2021, May 12: Spectacular Venus-Moon Grouping

May 12, 2021: Evening Star Venus and the crescent moon make a spectacular grouping after sunset. Thirty minutes after sunset, the razor-thin moon is 1.2° to the left of brilliant Venus.  This is the closest grouping of the moon and Venus during this evening appearance of the brilliant planet.  Mercury is 9.1° to the upper left of Venus.  Mars maintains its eastward march in Gemini. Sirius and Aldebaran are near their heliacal settings, their final appearances in the evening sky for the year.

2021, May 12: The moon is 1.2 degrees to the left of brilliant Venus.
2021, May 12: The moon is 1.2 degrees to the left of brilliant Venus.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:33 a.m. CDT; Sunset, 8:01 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

This evening the planet parade continues after sunset.  This morning Jupiter and Saturn led the pack with their visibilities in the southeast before sunrise.

After sunset this evening, brilliant Venus is over 5° up in the west-northwest.  The razor-thin crescent moon, only 1% illuminated, is 1.2° to the left of the planet.

Use a binocular to initially locate the pair.

This is the closest grouping of Venus and the moon during this appearance of the planet in the evening sky.

Likely, the best view of Venus and the moon occurs on December 6 when the crescent moon appears 3.2° below the brilliant planet.  This occurs in a darker sky and the planet is at its brightest.

This evening when the Venus – moon pair is low in the sky, Mercury is over 9° to the upper left of Venus.

Venus as an evening star article.

Read more about Venus in our summary document.

2021, May 12: Forty-five minutes after sunset, the Venus – Moon pair, Mercury, and Mars are visible in the western sky.
Chart Caption – 2021, May 12: Forty-five minutes after sunset, the Venus – Moon pair, Mercury, and Mars are visible in the western sky.

By 45 minutes after sunset, the planet – moon pairing is near the horizon, while Mercury stands nearly 9° up in the sky. 

Mercury is nearing greatest separation from the sun as it makes its best evening appearance of the year.  As the planet continues to appear higher in the sky each evening, its brightness dims.  It is brighter than most stars, and at this time interval after sunset, it is easily visible without an optical assist of a binocular.

Dimmer Mars is to the upper left of Mercury and Venus.

Sirius and Aldebaran are nearing their last appearances in the evening sky for the year – their heliacal settings. Sirius is very low in the west-southwest. Aldebaran in evening charts, near Venus and the moon this evening.

Here’s more about Mercury during May 2021.

2021, May 12: One hour after sunset, Mars is in the west, below Castor and Pollux, 1.8° to the upper left of Epsilon Geminorum (ε Gem) and 4.8° to the right of Zeta Geminorum (ζ Gem).
Chart Caption – 2021, May 12: One hour after sunset, Mars is in the west, below Castor and Pollux, 1.8° to the upper left of Epsilon Geminorum (ε Gem) and 4.8° to the right of Zeta Geminorum (ζ Gem).

An hour after sunset, Mars – about one-third of the way up in the west – is in front of the stars of Gemini, below Castor and Pollux.  It continues its eastward march through Gemini.  This evening it is 1.8° to the upper left of Epsilon Geminorum (ε Gem on the chart), Mebsuta, “the outstretched paw of the lion,” and 4.8° to the right of Zeta Geminorum (ζ Gem), Mekbuda, “the folded paw of the lion.”

Here’s more about Mars during 2021.

Detailed Note: One hour before sunrise, bright Jupiter is 21.0° up in the southeast.  It is 1.5° to the upper left of ι Aqr.  Saturn – over 24° up in the south-southeast – is 16.4° to the upper right of Jupiter. Saturn is 0.7° to the right of θ Cap.  Three planets are on display after sunset.  Thirty minutes after sundown, brilliant Venus is over 5° up in the west-northwest.  Use a binocular to locate the razor thin moon (1.3d, 1%) 1.2° to the left of Venus.  This is the closest pairing of Venus and the moon during this evening apparition of the planet.  Fifteen minutes later, the Venus – moon pair is still about 3° above the horizon.  Mercury (m = −0.1) is 9.1° to the upper left of Venus.  One hour after sunset, Mercury is nearly 9° above the west-northwest horizon with Mars over 28° to its upper left.  In the starfield Mars is 1.8° to the upper left of ε Gem and 4.8° to the right of ζ Gem.

Read more about the planets during May 2021.



Categories: Astronomy, Sky Watching

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