds me how most of the Moon's names have fallen away with disuse. Not the names on the Moon, such as Mare Tranquilitatis (the Sea of Tranquility) and Sinus Iridum (the Bay of Rainbows), which have held their lunar ground since selenographer Giovanni Riccioli dubbed them in the mid-seventeenth century. I mean the names of the Moon, which predate the telescope's invention and reflect the daily lives of many cultures. I've read that Siberian reindeer herders, for example, recognized the Moon of Water, the Moon of First Leaves, and the Moon of Shedding Antlers. Only full moons, rising at sunset and staying up all night, have ever earned their own seasonal names. The other phases mark the passage of time but don't call so much attention to themselves.
The Harvest Moon still clinging to collective memory sounds quaint as an old love song, though whoever named it favored a work ethic over romance. Arriving as it does toward Summer's end, when the days grow shorter but the crops require farmers to put in longer hours, the Harvest Moon recognizes their plight: It alters the normal interval from one Moonrise to the next, so as to give them more light.
Most of the year, the Moon rises an average of fifty minutes later than it rose the day before. But during autumn in the mid-to-high latitudes of the northern hemisphere, the Moon returns sooner -- less than half an hour later on successive evenings -- letting the work-day continue into the night.
By a more indoor definition, the Harvest Moon is the full Moon closest to the autumnal equinox, which will occur this year on Friday, Sept. 23 at 5:05 a.m. Fall is (almost) here.