THE SOUTHWORTH PLANETARIUM

70 Falmouth Street Portland, Maine 04103

43.6667° N 70.2667° W Altitude: 10 feet below sea level Founded January 1970

2021-2022: LVIII

"It's your outlook on life that counts. If you take yourself lightly and don't take yourself too seriously, pretty soon you can find the humor in our everyday lives. And sometimes it can be a lifesaver. " -Betty White

THE DAILY ASTRONOMER

Tuesday, January 4, 2022

January 2022 Night Sky Calendar Part II

THURSDAY, JANUARY 13: MOON NEAR THE PLEIADES

Tonight one will see the waxing gibbous moon (81% illuminated) "near" the Pleiades Star Cluster, also known as the Seven Sisters. The Pleiades will remain visible despite the considerable lunar light interference. During this month's close approach, the moon will appear to move between Taurus the Bull and the Pleiades.

A subscriber recently asked, "Why does the moon pass close to the Pleiades and Praesepe star clusters each month and not some of the others?"

The moon appears to draw close to these clusters because they are both located close to the ecliptic, the Sun's annual path through the sky. As the moon and planets all move within a band centered on this ecliptic, they all appear to move close to stars located on or near it. For instance:

MONDAY, JANUARY 17: MOON NEAR CASTOR AND POLLUX

The full moon passes south of Castor and Pollux, the two brightest stars within the Gemini twins, tonight. In the above image (courtesy: Sky and Telescope), the ecliptic is depicted as a curved blue line extending between the image's left and right border. Since Castor and Pollux are both close to this line, the moon will appear to move close to them each month.

On an unrelated note: the white region centered on Gemini is designated as the Gemini region. When the Sun's position is within this area, it is said to be "in Gemini." Currently, the Sun enters Gemini immediately after the summer solstice and remains within it until about July 20th. The ecliptic intersects thirteen constellation regions. Those thirteen constellations comprise the "zodiac."

MONDAY, JANUARY 17: FULL MOON

January's full moon has its fair share of nicknames: the Snow Moon, the Moon After Yule, the Ice Moon, and the Wolf Moon. While the first three names are sensible, the last one is a bit perplexing. The "Wolf Moon" name likely derives from the Anglo Saxon calendar and relates to the howling of hungry wolves prowling the wilderness in search of food. The full moon provided ample illumination to aid them in their search for nourishment.

TUESDAY, JANUARY 18: MOON NEAR PRAESEPE (BEEHIVE STAR CLUSTER)

See the waning gibbous moon (99% illuminated) close to Praesepe, the prominent star cluster within the constellation Cancer the Crab. The moon's light will likely obscure this cluster entirely.

SUNDAY, JANUARY 23: MERCURY AT INFERIOR SOLAR CONJUNCTION

Now, Mercury passes between the Sun and Earth and will soon appear in the eastern pre-dawn sky. Only the two inferior planets, Mercury and Venus, can ever pass into inferior solar conjunction. As Mercury is in conjunction today, we won't see it. As is true with Venus, we can only see Mercury at inferior conjunction when it passes directly across the Sun, an event called a transit. Recall that the next Venusian transit won't occur until December 11, 2117. We only have to wait until November 13, 2032 for the next transit of Mercury.

To subscribe or unsubscribe from the Daily Astronomer:

https://lists.maine.edu/cgi-bin/wa?SUBED1=DAILY-ASTRONOMER&A=