April 28, 2021: Evening Star Venus and bright Mercury are low in the west-northwest during bright evening twilight. Later during the evening, Mars is at the feet of Gemini. Use a binocular to spot the star cluster Messier 35 below the Red Planet. Near midnight, the moon is in the southeast near Antares.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 5:51 a.m. CDT; Sunset, 7:46 p.m. CDT. Check local sources for sunrise and sunset times for your location.
Brilliant Venus continues its slow entry into the evening sky and Mercury is at the beginning of its best evening appearance of the year.
The window to see Venus and Mercury is narrow and now occurs during bright twilight. During May, both planets are visible in a darker sky, although Mercury is dimmer.
This evening, use a binocular to spot brilliant Venus about 20 minutes after sunset, low in the west-northwest. Bright Mercury is in the same binocular field of view as Venus. It is 3.0° above Venus. Can you see them without optical aid?
Read more about Venus in our summary document.
As the sky darkens and stars become visible, after Venus and Mercury set in the west-northwest, Mars is nearly 40° up in the west at the feet of Gemini. It is 2.3° to the right of Propus, “the projecting foot” (η Gem on the chart) and 3.1° to the lower right of Tejat Posterior, “the heel” (μ Gem).
Use a binocular to spot the distant cluster of stars cataloged as Messier 35 (M35). Mars is 1.3° above the cluster.
The moon is low in the southeast about 4 hours after sunset, near midnight. The lunar orb, over 90% illuminated, is 4.2° to the upper left of Antares, “the rival of Mars.”
Here’s more about Mars during 2021.
Read about Mars during April.
Detailed Note: One hour before sunrise, the moon (16.3d, 98%) is nearly 18° up in the southwest. The lunar orb is 7.2° to the right of Dschubba (“the forehead,” δ Sco, m = 2.3). Farther eastward, Jupiter is over 16° above the southeast horizon. In the starfield, it is 4.5° to the left of Deneb Algiedi, 1.8° to the lower left of μ Cap, and 1.7° to the upper right of ι Aqr. Saturn is 14.9° to the upper right of Jupiter. In the starfield, the Ringed Wonder is 1.1° to the upper right of θ Cap. Twenty minutes after sunset, Venus is nearly 3.8° above the west-northwest horizon. Mercury (m = −1.3) is 3.0° above Venus. Have you observed them without a binocular? Mercury continues to dim as its nightly altitude increases. An hour after sunset, Mars is less than 40° up in the west in front of the stars of Gemini. It is 2.3° to the upper right of Propus and 3.1° to the lower right of Tejat Posterior. Use a binocular to observe the star cluster M35, 1.3° below the Red Planet. As midnight approaches, the moon (17.0d, 93%) – 13.0° up in the southeast – is 4.2° to the upper left of Antares (α Sco, m = 1.0).
Read more about the planets during April 2021.
November 7, 2021: During the early evening Venus and the moon group together in the southwest.
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.