December 11, 2020: The Great Conjunction countdown: 10 days! Jupiter and Saturn are low in the southwest as night falls. Jupiter continues to close the gap to the Ringed Wonder. Farther eastward, Mars marches eastward in Pisces.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 7:09 a.m. CST; Sunset, 4:20 p.m. CST. Check local sources for sunrise and sunset times for your location.
As the sky darkens this evening after sunset, bright Jupiter is less that one-third of the way up in the southwestern sky. Dimmer Saturn is 1.0° to the upper left of the brighter planet. Both worlds are brighter than all the stars in the region.
The Great Conjunction of Jupiter and Saturn is 10 days away!
Jupiter seems on a slow final approach to meet Saturn, just east of the Sagittarius-Capricornus border. Watch Jupiter close the final gap by making nightly observations or make your own photographic record. Some ideas to photograph the planets, along with examples, are found here.
Be sure to see the planet pair early in the evening. Jupiter sets a few minutes after 7 p.m. CST, less than 3 hours after sunset. The best viewing time is 45 minutes after sunset for the next 75 minutes before the planets disappear behind neighborhood trees, houses, and buildings.
Meanwhile, bright, rusty Mars is about halfway up in the sky above the southeast horizon. It is in front of the dim stars of Pisces that make a background for its eastward motion as it revolves around the sun.
Mars is in the sky for a long period. It is south after 7:30 p.m. CST, about 3 hours after local sunset. It sets in the west a few minutes after 2 a.m. CST tomorrow morning, about 5 hours before local sunrise. (Check sunrise and sunset times for your location to determine the events described here.)
Mars is near the stars Zeta Piscium (ζ Psc on the chart) and Epsilon Piscium (ε Psc). Use a binocular to locate them near the Red Planet.
Read about Mars during December.
Detailed note: In the evening, Saturn is nearly 17° up in the southwest, 1.0° to the upper left of bright Jupiter. The Jovian Giant continues to close the gap to Saturn. Great Conjunction Countdown: 10 days. The Jupiter- Saturn gaps until the conjunction: Dec. 12, 0.9°, Dec. 13, 0.8°; Dec. 14, 0.7°; Dec. 15, 0.6°, Saturn moves into Capricornus; Dec. 16, 0.5°; Dec. 17, 0.4°; Dec. 18, 0.3°, Jupiter moves into Capricornus; Dec. 19, 0.2°; Dec. 20, 0.1°, Jupiter below Saturn. Farther eastward, Mars – nearly halfway up in the southeast – is 0.6° to the upper right of ζ Psc and 2.1° to the lower left of ε Psc. Use a binocular to observe Mars in front of the starry background.
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.
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