The Harvest Moon

Every year approximately 12 complete Moon cycles occur, each corresponding to a synodic month, which is about 29.5 days long. The Harvest Moon (viewable tonight) is the full moon occurring closest to the autumnal equinox, which happens to be this Sunday, the 18th. The Harvest Moon is so called because of the extra evening light it provides for harvest crews working late in the fields. This year, the appearance of the Harvest Moon is even more special due to a coinciding Penumbral Lunar Eclipse. Though not quite the spectacle that other types of lunar eclipse afford, the Penumbral Lunar Eclipse is nonetheless a fascinating phenomena caused by the moon's passing through the outer fringe of Earth's shadow, causing a noticeable "smudge" effect on the moon. Fall is finally here! You can watch the full eclipse tonight live (and outside, of course):