2020, December 22: Jupiter, Saturn Great Conjunction, The Evening After

2020, December 22: Jupiter and Saturn are low in the southwest after sunset.

December 22, 2020:  Jupiter inches away from Saturn as the gap between the planets grows slightly.  The gibbous moon and Red Planet Mars are on the southeast after sunset.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 7:16 a.m. CST; Sunset, 4:24 p.m. CST.  Check local sources for sunrise and sunset times for your location.

As the sky darkens, Jupiter and Saturn are still close together in the southwest.  Jupiter is to the upper left of Saturn.  The gap is slightly larger than last night.  On following nights, the gap continues to grow.  The two planets will not be this close together again until 2080 – three great conjunctions away.

You can see the planets easily in the southwest from about 45 minutes after sunset until about 90 minutes after sunset.  They set in the west over 2 hours after the sun disappears below the horizon.

2020, December 22: One hour after sunset, the gibbous moon is the lower right of bright Mars in the southeastern sky. Mars is 3.6° to the left of Zeta Piscium (ζ Psc) and 3.7° to the lower right of Pi Piscium (π Psc).

Farther eastward, the bright gibbous moon is to the lower right of Mars in the southeast.  The moon is over 60% illuminated.

Mars continues its eastward march in Pisces.  Use a binocular to find it about midway between Zeta Piscium (ζ Psc on the chart) and dim Pi Piscium (π Psc).

Mars is in the south about 3 hours after sunset. It sets in the west over 5 hours before sunrise.

Read about Mars during December.

Detailed note: Forty-five minutes after sunset, Jupiter and Saturn are less than 14° in altitude above the southwest horizon. The Jupiter – Saturn gap is 0.1° (602 arcseconds.)  Jupiter is to the left of Saturn. As the sky darkens further, the bright gibbous moon (8.3d, 60%) – about halfway up in the sky in the southeast is nearly 13° to the lower right of Mars.  Use a binocular to spot the starfield behind Mars.  The planet is nearly midway from ζ Psc to π Psc, but slightly below a line that connects them.  Mars is 3.6° to the left of ζ Psc and 3.7° to the lower right of π Psc.

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

Read more about the planets during December.


Leave a Reply Cancel reply