2023, July 21: Five Bright Planets


July 21, 2023:  Jupiter and Saturn are visible before sunrise. Brilliant Venus and the crescent moon are easy to see as night falls.  Use a binocular to Mercury and Mars.

Photo Caption – 2022, July 30: The crescent moon with earthshine. (Photo by MJB)


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:34 a.m. CDT; Sunset, 8:20 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

Chart Caption – 2023, July 21: Saturn is in the south-southwest during morning twilight.

Jupiter and Saturn are visible before sunrise.  At one hour before daybreak, begin in the southern sky with Saturn about 35° up in the south-southwest.  The planet is retrograding in front of Aquarius, 7.1° to the upper right of Skat, meaning “the leg,” and 5.7° to the lower right of Lambda Aquarii (λ Aqr on the chart).

The starfield is dim and washed out by the perpetual intrusion of outdoor lighting for sky watchers in urban and suburban settings.  Use a binocular to track Saturn compared to the stars.

Chart Caption – 2023, July 21: Jupiter is in the east-southeast before sunrise.

Bright Jupiter is nearly halfway up in the east-southeast, 12.0° below Hamal, Aries brightest star.  The planet is slowly moving eastward compared to the stellar background.  Notice that it is midway between Hamal and Menkar, Cetus’ nostril.

Evening Sky

Chart Caption – 2023, July 21: Venus, Mercury, Mars, crescent Moon, and Regulus are in the western sky.

The planet gathering that includes the moon is quickly breaking up in the western sky after sundown.  Look for the celestial bundle from a spot with an unobstructed view toward that horizon.

Begin looking for the crescent moon, 16% illuminated, as night falls, starting at thirty minutes after sundown.  The lunar orb is over 18° to the upper left of brilliant Venus.  The other three players, Mercury, Mars, and Regulus are dimmer and a binocular is needed to see them in the bright blush of evening twilight.  From Mercury to the lunar crescent, the bunch spans over 26°.

Mercury is 10.0° to the right of Venus, too far away to fit into the same binocular field.  The planet is bright, but too dim to be seen without the optical assist.

By forty-five minutes after sundown, Venus and Mercury are less than 5° above the horizon. The time window to see this gathering is narrow.

Chart Caption – 2023, July 21: Venus, Mars, and Regulus appear in overlapping binocular fields.

The star Regulus, Leo’s brightest, is 4.1° above Venus, while Mars is 7.0° to the upper left of the star. The accompanying chart shows overlapping binocular fields to locate Venus, Regulus, and Mars.  This is the last evening Mars and Regulus fit into the same field of view.

Venus reverses its direction and begins to retrograde tomorrow.  The planet’s closest approach to Regulus was 3.5° on the 16th.  Venus and Regulus had a near or quasi-conjunction.  The Evening Star did not pass the planet.  The conjunction of the pair does not occur until October after they move to the morning sky.

Venus and Mercury set sixty-five minutes after sunset and Mars follows about forty-five minutes later.

Photo Caption – 2023, May 22: Brilliant Venus and the crescent moon, with earthshine,

The moon displays earthshine, reflected sunlight from Earth’s oceans, clouds, and land.  The effect is easily visible to the unaided eye and amplified through a binocular.  Capture it with a tripod-mounted camera and an exposure up to a few seconds.

Chart Caption – 2023, July 21: Three hours after sunset, Saturn is in the east-southeast.

Saturn rises about two hours after sundown.  An hour later, it is nearly 15° up in the east-southeast. During the night it appears farther west.  By morning twilight, it is in the south-southwest.



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