waning, gibbous Moon slow to rise

Event Date: February 26th

Time: 7:45 PM

Brief

   The Moon rises sightly over an hour later than yesterday, by about 3 minutes.  As it moves further south quickly over the next few days after that, it is moving in the part of the sky that our Sun does near/at the time of the September equinox.  The Moon's orbit keeps it a few degrees south of the ecliptic for the next few days until reaching ascending node.  It will be seen waning quickly until then and through 3rd quarter.  Seen below at 98% illuminated, it is still very bright as well, washing out that part of the sky which lacks easy-to-see deep sky anyway; it is mostly far away galaxies, which I will get more into when the Moon is out of the way.

Detailed

   As we look at the Moon zoomed in here, with a field of 1º, we can see how the terminator is starting to show again on the western (top) limb.  This is where the Sun is setting therefore casting that slight shadow.  If a person is on the Moon, walking along the same latitude at all times, (s)he can see the Sunset.  Of course, this rate of the shadow rapidly "inching" around the entire disc, takes the same amount of time as one revolution for our satellite with Earth: precisely 29.5 days.  If that same person on the Moon walked along the terminator over the course of this time, (s)he would always see a little Sun over the Moon's horizon.  However, since there is absolutely no atmosphere on the Moon, there is not a blue sky there; just black, with a glare surrounding the Sun.  For when the Sun is not above the horizon, the slow rotation of the Moon means that the stars are seen rising and setting very slowly as well.

   As for our view of the now-waning gibbous, here is the 1º showing, with the terminator.

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

The amount of shadowed surface area of Moon towards our eyes is a "sliver", similar to how we see the Moon just before and after it is new.  It is also how someone on the Moon would view the Earth if far enough out of the Sun's glare.  That is, we are between the two, and most of the light shining towards our daytime side, faces away from a waxing and waning gibbous Moon of 98%.