Skywatch Line for Monday and Tuesday December 11th and 12th, 2023
This is the Skywatch Line for Monday and Tuesday December 11th and 12th, written by Joe Slomka.
The Sun sets at 4:21 PM; night falls at 6:03. Dawn breaks at 5:34 AM and ends with sunrise at 7:17.
Monday’s Moon is located in western Scorpius, diameter is 31 arc-seconds, only 1% illuminated, rises at 5:57 AM and sets at 3:03 PM. Tuesday’s Moon shifts to western Ophiuchus, slightly larger and sets at 3:47 PM; it is officially “New” at 3:47 PM. These moons set so early they are not visible at night. Weather permitting, it will be a great time for observation.
Monday, asteroid 4Vesta lies in Gemini at 9 PM, near the foot of Pollux, 6th magnitude, a tiny .4 arc-seconds, 99% lit and 38° high. It rose at 5:20 PM, highest at 12:46 AM and sets at 8:07 AM. Easy to spot with binoculars, the Minor Planet is in retrograde, which means that it travels backwards (westward); it is also one of the larger Minor Planets and in Opposition on December 21st.
Most of the planets rise during daylight; Venus is the only exception. Mars is still too close to the Sun. Mercury is the first visible planet, in southwest Sagittarius, shines with zero magnitude, 8 arc-seconds, 36% lit, 4° high at 5 PM and sets at 5:30 PM.
Saturn is next, in Southern Aquarius, gleaming with 9th magnitude, 16 arc-seconds, 34° highest at 4:50 PM and sets at 10:02 PM. Neptune follows 23° behind Saturn, glistens with 8th magnitude, 2 arc-seconds, 44° highest at 6:16 PM and sets at 12:07 AM.
Jupiter and Uranus share Aries. Jupiter draws attention, glimmering with minus 2nd magnitude, a large 46 arc-seconds, 42° at 6 PM, 59° highest at 8:50 PM and sets at 3:49 AM. Jupiter, as usual, has treats for the sky watcher. Tuesday, at 2:07 AM, the Moon Io begins to cross the planet’s face, followed by its shadow at 3:04 and ends at 5:14 AM. Ganymede and Europa begin a series of crossings beginning at 6:51 PM and ending with Europa at 12:51 AM on Wednesday. The Great Red Spot begins its trek at 2:27 AM also on Wednesday. Uranus is found 13° behind Jupiter, gleaming with 5th magnitude, 3 arc-seconds, 36° high at 6 PM, 64° highest at 10:42 PM and sets at 4:52 AM.
Venus in southeastern Libra, rises at 3:44 AM, blazes with minus 4th magnitude, 15 arc-seconds, 28° at 7 AM, 71% lit and setting at 2 PM.
Winters in the Northeast are notoriously cloudy. However, when skies are clear, the night sky presents a riot of brilliant stars and constellations that seem close enough to reach out and touch. In fact, twenty-three of the fifty brightest stars are visible in tonight’s sky. Orion, the Dogs and Taurus account for the majority of the brightest stars in the heavens. Sirius is not only brightest on this list, but also second only to the Sun in luminosity; it is also the leading light of Canis Major, the Large Dog. About half of the list lies relatively close to us; the other half is intrinsically brighter, though further away. So, if it is clear, bundle up and enjoy Nature’s sky show.
Clear Skies Joe Slomka