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.
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.
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.
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.
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.
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.
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!