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.
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.
2021, November 7: Venus, Moon Conjunction
November 7, 2021: During the early evening Venus and the moon group together in the southwest.
2021, November 6: Autumn’s Midpoint
November 6, 2021: The midpoint of Autumn occurs today.
2021, November 3: Unusual Mercury, Crescent Moon Spectacular
November 3, 2021: Before sunrise speedy planet Mercury, the crescent moon, and the star Spica are grouped together. The trio does not appear this close together again until 2033.
2021, October 31: NO Halloween Full Moon
October 31, 2021: There is no Halloween Full moon this year, and the phase is not close. The crescent moon is in the morning sky. Mercury is low in the east-southeast before sunrise. The planet pack – Venus, Saturn, and Jupiter – gleam in the evening sky.
2021, October 29: Venus, Greatest Elongation
October 29, 2021: Venus reaches its greatest elongation from the sun. It is in the evening sky with Jupiter and Saturn. The crescent moon and Mercury are in the eastern sky before sunrise.
Categories: Astronomy, Sky Watching
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