2023, July 1:  Mercury at Superior Conjunction, Brilliant Venus


July 1, 2023: Mercury begins an evening appearance with superior conjunction at the sun.  Brilliant Venus is in an interval of greatest brightness after sundown.

Photo Caption: 2021, May 13: The crescent moon is 3.2° to the upper left of Mercury.


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:19 a.m. CDT; Sunset, 8:30 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.

The new month opens with fifteen hours, eleven minutes of daylight.  During July sunshine loses forty-four minutes.

Chart Caption – 2023, July 1: Mercury is at superior conjunction.

Mercury is at superior conjunction after midnight in the Central Time zone.  This event separates the morning appearance of the planet with the evening apparition.  Through convention means, the planet is not visible because it is in the sky with the sun.

Revolving around the sun every eighty-eight days, Mercury catches and passes Earth every 116 days.  When the speedy planet moves between Earth and the sun, this is known as inferior conjunction.  When the planet is on the far side of the sun with the central star in the center of the alignment, this is known as superior conjunction, today’s event.

Mercury moves into the evening sky during twilight. Later during the month, Mercury joins Venus, Mars, Moon, and Regulus in the west after sundown.

Summaries of Current Sky Events


Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, July 1: During morning twilight, Saturn is in the southern sky above Fomalhaut and to the upper left of Deneb Algedi.

Jupiter and Saturn are visible before sunrise.  Saturn is higher and appears toward the south.  One hour before daybreak, the Ringed Wonder is less than halfway up in the sky.  While not as bright as Venus and Jupiter, the planet is outshined by only a few stars this morning.

Saturn is to the upper right of Fomalhaut – “the mouth of the southern fish” – that is about half way from the horizon to the planet and over 13° to the upper left of Deneb Algedi – “the kid’s tail” – in Capricornus.

Saturn appears to move westward against the starry background from our planet catching and moving between Saturn and the sun.  This retrograde motion is an illusion as we overtake Saturn.

Chart Caption – 2023, July 1: Before sunrise, Jupiter is in the east below Hamal.

Bright Jupiter is over 25° up in the east and 11.1° to the lower right of Hamal, Aries’ brightest star.  The Jovian Giant is gently moving eastward compared to the distant stars.

Notice other brighter stars in the same region of the sky.  This includes Menkar, “the sea monster’s nostril,” to Jupiter’s lower right and the Pleiades star cluster over 20° to Jupiter’s lower left.  Aldebaran, Taurus’ brightest star is near the horizon in the east-northeast.

Evening Sky

Chart Caption – 2023, July 1: Venus, Mars, and Regulus are in the west after sundown.

Brilliant Venus, in its interval of greatest brightness, sparkles in the western sky as night falls. While the planet is the brightest starlike body, it varies in brightness, and the change is easily noticed across several weeks.

An hour after sundown, the Evening Star is less than 15° above the horizon.  The planet’s eastward trek is stalling as Mars, 3.6° to the upper left, marches away toward a conjunction with Regulus on the 10th that is 5.2° beyond the Red Planet. Venus does not pass Regulus, but closes the gap to the star to 3.5° on the 16th.

Regulus is slightly north of the solar system’s plane.  Venus crosses the plane on the 3rd, heading southward.  While Mars is moving parallel to the ecliptic, Venus is moving at an angle away from the plane and Regulus.

Venus’ eastward motion ends on the 22nd, 4.2° from Regulus.  It then begins to retrograde and rapidly overtakes Earth on an orbital path closer to the sun.

Through a telescope, Venus, featureless from its blanket of clouds, shows a crescent phase 32% illuminated.

Chart Caption – 2023, July 1: The moon is above Scorpius, to the lower left of Antares and above the tail and stinger, the Cat’s Eyes.

Farther eastward this evening the bright moon, 97% illuminated, is about 15° up in the south-southeast, 11.3° to the lower left of Antares and above the Scorpion’s tail and stinger, sometimes called the Cat’s Eyes.  The Full (Buck) moon occurs July 3rd at 6:39 a.m. CDT.

The bright moon washes out the dimmer stars across in the sky and especially in its immediate vicinity.



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