Moon Day!

Well, it’s July and time to commemorate again one of the most significant events in all of human history.  Actually, many including some historians consider it to be the most significant event.  We’re referring, of course, to the famed Apollo 11 Moon landing on July 20th, 1969, when people left their home on Planet Earth and journeyed to another world in space.

For some time now I have personally been campaigning to have this historic event officially recognized as a national holiday.  My premise is that if there’s a Columbus Day on the calendar, there certainly should be a Moon Day!  Columbus set foot on another continent—but the Apollo astronauts set foot on another world!  While this suggestion has been under consideration on several fronts, nothing has developed so far to make it happen.

There are at least two ways to celebrate this occasion.  A “public” one is to remind everyone you can about it by greeting them with “Happy Moon Day!”  This includes family members, relatives, neighbors, teachers, fellow workers, folks at checkout counters, and maybe even a legislator or two you happen to personally know.  The reaction you get may be a knowing look and smile—or a puzzled look, which then opens an opportunity to explain what you mean.  I always enjoy doing this all day and evening long every July 20th!

A second personal way is to make a point of actually observing the Moon itself sometime this month.  On the night of the Apollo landing, the Moon was about a 35% crescent—or slightly less than half-full.  Many wonder why NASA didn’t pick a Full-Moon for the landing, but they did have a very important reason for choosing the phase they did.  On July 20th, 1969, the Sun had just risen on the chosen landing site in the Sea of Tranquility.  That low Sun cast long dark shadows of craters, boulders, and uneven surfaces on the Moon—features that would be hazards for a landing and which would be far less perceptible if the Sun were overhead.

To see the location of the landing site, look about halfway down from the top of the Moon and a third of the way in from the right hand edge.  This month our lovely “Queen of the Night” will be at approximately same phase as it was that July 20th on the night of the 15th into the morning hours of the 16th.  But any time around Full-Moon works well—it occurs on the evening of July 23rd into the morning hours of the 24th.    While you can gaze at the Moon to locate landing area with the unaided-eye, the best view is with binoculars, which makes the spot more definite.  And it’s enough optical aid that still shows the Moon with lots of sky around it, giving the impression that it’s floating in space—which, of course, it is!   The 3-D illusion of depth perception provided by using both eyes with such glasses makes this even more real.


— James Mullaney

Former assistant editor at Sky & Telescope magazine & author of nine books on stargazing. His latest, Celebrating the Universe!, is available from