Bob Moler's Ephemeris Blog

Ephemeris for Friday, August 31st.  The sun will rise at 7:04.  It’ll be up for 13 hours and 15 minutes, setting at 8:19.   The moon, at full today, will rise at 8:01 this evening.

Tonight’s moon has been dubbed by some to be a Blue Moon.   No the color of the moon isn’t really blue.  But it is as rare as a blue moon.  Let me try to explain.  Currently the label blue Moon is given to the second full moon in a month.  August’s first full moon was on the first.  This blue moon rule wasn’t always the case.  Early American almanacs apparently gave the title of blue moon to the 4th full moon in a season.  So could the moon ever appear blue?  Yes it can.  If seen through a lot of dust in a dust storm.  A totally eclipsed moon can appear very dark and even have a blue tinge if there’s a lot of volcanic ash in the atmosphere.  I’ve seen two of these eclipses and the moon didn’t appear blue to my eyes, but it was so dim the I could barely make it out without binoculars.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.