This is the Skywatch Line for Monday and Tuesday, January eleventh and twelfth.
The Sun sets at 4:41 PM; night falls at 6:22. Dawn breaks at 5:44 AM and ends with sunrise at 7:29.
The twilight sky has one bright object, the Moon. Monday, the two-day-old Moon is rather low in the western sky and inhabits Aquarius; it shines at minus 2.8 magnitude, appears only four percent illuminated and sets at 6:51 PM. Tuesday’s Moon is brighter at minus 5.4 magnitude, is about 10 percent illuminated and sets at 8 PM.
Neptune, Uranus and asteroid 4Vesta remain in their usual spots. Magnitude 7.9 Neptune resides in Aquarius, however nearby Tuesday’s Moon may overwhelm Neptune with its brightness; Neptune sets about 8:38 PM. Uranus is further from the Moon and, at magnitude 5.8, is visible in Pisces.
Uranus sets at Midnight. Asteroid 4Vesta lies about eight-and-a-half degrees above the star Iota in Cetus, and sets after 11 PM. All three require finder charts from astronomy media.
By 10 PM, the sky changes shifts. Jupiter is just risen in Leo and Comet Catalina is closing in on the Big Dipper, which also just rose. Monday night, Catalina shines about magnitude six and is about six-and-a-half degrees above the horizon. Tuesday places it about nine degrees high. The comet is about 4 degrees from the star Lambda Bootis, and about six degrees below the star Alkaid, the last star in the Big Dipper’s handle.
Midnight finds Jupiter moderately high in the eastern sky. While binocular users can see the planet and Galilean moons, telescopic observers can see the Great Red Spot (a giant storm) at 2:26 AM on Tuesday. They can also witness the Jovian moon Io being eclipsed by the planet at 1:29 AM.
Also on Tuesday, Io’s shadow begins to cross the planet’s face at 10:50 PM, followed by the moon itself at 11:54 PM; the shadow exits Jupiter at 1:05 AM Wednesday, followed by the planet itself at 2:08.
Jupiter continues to lead the planetary parade. Red planet Mars shines at first magnitude near the star Kappa in Virgo. Saturn rises at 4:32 AM, and is about ten degrees above the horizon at Astronomical Dawn. While the zero magnitude planet is binocular visible, it takes a telescope to fully perceive the beauty of its ring system. Venus shares Ophiuchus, rising at 4:50 AM about four degrees below Saturn. At minus four magnitude, Venus is certainly visible to the naked eye, but telescopes reveal it about 80 percent illuminated.