The Full Hunter's Moon
October 14, 2008

The Hunter's Moon (also known as Blood Moon or Sanguine Moon) is the first full moon after the harvest moon which is nearest the autumnal equinox.

In general, the moon rises about 50 minutes later each day, as it moves in orbit around Earth. All full moons rise around the time of sunset. The Harvest Moon and Hunter's Moon are special because - as seen from the northern hemisphere - the time of moonrise on successive evenings is shorter than usual. The moon rises approximately 30 minutes later, from one night to the next, as seen from about 40 degrees N. latitude, for several evenings around the full Hunter's or Harvest Moons.

Thus there is no long period of darkness between sunset and moonrise, around the time of these full moons. In times past, this feature of these autumn moons was said to help hunters tracking their prey (or, in the case of the Harvest Moon, farmers working in the fields). They could continue tracking their prey (or bringing in their crops) by moonlight even when the sun had gone down. Hence the name Hunter's (or Harvest) Moon.

The reason for the shorter-than-usual rising time between successive moonrises around the time of the Harvest and Hunter's Moon is that the orbit of the Moon makes a narrow angle with respect to the horizon in the evening in autumn, leading the Moon to higher positions in the sky each successive day.