The Northern Hemisphere’s full Harvest Moon has passed. The moon is now in a waning gibbous phase, rising in the east later and later each evening. That means you can catch the moon over your western horizon after sunrise this weekend. Sylvia asked:
When is the best time to see the moon in the sky during daylight hours?
The answer is that the daytime moon is up there much of the time, but, because it’s pale against the blue sky, it’s not as noticeable as the moon at night. The most noticeable moon at night is a full moon. The recent full moon was on October 5 at 18:40 Universal Time; translate to your time zone. That means the time is now to catch a daytime moon, in the west in the morning.
Every full moon rises around sunset and sets around sunrise. But now the moon is in a waning gibbous phase – rising later each night – and setting in the west later each day after sunrise.
So, in the several mornings after full moon – after sunrise – look for the waning gibbous moon in the west during the morning hours. At mid-northern latitudes in North America, the moon will set well over one hour after sunrise on October 7, 2017, and will set an one hour (or more) later each day thereafter.
By the way, the moon is up during the day half the time. It has to be, since it orbits around the whole Earth once a month. A crescent moon is hard to see because it’s so near the sun in the sky. At the vicinity of last quarter moon about a week from now, you might have to crane your neck, looking up, to notice it after sunrise.
Ordinarily, we don’t look up to see the waning last quarter moon and waning crescent after sunrise. That’s one reason why people so often miss the moon during the day.
Day by day, the lighted portion of the waning gibbous moon will shrink and the half-lit last quarter moon will come on October 12. Watch for the daytime moon to climb higher and higher into the western sky after sunrise all this coming week!
If you do catch the moon in the evening tonight or in the next few nights, notice the stars near it. On October 7, the moon is moving toward the famous dipper-shaped Pleiades star cluster, also known as the Seven Sisters, a major signpost in the constellation Taurus the Bull.
On October 8, the moon will be near the constellation Taurus’ other major signpost, the bright star Aldebaran. In fact, the moon will occult or pass in front of Aldebaran from some parts of the world. Read more about the occultation of Aldebaran.
Bottom line: Starting around October 7, 2017, look for the daytime moon in the west after sunrise.