Full moon setting south of west

Event Date: June 4th
Time: 4:12 AM


Brief

   Yesterday I was showing the Moon rising and how it had passed ascending node earlier in the day.
Now, less than 9 hours later, I show it at the crest of fullness, shortly before setting.  This duration between entries also reminds what I said yesterday about (near-)full moons only above the horizon for between 9-10 hours above the horizon when viewed from our latitude; such being the case during late spring and early Summer months.  Look at where the Moon is near the ecliptic in relation to the celestial equator, being several degrees south [of the equator]. 

click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

   Look to the far left of the image, where the Moon's orbit is shown a few degrees north of the ecliptic.  Yesterday while the Moon was shown on the rise, I showed the orbit south of the ecliptic instead.  The way we see the orbit for today's entry at that left side, it shows something else: as the Moon moves to the part of the sky where the Sun is during winter months, its orbit will give it that slight extra "boost" north.  This cycle of north and south of the ecliptic happens about once a revolution for the Moon.  Since its sidereal period of 27 days, 7+ hours puts it at each phase a little further west than the cycle before, that is why in June we see it as full phase well south of the celestial equator; while in December, we see it north of the equator.  Of course, this is partly because of the Moon's movement around us, but also because of our revolution around the Sun.  The full Moon is at opposition with our star, putting it about 6 months before or after the Sun's position in the sky.  Viewed above, we see the Moon slightly west of the galactic center near Sagittarius left of it.  With the Sun located here in early December; the labeling along the ecliptic reminds us of this also, shown in the image.