2023, May 31: Morning Planets, Brilliant Evening Star


May 31, 2023: Jupiter and Saturn are visible before sunrise.  Venus shines brightly from the western sky until about midnight.

Photo Caption – A close approach of Venus and Mars, yet no conjunction. Mars outside the limits of Venus maximum separation from the sun.


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:19 a.m. CDT; Sunset, 8:18 p.m. CDT.  Check local sources for sunrise and sunset times for your location.  Times are calculated by the U.S. Naval Observatory’s MICA computer program.

Summaries of Current Sky Events


Here is today’s planet forecast:

Morning Sky

Jupiter and Saturn are in the eastern sky before sunrise.  With twilight occurring longer during late spring, the two giant planets are visible one hour before daybreak.  While Saturn is dimmer than Jupiter, the Ringed Wonder is higher in the sky.  Look for it nearly 30° above the southeast horizon, one-third of the way from the horizon to overhead.  It is nearly 20° to the upper left of the star Fomalhaut, meaning “the mouth of the southern fish.”

Meanwhile, bright Jupiter is about 10° above the eastern horizon, likely behind a terrestrial obstacle.  Look for it from a hilltop or elevated structure to see beyond the visual clutter.

Chart Caption – 2023, May 31: Use a binocular to spot Mercury to the lower left of Jupiter.

Mercury is racing into the morning sky, although this morning appearance has poor visibility.  At thirty minutes before sunup, in bright twilight, the speedy planet is about 5° above the east-northeast horizon and over 12° to the lower left of Jupiter.  This is a binocular only appearance for the planet.  Mercury and Jupiter are too far apart to fit into the same binocular field of view.  As with Jupiter locate an unobstructed view toward the horizon.

Here at month’s end some news reports are calling for a view of five planets – Mercury, Jupiter, Saturn, Uranus, and Neptune.  Six are in the sky if classic planet Pluto is included.  Neptune rises about an hour before daybreak and when it is high enough to be visible, the dimmest planet in the solar system’s modern model is awash in morning twilight.  Uranus is not far from Mercury and is about one hundred times dimmer.  Pluto rises around midnight and it can be found through larger telescopes.  In reality, Jupiter and Saturn are visible without optical help, while a binocular is needed for Mercury.  The other three are impossible views.

Evening Sky

Chart Caption – 2023, May 31: The moon is near Spica after sundown.

One hour after sunset, the gibbous moon, 89% illuminated, is over 30° above the south-southeast horizon and 7.8° to the lower left of Spica, Virgo’s brightest star, meaning “the ear of corn.”  The Full moon occurs in three days.

Chart Caption – Venus moves in front of Gemini, May 7-June 2, 2023.

Brilliant Venus continues its display in the western sky.  Quite simply it is “that bright star in the west.”  From Chicago and other locations in the eastern regions of their time zones, the planet sets before midnight and later for sky watchers in the western areas of their time dividers.

Chart Caption – 2023, May 31: Venus and Mars are in the western sky after sundown.

The planet is stepping eastward in front of Gemini, 4.6° to the lower left of Pollux, one of the Gemini Twins. During the next two evenings, watch the Evening Star approach and cross and imaginary line that begins at Castor, the other Twin, and extends through Pollux.  This shows the planet’s quick eastward rate.

Venus is closing a gap to Mars.  This evening the separation is 10.9°.

Chart Caption – 2023, May 31: Through a binocular, Mars is near the Beehive star cluster.

Mars, about Castor’s brightness, is marching eastward in front of Cancer’s dim stars.  Through a binocular, Mars appears 1.1° to the lower right of the Beehive star cluster.  Watch Mars march toward and step into the cluster.

This western planet dance is easy to observe.  Take a look each clear evening.



Leave a Reply Cancel reply