April 16, 2021: Mars and the crescent moon are in the west after sunset. Taurus is the starry drop for the planet and the lunar slice. Use a binocular to see Mars and the crescent moon in the same field of view.
by Jeffrey L. Hunt
Chicago, Illinois: Sunrise, 6:08 a.m. CDT; Sunset, 7:33 p.m. CDT. Check local sources for sunrise and sunset times for your location.
In a few evenings, Venus makes its first evening appearance without the aid of a binocular or telescope. This evening the planet sets 26 minutes after sunset.
One hour after sunset, the crescent moon, 20% illuminated, is less than halfway up in the west. Mars is 5.6° to the upper left of the lunar slice.
Mars is above the Bull’s horns – Elnath and Zeta Tauri (ζ Tau on the chart) – and far above the “V” of Taurus that is made by Aldebaran and the Hyades star cluster.
The moon is 5.3° to the lower right of Zeta Tauri and 5.4° to the lower left of Elnath.
Use a binocular to spot the moon and Mars with dimmer background stars. Even with a wide-field binocular, it is not possible to fit the crescent moon, Mars, Elnath, and Zeta Tauri in the field of view simultaneously, only three at a time. The gap between Elnath and Zeta Tauri is too large to fit both of them in the field of view at the same time.
Here’s more about Mars during 2021.
Read about Mars during April.
Detailed Note: One hour before sunrise, Jupiter is 12.0° up in the east-southeast, 2.9° to the upper left of Deneb Algiedi. Jupiter is 0.1° to the right of μ Cap. Use a low power telescopic eyepiece to observe the plane of Jupiter’s moons below the star. Europa is to the lower right of the star, while Callisto is less than 0.1° to the lower left of the star. Saturn – 13.6° to the upper right of Jupiter – is nearly 17° up in the southeast. The Ringed Wonder is 1.7° to the upper right of θ Cap. One hour after sunset, the crescent moon (5.0d, 20%) is less than one-half of the way up in the west, 5.6° to the lower right of Mars. The lunar crescent is 5.3° to the lower right of ζ Tau, while Mars is 3.8° to the upper right of the star. With Elnath, the moon is 5.4° to the lower left, while Mars is 5.0° to the star’s upper left. With a wide-field binocular it’s possible to fit the moon, Mars and one of the horns of Taurus in the field of view, but not all four objects simultaneously. The gap between the horns is too large to fit into a binocular field.
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!