Skywatch Line for Friday, January 12, through Sunday, January 14, 2024 written by Sam Salem
This is Dudley Observatory’s Skywatch Line for Friday, January 12, through Sunday, January 14, written by Sam Salem.
On Friday, Sun rises at 7:25am and sets at 4:43pm; Moon rises at 8:45am and sets at 6:06pm.
If you have a low southwestern horizon and clear skies you might be able to spot the very thin waxing crescent Moon in bright twilight shortly after sunset on Friday. Saturn will be the steady golden light higher in the sky.
Early on Saturday and Sunday evenings, the thin waxing crescent Moon will pass Saturn. On Saturday, the waxing crescent Moon forms a long triangle with Saturn and Fomalhaut in late dusk. On Sunday, the Moon, Saturn, and Fomalhaut form a similar triangle to the one they did on Saturday, but mirror-reversed along the axis between the planet and star. Check out the unlit portion of the Moon. That glow you see is earthshine, which is light reflected from Earth.
The Moon will reach perigee, its closest point in its elliptical orbit around Earth, at 7am on Saturday, when it’s 225,102 miles away.
Mercury reaches greatest elongation, distance from the Sun, on Friday. Mercury shines low in the dawn this week to the lower left of bright Venus. Their separation shrinks slightly to 11° on Friday. Mercury remains about magnitude 0.0.
Venus, at magnitude –4.0, shines as the bright “Morning Star” in the southeast during dawn. It’s getting lower every week. Nearby is not just Mercury but also sparkly orange Antares, the brightest star in the zodiacal constellation of Scorpius. Look for Antares about 9° to Venus’s right.
Jupiter, at magnitude –2.5 in the constellation of Aries, is the bright white dot dominating the high south early these evenings. It stands at its highest soon after dark. In a telescope, it has shrunk to 42 arcseconds wide.
Saturn, at magnitude +1.0 in the constellation of Aquarius, is getting lower in the southwest during and after dusk. Saturn sets around 8 pm.
The Gemini twins lie on their sides these January evenings, left of Orion. Their head stars, Castor and Pollux, are farthest from Orion, one over the other. Castor is the top one. The feet of the Castor stick figure are just left of the top of Orion’s very dim Club.
The brightest asteroid in the sky, 4 Vesta, is just past opposition. Vesta will cruise about ½° south of the dim Crab Nebula, M1, on Friday and Saturday. Binoculars will show Vesta easily at magnitude 6.5. But you’ll need a fine-scale finder chart to tell it from all the other faint pinpoints in the area.