JUPITER
The solar system's largest planet opens 2021 still near Saturn as a low evening star. By mid-January, it's just too low to see. In late February, it emerges as a very bright predawn morning star. After this, it rises 2 hours earlier each month. It's up before midnight beginning in late June and visible all night when it comes to opposition on the night of August 19–20. It's well placed for viewing through the rest of the year but solely as an evening star after Thanksgiving.
Jan. 1 set 6:05 A
Jan. 11 set 5:37 B
Jan. 21 set 5:10 B
Feb. 1 rise 6:54 E
Feb. 11 rise 6:22 E
Feb. 21 rise 5:49 E
Mar. 1 rise 5:23 D
Mar. 11 rise 4:50 D
Mar. 21 rise 5:16 D
Apr. 1 rise 4:39 D
Apr. 11 rise 4:04 D
Apr. 21 rise 3:29 D
May 1 rise 2:54 D
May 11 rise 2:18 D
May 21 rise 1:42 D
June 1 rise 1:01 D
June 11 rise 12:23 D
June 21 rise 11:40 D
July 1 rise 11:00 D
July 11 rise 10:20 D
July 21 rise 9:39 D
Aug. 1 rise 8:53 D
Aug. 11 rise 8:11 D
Aug. 21 set 5:55 B
Sept. 1 set 5:05 B
Sept. 11 set 4:19 B
Sept. 21 set 3:35 B
Oct. 1 set 2:52 B
Oct. 11 set 2:11 B
Oct. 21 set 1:31 B
Nov. 1 set 12:50 B
Nov. 11 set 11:10 B
Nov. 21 set 10:36 B
Dec. 1 set 10:03 B
Dec. 11 set 9:31 B
Dec. 21 set 9:01 B
Dec. 31 set 8:31 B
SATURN
As the year begins, the Ringed Planet, in Capricornus, is still visible as a low evening star beneath much brighter Jupiter. By mid-January, it's immersed in evening twilight. In late February, it begins its predawn morning star apparition. Steadily higher up at dawn through winter into early spring, Saturn rises before midnight beginning in June. Its best 2021 viewing begins about a month before its August 2 opposition, when it's out all night. It remains an easy target for the rest of the year, becoming strictly an evening sky object in late autumn. Its stunning rings, moderately "open" (in view), require at least 30x magnification.
Jan. 1 set 5:59 B
Jan. 11 set 5:25 B
Jan. 21 set 4:52 B
Feb. 1 rise 6:39 E
Feb. 11 rise 6:03 E
Feb. 21 rise 5:28 E
Mar. 1 rise 4:59 E
Mar. 11 rise 4:23 E
Mar. 21 rise 4:46 E
Apr. 1 rise 4:06 E
Apr. 11 rise 3:28 E
Apr. 21 rise 2:51 E
May 1 rise 2:13 E
May 11 rise 1:34 E
May 21 rise 12:56 E
June 1 rise 12:12 E
June 11 rise 11:28 E
June 21 rise 10:48 E
July 1 rise 10:08 E
July 11 rise 9:27 E
July 21 rise 8:45 E
Aug. 1 rise 8:00 E
Aug. 11 set 5:04 B
Aug. 21 set 4:21 B
Sept. 1 set 3:35 B
Sept. 11 set 2:53 B
Sept. 21 set 2:11 B
Oct. 1 set 11:31 B
Oct. 11 set 12:52 B
Oct. 21 set 12:12 B
Nov. 1 set 11:27 B
Nov. 11 set 9:50 B
Nov. 21 set 9:13 B
Dec. 1 set 8:38 B
Dec. 11 set 8:03 B
Dec. 21 set 7:28 B
Dec. 31 set 6:55 B
MERCURY
The smallest planet is also the fastest, dashing around the Sun at 30 miles per second. For us to readily observe this world, it must be at least 5 degrees above the horizon 40 minutes after sunset or before sunrise, when its brightness exceeds magnitude 0.5. This year, such favorable conditions occur in twilight during the last 3 weeks of January and all of May. It's lower during September and the last 2 weeks of December. As a morning star, Mercury is best seen this year from the last half of March into early April, in mid-July, and in the first half of November.
DO NOT CONFUSE: • Mercury with Saturn during their predawn conjunction from February 18 to 26. Mercury is much brighter and slightly orange. • Mars and the famous Scorpius star Antares when they meet before dawn in the final 6 days of this year. Although they are the same orange color, Antares is brighter. • Venus with Mercury when they meet low in evening twilight from December 27 to 29. Although Mercury is quite bright, Venus is even more luminous.