December Skies

by Dick Cookman

December 10, 2024

Highlights: Comet Journal, Martian Landers, Meteor Showers, Planet Plotting, November Moon

Focus Constellations: Ursa Major, Draco, Ursa Minor, Camelopardalis, Lynx, Gemini, Auriga, Taurus, Perseus, Cassiopeia, Cepheus, Pegasus, Andromeda, Triangulum, Aries, Pisces

Comet Journals

Comet C/2023 A3 (Tsuchinshan-ATLAS) is rapidly dimming at 9th magnitude in Aquila in early December. It is over 2 astronomical units away and and is leaving the inner solar system as it retreats to the Oort Belt. It is best observed with a telescope low in the western early evening sky.

Comet 333P/LINEAR A3 is a 10th magnitude short period comet moving southeasterly from Canes Venatici to Cygnus in December. Perihelion passage was on Nov. 29 and it will be closest to Earth on Jan. 11 when it reaches 9th magnitude.

Mars Landers

The path less traveled: Robert Schreiber, writing for marsdaily.com reported on a recent article published in “Nature” by astrobiologist Dirk Schultze-Mapuche which questioned the current experimental approach for seeking Martian life. According to the article, investigations “designed with Earth-centric assumptions about life’s needs, might have missed key opportunities by overlooking Martian extremophiles – organisms potentially thriving in environments starkly different from any on Earth.” Schultze-Mapuche suggests that experiments designed to find life in areas on Earth like the “the hyperarid core of the Atacama Desert and Antarctica’s Dry Valleys” might be more appropriate. Although the current approach may be well suited for finding evidence for ancient Martian life existing when Mars was warm and wet, it “could have been fatal for any existing Martian life, which might be highly sensitive to excess water.” He proposes that “Mars missions should prioritize the search for life within salts and other hygroscopic compounds, which might harbor microbial communities.”

Meteor Showers

The three northern hemisphere meteor showers in December include the Geminids, Ursids, and Coma Berenicids in order of date and abundance. The Geminids will be diminished by competition with the waxing gibbous Moon, the Ursids must deal with the nearby last quarter Moon.

• December 13: Geminids. Active Dec. 7-Dec. 17. Radiant 7h28m +33°. ZHR 120. 35 km/sec. Waning Gibbous Moon. Progenitor: Asteroid 3200 Phaethon.
• December 22: Ursids. Active Dec. 17-Dec. 26. Radiant 14h28m +76°. ZHR 10, variable to 50+. 33 km/sec. Waning Crescent Moon. Progenitor: Comet 8P/Tuttle.
• December 29: Coma Berenicids. Active Dec. 12-Jan 23. Radiant 11h40m +25°. ZHR 5. 65 km/sec. Waning Crescent Moon. Progenitor: Comet Lowe.

Planet Plottings

December’s evening planets include Venus (-4.1 to -4.2) in Sagittarius and Aquarius, Saturn (1.0 to 1.1) in Aquarius, Neptune (7.9) in Pisces), Uranus (5.6 to 5.7) in Taurus, Jupiter (-2.7 to -2.6) in Taurus, and Mars (-0.5 to -1.2) in Cancer. On the 1st, as Mars rises, Venus is setting in the west-southwest about 8:00PM EST, Saturn follows Venus slightly after 11PM EST, and Neptune sets soon after midnight. Uranus and Jupiter set well before dawn and Mars is visible almost all night as it approaches its January opposition. Almost 20 hours after New Moon on the 1st, Mercury is less than 5° from a very thin waxing crescent Moon which will then pass Venus on the 4th. After its inferior conjunction with the Sun on the 5th, Mercury will appear low in the southeastern morning sky and will reach greatest western elongation (22° from the Sun) on the 24th, four days before it is passed by the waning crescent Moon. The 1st quarter Moon passes Saturn on the 8th and the waxing gibbous Moon passes Neptune on the 9th, Uranus on the 13th, and Jupiter on the 14th. After the full Yule Moon on the 15th, the waning gibbous Moon passes Mars on the18th. Jupiter is at opposition on the 7th when Earth is directly between the Sun and Jupiter which is at its brightest for 2024 and is high in southern sky at midnight, providing northern observers their best view of the giant planet in the last ten years. Jupiter bedazzles the heavens after sunset, dominating the seven surrounding 1st magnitude stars decorating the eastern mid-evening skies.

December Moon

The 1st New Moon of December is in Scorpius on the 1st at 1:21AM EDT. This New Moon marks the start of Lunation 1261 which ends 29.67 days later with the 2nd New Moon of December in Sagittarius on the 30th at 5:27PM EST. The Full Moon on the 15th occurs at 4:02AM EST in Taurus. It is the Moon before Yule or Long Night’s Moon. Colonial Americans called it the “Christmas Moon”. To the Celts it was the “Cold Moon”, and it is the “Bitter Moon” for the Chinese. Medieval English thought of it as the “Oak Moon”, and the Anishinaabe (Odawa and Ojibwe) people of northern Michigan recognize it as “Manidoo-Giizisoons” (Little Spirit Moon).

Ontario’s Earth Haven Farm presents cultural teachings explaining the cycle of life and nature of the 13 Grandmother Moons. “The twelfth moon of Creation is the Little Spirit Moon, a time of healing. By receiving both vision of the spirits and good health, we may walk the Red Road with purest intentions, and we can share this most positive energy with our families and friends for the good of all.”

The December 30 New Moon marks the start of lunation 1262, the 13th moon of 2024! The thirteenth moon of Creation is Big Spirit Moon. Its purpose is to purify us, and to heal all of Creation, a process which may take a three month long spiritual journey. During this time, we receive instructions on the healing powers of the universe and transform into our own vision of the truth.

Lunar perigee – Dec.12, 8:20AM EST. The Moon is at 227,025 mi. (57.28 Earth radii). Lunar Apogee (maximum lunar distance) – Dec. 24 at 2:25AM EST. Lunar distance is 251,335mi. (63.42 Earth radii).