Tonight, the beginning of Fall will be marked by the rising of a “Super Harvest Moon”  accompanied by an unusually bright planet Jupiter.

‘Super Harvest Moon’ will usher in autumn tonight

For the first time since 1991, autumn begins tonight with a full moon, an occurrence called a “Super Harvest Moon.”

As the sun sets in the west, the moon will rise in the east, mixing their light to create what NASA calls a “360-degree, summer-autumn twilight glow that is only seen on rare occasions.”

In addition, the moon as it rises may appear larger than normal, due to the poorly understood “moon illusion” that makes it look wider than it does when higher in the sky.

At the exact moment of the autumn equinox, which occurs at 11:09 p.m., the Harvest Moon will be paired with Jupiter, which will be the second brightest object in the sky tonight.

And whatever you do, do not fall asleep to night on deck.  We don’t want anyone struck down by moon-blindness.   Sailors in the nineteenth century warned against sleeping on deck under the moon  for fear of being struck moon-blind.   While it is not a well known condition today, it was discussed in medical journals and texts well into the late nineteenth century.  From Treatise on the diseases of the eye (1873) by Dr. Carl Stellwag(von carion) Professor of Ophthalmology of the Imperial Royal University of Vienna:

Moon-blindness often appears among sailors, when in the tropics, if they sleep on the deck, under the full light of the moon. It sometimes becomes so intense that the patient on awakening can scarcely recognize daylight and must be led about.