2020, December 1-7: Jupiter Closes Gap on Saturn

Jupiter closes in on Saturn as a prelude to the December 21, 2020 Great Conjunction.  During the week look for them in the southwest after sunset.  Jupiter is the brightest star in the region.  Saturn is to the Jovian Giant’s upper left. Jupiter sets around 7:30 p.m. CST, about 3 hours after sunset for other locations.

by Jeffrey L. Hunt

As the Great Conjunction of 2020 approaches, Jupiter and Saturn are visible in the southwest after sunset during early December.

Jupiter reduces the separation between the planets in the sky by about 0.5°, about the apparent diameter of the full moon.

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.

The planets are slowly moving eastward in Sagittarius, in front of several dim stars.

Jupiter is slowly over taking Saturn.

Jupiter sets around 7:30 p.m. CST, about 3 hours after sunset.  Check your local sunset time and look for the pair of planets beginning about 45 minutes after sundown until they are very low in the west, about 2 hours after sunset.

Here are the charts for the week:

December 1, 2020

Jupiter and Saturn in Sagittarius, December 1, 2020.
2020, December 1: One hour after sunset, Jupiter is 19° up in the southwest, 2.1° to the lower right of Saturn. In the starfield, Jupiter is 2.1° to the lower left of 56 Sagittarii (56 Sgr), while Saturn is 3.7° to the upper left of that star. Additionally, Saturn is 4.5° to the lower right of Sigma Capricorni (σ Cap, m = 5.2).

December 2, 2020

Jupiter and Saturn, December 2, 2020
2020, December 2: One hour after sunset, Jupiter is 19.0° up in the south-southwest. Dimmer Saturn is 2.0° to the upper left of the Jovian Giant. In the starfield, Jupiter is 2.3° to the lower left of 56 Sagittarii (56 Sgr), and Saturn is 3.8° to the upper left of the star. Additionally, Saturn is 4.4° to the lower right of Sigma Capricorni (σ Cap).

Jupiter and Saturn, December 3, 2020
2020, December 3: One hour after sunset, Saturn is 20.0° up in the south-southwest. Dimmer Saturn is 1.9° to the upper left of the Jovian Giant. In the starfield, Jupiter is 2.4° to the lower left of 56 Sagittarii (56 Sgr), and Saturn is 3.9° to the upper left of the star. Additionally, Saturn is 4.3° to the lower right of Sigma Capricorni (σ Cap).

December 4, 2020

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).

December 5, 2020

Jupiter and Saturn, December 5, 2020
2020, December 5: Jupiter and Saturn are low in the southwest as the sky darkens after sunset. Saturn is 1.7° to the upper left of Jupiter. Among the stars, Jupiter is 2.7° to the left of the star, while Saturn is 4.0° to the upper left of 56 Sagittarii (56 Sgr). Additionally, Saturn is 4.1° to the lower right of Sigma Capricorni (σ Cap).

December 6, 2020

Jupiter and Saturn, December 6, 2020
2020, December 6: One hour after sunset, Saturn is nearly 19° in altitude above the southwest horizon, 1.6° to the upper left of Jupiter. Saturn is 4.1° to the upper left of 56 Sagittarii (56 Sgr), while Jupiter is 2.8° to the lower left of the star. Saturn is approaching Sigma Capricorni (σ Cap). This gap is 4.0°.

December 7, 2020

Jupiter and Saturn, December 7, 2020
2020, December 7: Jupiter – over 17° up in the southwest – is 3.0° to the left of 56 Sagittarii (56 Sgr). Saturn is 4.2° to the upper left of that star and 3.9° to the lower right of Sigma Capricorni (σ Cap).
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.



Categories: Astronomy, Sky Watching

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