by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:53 a.m. CST; Sunset, 4:23 p.m. CST. Check local sources for sunrise and sunset times. Times are calculated by the US Naval Observatory’s MICA computer program.
At Chicago’s latitude, daylight lasts nine hours, thirty minutes, twenty-two minutes shy of the shortest daylight length that occurs on December 21st. The earliest sunset in Chicago, 4:20 p.m., begins on December 2nd and lasts through the 15th.
Summaries of Current Sky Events
Summary for Venus as a Morning Star, 2023-24
Here is today’s planet forecast:
This morning, the bright gibbous moon, 99% illuminated, rests on the western horizon one hour before sunrise. The Full (Beaver) moon phase occurs tomorrow morning at 3:26 a.m. CST.
Farther eastward at this hour, brilliant Venus shines in the southeastern sky, 5.6° to the upper left of Spica, Virgo’s brightest star. Venus passes in a wide conjunction in three mornings. The star Zubenelgenubi, the Scorpion’s southern claw, over 5° above the east-southeast horizon, is over 25° to the lower left of Venus. Their conjunction occurs on December 17th. After the Spica conjunction, watch Venus step eastward toward the claw.
Earlier this morning, about three hours before sunrise, Jupiter is low in the west, below the moon, while Venus is above the horizon in the east-southeast. The gap between the planets is nearly 165° and they are becoming difficult to see at the same time. This view of the morning sky with Venus and Jupiter bracketing the bright stars in the Orion region has been a delightful sight. What is the last morning you see them together? In two weeks, Jupiter sets as Venus rises, a planet-to-planet opposition. Afterward, Jupiter is below the horizon before Venus appears.
Mars, hiding in bright sunlight, rises only ten minutes before the sun. It is slowly climbing into the eastern morning sky.
Mercury seems to struggle to climb into the western evening sky. Its visibility suffers from a poorly inclined ecliptic, the plane of the solar system, for sky watchers at the mid-northern latitudes. Observers in the southern hemisphere have a dandy view of the planet.
This evening, Mercury is nearly 10° above the southwestern horizon at sunset, but it is lower in the sky as twilight fades, disappearing into the haze and blurring effects of the atmosphere. At forty-five minutes after sundown, it is only a few degrees above the horizon, setting fifteen minutes later.
The bright nearly-full moon is in the sky all night. An hour after sundown, the lunar orb is about 15° up in the east-northeast, over 20° to the lower left of bright Jupiter.
Jupiter, retrograding in front of Aries, is noticeably west of an imaginary line from Hamal, Aries’ brightest star, to Menkar. Outside the same binocular field of view with Jupiter, Hamal is 11.3° to the upper left of the planet, while Menkar is 13.3° below the distant world. Jupiter’s retrograde continues through the end of the year.
The moon is near the Pleiades star cluster, and both easily fit into the same binocular field. It is 1.9° to the lower right of Alcyone, the cluster’s brightest star. Through the binocular, the moon’s brightness can create a temporary afterimage, like that from a camera flash.
Saturn, remarkably dimmer than Jupiter, is over 35° up in the south. The Ringed Wonder is slowly moving eastward compared to dim Aquarius, washed out by the bright moonlight. Through a binocular, spot Deneb Algedi, 7.1° to the lower right of the planet. This is a tight fit. As Saturn picks up eastern speed, the gap becomes too wide for them to fit in the same field of view together.
During the night, Saturn, Jupiter, and the moon appear farther westward from Earth’s rotation. Saturn sets in the west-southwest over six hours after nightfall and before midnight. Jupiter is south about an hour before Saturn sets and appears in the western sky as Venus rises tomorrow morning. The moon’s place is over ninety minutes behind Jupiter. It is visible in the western sky after its all-night passage across the sky.
- 2023, December 19: A Scorpion Fumble, Moon MidwayDecember 19, 2023: Before sunrise, Venus appears below the Scorpion’s claws. After sundown, the moon is nearly midway from Saturn to Jupiter.
- 2023, December 18: Pinched VenusDecember 18, 2023: Look for Venus between the Scorpion’s claws in the southeast before sunrise. The thick crescent moon is in the evening sky with Jupiter and Saturn.
- 2023, December 17: Celestial PairsDecember 17, 2023: Before sunrise, Venus passes Zubenelgenubi, a planet-star conjunction. After sundown, Saturn and crescent moon are paired, a planet-moon conjunction.
- 2023, December 16: Venus Clawed, Evening Crescent Nears SaturnDecember 16, 2023: Before daybreak, Venus is above the Scorpion’s southern claw. After nightfall, the crescent moon nears Saturn.
- 2023, December 15: Brilliant Morning Star, Evening Lunar CrescentDecember 15, 2023: Before sunrise, brilliant Venus approaches Zubenelgenubi, the Scorpion’s southern claw. The crescent moon returns to the western evening sky.