Planets visible to the naked eye
From September 6 to 20, 2021
Mercury is undergoing a very poor apparition in the evening sky until September 15: use binoculars to look for the tiny planet very low in the west 20 minutes after sunset. Mercury is gradually becoming fainter and harder to see with each passing evening during this period. Mercury will be passing between Earth and the Sun (inferior conjunction) on October 9, and will reappear in the morning sky a few days later.
Venus is the bright Evening Star that shines low in the west-southwest, 20 minutes after sunset; Venus itself sets about 80 minutes after the Sun. On the evening of September 9, the thin crescent moon hangs 4 degrees to the upper right of the Evening Star.
Mars is now too close to the Sun and is not visible. The Red Planet passes behind the Sun (conjunction) on October 8, and will reappear gradually in the morning sky in late November.
Jupiter was at opposition on August 19. The Giant Planet appears in the east-southeast at dusk. Around 11 p.m., it shines brightly about 30 degrees high in the south, and vanishes below the west-southwest horizon before 4 a.m. During the night of September 17 to 18, the waxing gibbous Moon comes within 5 degrees below Jupiter.
Saturn was at opposition during the night of August 1 to 2. The Ringed Planet appears at dusk above the east-southeast horizon, culminates around 10 p.m., 25 degrees high in the south and about 17 degrees to the right of very bright Jupiter, and sets before 3 a.m. in the west-southwest. During the night of September 16 to 17, the waxing gibbous Moon comes within 5 degrees below Saturn.