There won’t be much night tonight with the Full Beaver Moon up. I mean, yes, it will still be night, but if you’ve paid attention to the moon lately, you’ve noticed how much higher it is in the sky in November compared to July. Add in some snow, like what’s out my window, and night resembles day more than dark.
Each month after the summer solstice, the full moon slides about one constellation north in the zodiac. For northern hemisphere skywatchers, that means the moon climbs higher and higher with each passing month until reaching a pinnacle in December-January. Thereafter, it slides one zodiac constellation to the south, bottoming out in June-July. Full moons are always opposite the sun, so if the moon’s high, the sun’s low and vice versa.
I happen to love the seesaw rhythm. Any regular observer of the sky feels this solar-lunar beat in their bones and routinely follows the seasons by the counterbalanced movement of the two bodies.
Tonight’s full moon will shine from an unusual constellation, one in which it only occasionally passes through — Cetus the Sea Monster. If that doesn’t fit in the twelve-pack zodiac mindset, that’s because professional astronomers carefully fixed constellation boundaries back in 1930. This move put a slice of Ophiuchus the Serpent Bearer between the traditional groups, Scorpius and Sagittarius; now the sun spends 18 days a year in Ophiuchus. Many think the stay warrants admission to the zodiac club as the 13th “sign.” Heck, why not?
The moon passes through Ophiuchus and a bunch of other constellations because its orbit is inclined about 5° to the path the sun takes across the sky. Some of those groups lie to the north of the path and some to the south. Cetus is to the south. If you want to see tonight’s moon at the moment it rises — always a wonderful way to spend a half-hour — click here for your local moonrise time.
Keep an eye on the moon this weekend because on Sunday evening, it will occult the bright star Aldebaran. We’ll have more about that event very soon!