2021, May 23: Planet Parade Marches On


May 23, 2021:  Five bright planets parade across the sky.  Jupiter and Saturn are visible before sunrise in the southeastern sky.  The star Fomalhaut is becoming visible below bright Jupiter and near the horizon.   After sundown, Evening Star Venus, Mercury, and Mars are in the western sky.  The bright moon is in the southeastern sky during the nighttime hours.

Chart Caption – 2021, May 23: An hour before sunrise, bright Jupiter and Saturn are in the southeastern sky. The star Fomalhaut is below Jupiter and near the horizon.

by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:23 a.m. CDT; Sunset, 8:12 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

Morning Sky

Bright morning planets, Jupiter and Saturn, shine from the southeastern sky before sunup.

Saturn, brighter than most of the stars this morning, is about one-third of the way up in the south-southeast.  It is retrograding in Capricornus.

Retrograde motion is an illusion as our faster moving Earth is nearing its passage between the sun and the distant planet.

Jupiter, brighter than all the stars in the sky this morning, is nearly 18° to the lower left of Saturn.  It is moving eastward among the dim stars of Aquarius.  The constellation is famous, but its stars are faint, especially for most city dwellers.

You may have already noticed the star below Jupiter and about 5° above the horizon.  This is Fomalhaut, known as “the mouth of the southern fish.” It is the brightest star in Piscis Austrinus, the Southern Fish.  The star is 17th brightest visible from the skies of Earth.  The star is bluish-white, hotter than our sun.  It is about 25 light years away, shining with the intensity of over 30 stars the brightness of our sun.

Today, the sun’s appearance interrupts the planet parade separating it into a morning section with Jupiter and Saturn.  The evening section with Venus, Mercury, and Mars appears in the western sky after sundown.

Evening Sky

Chart Caption – 2021, May 23: Through a binocular, spot Mercury 5.7° to the upper left of Evening Star Venus.

Venus is easy to locate. Find it about 7° above the west-northwest horizon, 30 minutes after sunset.  Use a binocular to locate Mercury, dimming each evening, 5.0° to the upper left of Venus.

Venus as an evening star article.

Read more about Venus in our summary document.

Chart Caption – 2021, May 23: Forty-five minutes after sunset, Venus, Mercury, and Mars are visible in the western sky.

By 45 minutes after sunset, Venus is still above the horizon.  By this time Mercury is visible to the unaided eye.  Mars is 25° to the upper left of Mercury, beneath Castor and Pollux.

About a week ago, Mercury was bright and at its greatest separation from the sun. The planet is shifting back toward a close conjunction with Venus and to inferior conjunction.  It moves into the morning sky for an appearance during brighter twilight.

Here’s more about Mercury during May 2021.

Chart Caption – 2021, May 23: This evening the bright moon is 7.6° to the left of Spica.

The moon is visible in the southeast at sundown.  As the sky darkens, notice that the lunar orb is 7.6° to the left of Spica.

Here’s more about Mars during 2021.

Find a detailed chart of the motion of Mars during the month here.

Venus sets 76 minutes after sunset, followed by Mercury about 25 minutes later.  Mars sets 3 hours, 30 minutes after sunset.  Saturn begins tomorrow’s parade, when it rises about 70 minutes after Mars sets.

Detailed Note: One hour before sunrise, Saturn – nearly 28° up in the south-southeast – is retrograding slowly in Capricornus.  It is 0.6° to the right of the star θ Cap.  Jupiter, moving eastward in Aquarius – is 17.5° to the lower left of the Ringed Wonder.  You may have already noticed Fomalhaut (α PsA, m = 1.2) below bright Jupiter and near the horizon.  The star is over 5° above the southeast horizon.  Use a binocular to note that Jupiter is 2.3° to the upper left of ι Aqr, 4.3° to the lower right of θ Aqr, and 4.6° to the upper right of σ Aqr. The moon and three planets are visible after sunset.  Thirty minutes after sundown the bright lunar orb (12.3d, 92%) is over one-third of the way up in the southeast.  Brilliant Venus is over 7° above the west-northwest horizon.  In this bright twilight, use a binocular to spot Mercury (m = 1.3), 5.0° to the upper left of Venus.  Fifteen minutes later, Mercury is visible to the unaided eye, below the Bull’s horns, 3.9° to the lower left of Elnath.  At this time, Venus is about 5° above the horizon.  Mars – less than halfway up in the west – is over 25° to the upper left of Mercury. In the eastern sky, the moon is 7.6° to the left of Spica. One hour after sunset, Venus is over 2° above the horizon, while Mercury is nearly 9° up in the west-northwest.  Mars is 1.5° to the upper right of δ Gem and 7.0° to the lower left of Pollux.

 Read more about the planets during May 2021.

2021 – 2022, Venus – Mars Triple Conjunction

During 2021 into 2022, Venus passes Mars three times for a triple conjunction.  The first occurs on July 12, 2021.  The others occur during early 2022, followed by a close approach of the two planets.

2021, July 6: Venus – Saturn Opposition

July 6, 2021:  This is the second bright planet – planet opposition this month.  Venus and Saturn are in opposite directions from Earth.  Venus sets about the time that Saturn rises.  After this date, Venus and Saturn together are in the evening sky until early 2022.

2021, June 26 – June 30: Bright Moon, Morning Planets

June 26 – June 30, 2021:  The bright gibbous moon passes Jupiter and Saturn in the morning sky before sunrise.  Observe that the moon is in a different spot each morning, farther east toward the impending sunrise.

2021, June 15: Moon, Sickle of Leo

June 15, 2021:  The moon is with the Sickle of Leo this evening.  Step outside about an hour after sunset to find the crescent moon that is about 30% illuminated over one-third of the way up in the west.

Categories: Astronomy, Sky Watching

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