Skywatch Line for Friday, December 6, through Sunday, December 8, written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, December 6, through Sunday, December 8, written by Sam Salem.
On Friday, Sun rises at 7:12am and sets at 4:21pm; Moon rises at 11:38am and sets at 9:46pm.
These days have the earliest sunset of the year. By the time of the solstice and longest night on December 21st, the Sun sets 3 minutes later than it does now. The latest sunrise doesnt come until the end the end of December/early January. These slight discrepancies arise from the tilt of Earth’s axis and the ellipticity of Earth’s orbit.
On Friday, the waxing crescent Moon will move away from Venus after sunset.
Venus, magnitude –4.2, crossing the Capricornus-Sagittarius border, gleams in the southwest in evening twilight. It remains up for nearly 1½ hours after dark. Venus will reach its greatest distance from the Sun in January 2025.
First-quarter Moon occurs at 10:27am on Sunday. The Moon shines upper left of Saturn this evening. The bright star Fomalhaut, the loneliest star, is nearby. They’ll set around midnight. Saturn rings are closing now. By March of 2025, they’ll be so perfectly edgewise that, for a time, they’ll disappear.
Saturn, magnitude +1.0 in Aquarius, glows highest in the south soon after dark. Fomalhaut twinkling two fists below it. Saturn is now 45° east of Venus along the ecliptic. Watch them close in on each other toward their conjunction on January 18th, when they’ll pass each other by 2.2°.
Mars, magnitude –0.6, in the constellation of Cancer, rises in the east-northeast around 8pm. It still forms the right angle of a rough right triangle with Castor and Pollux above it and Procyon to its right. Mars is 50° east along the ecliptic from brighter Jupiter.
Mars is very high toward the southeast or south in the hours after midnight. It has enlarged to 12 arcseconds in apparent diameter.
Jupiter is at opposition on Saturday. It shines at a bright magnitude –2.8 in the constellation of Taurus. Spot it low in the east-northeast as twilight fades. As dusk deepens, watch for Aldebaran and slightly fainter El Nath (Beta Tauri) to come into view nearly equidistant to Jupiter’s right and left. Jupiter is very high toward the south in the night’s middle hours. It’s 48 arcseconds wide in a telescope and will remain so for another couple weeks.
On Sunday when the sky is dark, look for the dim Circlet of Pisces less than a fist-width above the Moon. Its stars are only 4th and 5th magnitude. Cover the glary Moon with your finger to help them show. Try binoculars. The Circlet is 7° wide and 5° tall, slightly overspilling the field of view of typical binoculars. Sweep around just a little bit to pick up all seven of the Circlet’s stars.