2020, December 4: Morning Star Venus, Gibbous Moon, Evening Planet Dance

Moon, December 4, 2020
2020, December 4: One hour before sunrise, the bright gibbous moon to the upper left of the Gemini Twins.

In the morning sky brilliant Morning Star Venus waltzes through Libra near Zubenelgenubi in the east-southeast.  Venus is “that bright star” in the eastern sky before sunrise.  The bright gibbous moon shines near the Gemini Twins in the western sky.  In the evening sky, Mars – in the east-southeast – marches through Pisces. Jupiter closes the gap on Saturn as a prelude dance to the Great Conjunction, 17 evenings away.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 7:02 a.m. CST; Sunset, 4:20 p.m. CST.  Check local sources for sunrise and sunset times in your location. Add the time intervals in the notes to your local sunrise or sunset times.

Morning: The bright gibbous moon is high in the west-southwest about an hour before sunrise.  Its reflected sunlight easily casts shadows on the ground.  Stand outside for a few moments and as your eyes adjust, you’ll see your own shadow from the moon as well as the shadows of your surroundings.  Look carefully and you’ll see the Gemini Twins, Pollux and Castor, to the moon’s lower right.  You may have to block out the moon’s glare.  Simply use your hand as you would with the sun during a bright day.  Farther east, brilliant Venus blazes from low in the east-southeast.  It is 1.4° to the left of Zubenelgenubi.  Use a binocular to see the planet 1.6° to the lower left of Mu Librae (μ Lib on the chart).

Venus in Libra, December 4, 2020
2020, December 4: One hour before sunrise, brilliant Venus is 12.0° up in the east-southeast, 1.4° to the left of Zubenelgenubi and 1.6° to the lower left of Mu Librae (μ Lib).

Venus is getting lower each day at this time interval.  If you wait a little longer, Venus is higher in the sky.  The stars will be more difficult to see. A binocular is necessary to see them as twilight proceeds.

Venus, December 4, 2020
2020, December 4: Brilliant Venus is 1.4° to the left of Zubenelgenubi.

Morning detailed note: One hour before sunrise, the moon (19.3d, 85%) is 49.0° above the west-southwest horizon.  It is 6.7° to the upper left of Pollux. Farther east, brilliant Venus is 12.0° up in the east-southeast, 1.4° to the left of Zubenelgenubi and 1.6° to the lower left of μ Lib. 

See our summary about Venus during December 2020 and the feature article  about Venus as a Morning Star.

Mars in Pisces, December 4, 2020
2020, December 4: One hour after sunset, Mars is over 41° up in the east-southeast, between ε Psc and 80 Psc. The Red Planet is 1.0° to the lower right of Epsilon Piscium (ε Psc) and 1.6° to the upper right of 80 Piscium (80 Psc.)

Mars, December 4, 2020
2020, December 4: Mars is in the southeast after sunset. It is entering a tiny triangle of dim stars make by Zeta Piscium (ζ Psc), Epsilon Piscium (ε Psc), and 80 Piscium (80 Psc).

Evening: In the evening, Mars continues marching eastward among the stars of Pisces.  While dimmer than about two months ago when it was closest to Earth, it is the brightest “star” in the east.  Use a binocular to notice that the planet is between Epsilon Piscium (ε Psc on the chart) and 80 Psc.  When Zeta Piscium (ζ Psc) is added, the stars make a small nearly equilateral triangle.  Make nightly observations to spot Mars changing its position in that triangle.

Read about Mars during December.

Jupiter and Saturn, December 4, 2020
2020, December 4: One hour after sunset, Jupiter is 1.8° to the lower right of Saturn. Jupiter is 2.5° to the left of 56 Sagittarii (56 Sgr), while Saturn is 3.9° to the star’s upper left. Saturn is 4.2° to the lower right of Sigma Capricorni (σ Cap).

Jupiter and Saturn, December 4, 2020
2020, December 4: One hour after sunset, Jupiter is 1.8° to the lower right of Saturn.

One hour after sunset, Jupiter and Saturn are low in the west-southwest.  They are in eastern Sagittarius.  Jupiter is overtaking Saturn as the Great Conjunction of December 21, 2020 approaches.  Their separation this evening is 1.8° In the starfield a binocular is needed to watch the slow dance that the planets make with the stars and each other. This evening Jupiter is 2.5° to the left of 56 Sagittarii (56 Sgr on the chart).  Jupiter is 2.5° to the left of 56 Sgr while Saturn is 3.9° to its upper left.  Saturn is beginning to approach Sigma Capricorni (σ Cap).

Evening detailed note: One hour after sunset, Mars is over 41° up in the east-southeast, between ε Psc and 80 Psc. The Red Planet is 1.0° to the lower right of ε Psc and 1.6° to the upper right of 80 Psc.  Farther west, Jupiter is over 18° above the southwest horizon. The Jupiter – Saturn gap is 1.8°. Dimmer Saturn is to bright Jupiter’s upper left. Great Conjunction Countdown: 17 days. Among the stars, Jupiter is 2.5° to the left of 56 Sgr, while Saturn is 3.9° to the star’s upper left.  Additionally, Saturn is 4.2° to the lower right of σ Cap.  Six hours after sunset (10:20 p.m. CST), the moon (20.0d, 79%) is over 19° in altitude in the east.  It is in front of the dim stars of Cancer.

For more about the Great Conjunction, read our feature article. This is the closest Jupiter – Saturn conjunction since 1623.

Here is more about the planets during December 2020.

Moon in the Bull's Horns. October 8, 2020

2021, August 14: Waxing Moon, Stellar Double

August 14, 2021: This evening the waxing moon is near Zubenelgenubi, the southern claw, that is a stellar double.  Use a binocular to see both stars that are in a gravitation dance.

Moon and Venus, August 15, 2020

2021, August 13: Evening Sky, Bright Planets

August 13, 2021: This evening the crescent moon appears between Evening Star Venus and Spica as the lunar slice dances eastward.  Jupiter and Saturn are in the southeastern sky.

The crescent moon, November 19, 2020

2021, August 12: Evening Sky, Lunar Dance

August 12, 2021: This evening the crescent moon appears between Venus and Spica as the lunar slice dances eastward.

2021, May 13: The crescent moon is 3.2° to the upper left of Mercury.

2021, August 11: Waxing Moon, Evening Star

August 11, 2021:  The waxing crescent moon is to the upper left of Evening Star Venus this evening in the western sky.

The Crescent Moon, November 16, 2020

2021, August 10: Evening Star Venus, Crescent Moon

August 10, 2021:  The crescent moon is near Venus in the western sky after sunset.



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