April 23, 2021: Evening Star Venus and Mercury are entering the evening sky. They are found very low in the west-northwest after sunset. The bright moon is in the southeastern sky during the early evening. Mars is moving toward the star cluster Messier 35.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 5:58 a.m. CDT; Sunset, 7:41 p.m. CDT. Check local sources for sunrise and sunset times for your location.
Venus is slowly making its way into the evening sky. While still a challenging observation, try to spot the planet about 3° up in the west-northwest at 20 minutes after sunset. Try with a binocular to first locate it Venus, then look with optical help.
Mercury is entering the evening sky for its best evening appearance for the year. The planet is bright, 1.9° to the lower right of brilliant Venus.
To see these planets find a clear natural horizon. Viewing from a hillside or an elevated structure will help with the view.
Read more about Venus in our summary document.
The very bright, nearly full moon, 87% illuminated, is nearly 50° up in the southeast. The bright lunar orb is 7.5° to the lower right of Denebola, “the lion’s tail.” Too see the star, hold your hand up to block the moon’s glare – as you would to shield your eyes from the sun.
Because of the moon’s light, the dimmer stars are more difficult to see as well as the star cluster (Messier 35) that Mars is approaching in the feet of Gemini.
Find the Red Planet, one hour after sunset about halfway up in the west. It is 4.1° to the lower right of Propus (η Gem). The star cluster is 1.9° to the upper left of Mars. Use a binocular to view the cluster with Mars and Propus.
During the next few evenings, Mars moves closer to the star cluster, but the moon’s increasing brightness makes the view more challenging.
Here’s more about Mars during 2021.
Read about Mars during April.
Detailed Note: One hour before sunrise, Saturn is 19.0° up in the southeast, 1.3° to the upper right of Theta Capricorni (θ Cap). Jupiter is 14.4° to the lower left of the Ringed Wonder. In the starfield, Jupiter is 3.8° to the upper left of Dene Algiedi, 1.0° to the lower left of μ Cap and 2.2° to the upper right of ι Aqr. Twenty minutes after sunset, Venus is nearly 3° up in the west-northwest. Mercury (m = −1.8) – less than 2° in altitude – is 1.9° to the lower right of Venus. Find a clear horizon. As the sky darkens further, find Mars 39.0° up in the west, 1.8° to the right of 1 Geminorum (1 Gem, m = 4.2) and 4.1° to the lower right of Propus. Under bright moonlight use a binocular to spot the star cluster M35, 1.9° to the upper left of Mars. Farther eastward, the moon (12.0d, 87%) is nearly 50° up in the southeast. It is 7.5° to the lower right of Denebola (β Leo, m = 2.1).
Read more about the planets during April 2021.
November 6, 2021: The midpoint of Autumn occurs today.
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.
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.
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.
October 29 – November 1, 2021: The crescent moon moves in front of the stars of Leo in the eastern sky before sunrise. Watch the moon appear lower and the phase shrink (wane) each morning. Also note that there is no Full moon on Halloween this year!