2023, December 8:  Morning Moon-Spica Conjunction, Three Bright Planets

Venus, Mercury, Spica, and Moon, November 13, 2020
Photo Caption – 2020, November 13: Sparkling Venus – nearly 18° up in the east-southeast – is 8.1° to the upper right of the old moon and 5.5° to the upper left of Spica. The lunar crescent is 6.9° to the lower left of Spica and 5.1° above Mercury.


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 7:05 a.m. CST; Sunset, 4:20 p.m. CST.  Check local sources for sunrise and sunset times. Times are calculated by the US Naval Observatory’s MICA computer program.

Summaries of Current Sky Events
Summary for Venus as a Morning Star, 2023-24

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, December 8-9: Brilliant Venus is in the southeast before sunrise. The crescent moon moves eastward, passing Spica and the Morning Star.

In two mornings, Venus and Jupiter reach their planet-to-planet opposition.  They are 180° apart in the sky as Jupiter sets when Venus rises.  The window to see them together is only twenty minutes long, beginning three hours, thirty-five minutes before daybreak. Venus is above the horizon in the east-southeast while Jupiter is in the west-northwest. Set an early alarm.  They are in the sky at the same time again after sundown during late 2024.

This morning, an hour before sunrise, the crescent moon, 20% illuminated, is over 30° above the horizon and 2.3° to the upper left of Spica, Virgo’s brightest star.  This is a lovely sight.

Each month, the moon passes Spica and until the April 2024 Full Moon, the lunar phase phase is larger.  A bright moon near Spica is a sure celestial signal that spring has returned in the northern hemisphere.

Photo Caption – 2022, September 23: Crescent moon with earthshine.

This morning, look for earthshine on the moon between the lunar cusps or horns.  The soft illumination is from sunlight reflecting from Earth’s oceans, clouds, and land.  This effect is easily visible to the unassisted eye, but a binocular improves the view.  Photograph the scene with a tripod-mounted camera and exposures up to a few seconds.

This morning brilliant Venus is 12.1° to the lower left of the moon.  Venus continues to step eastward toward Zubenelgenubi, the Scorpion’s northern claw, 11.2° to the planet’s lower left.  Venus passed Spica over ten days ago and overtakes the claw in a week.

Mars is slowly climbing into the eastern morning sky.  This morning it rises less than thirty minutes before the sun and is lost in the central star’s brilliance.

Evening Sky

Chart Caption – 2023, December 8: Mercury is low in the southwest during bright evening twilight.

A few days after greatest elongation, speedy Mercury is a challenging view in the southwest during evening twilight.  At sunset, the planet is over 10° above the southwest horizon. Thirty minutes later it is over 5° in altitude.  Find an observing spot with a clear horizon in that direction and use a binocular.  The planet is easier to see at forty-five minutes after sunset, but the planet is less than 5° up in the sky.  Be persistent.  This is a challenging view that may take multiple attempts during this brief window of time.

Chart Caption – 2023, December 8: After nightfall, Saturn is in the south.

An hour after nightfall, Saturn is about 35° up in the south.  The planet is not bright like Venus or Jupiter, but it is easy to identify.  The star Fomalhaut, representing the mouth of the Southern Fish, is slightly dimmer than the Ringed Wonder and nearly 20° to the lower left.

From urban and suburban areas, a binocular is needed to see the background stars.  Saturn is plodding eastward in front of dim Aquarius, 10.4° to the lower right of Lambda Aquarii (λ Aqr on the chart), 10.1° to the upper right of Skat, the Aquarian’s leg, and 7.7° to the upper left of Deneb Algedi, Capricornus’ tail.

Chart Caption – 2023, December 8: Bright Jupiter is in the east-southeast after sunset.

Bright Jupiter is over 30° above the east-southeast horizon at this hour.  The planet is slowly retrograding in front of Aries, 11.4° to the lower right of Hamal, meaning “the full-grown lamb,” and 13.9° to the upper right of Menkar, meaning “the nostril.”  A binocular is helpful to see these stars as well, especially Menkar.

Photo Caption – Jupiter (NASA Photo)

At 10:04 p.m. CST, Jupiter’s Great Red Spot is visible through a telescope at the planet’s center in the southern hemisphere.

Saturn is farther westward during the night, setting in the west-southwest less than six hours after sunset.  Jupiter is south an hour before Saturn sets.  With the Venus-Jupiter opposition imminent, the window to see the two planets is only thirteen minutes long beginning three hours, thirty-three minutes before sunrise.

Tomorrow a wonderous Venus-Moon conjunction occurs.  Look toward the east-southeast about an hour before sunrise. 


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