2023, August 8: Wonderous Jupiter-Moon Conjunction, See Jupiter’s Moons, Uranus


August 8, 2023: Bright Jupiter and the Moon are visible during the morning before daybreak.  Jupiter’s moons and planet Uranus are visible through a binocular.

Photo Caption – Jupiter greets the moon during morning twilight.


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:50 a.m. CDT; Sunset, 8:01 p.m. CDT.  Check local sources for sunrise and sunset times. Today is the last day the sun sets after 8 p.m. CDT in Chicago. 

Sunset over the ocean

Sunset does not return to a post 8 p.m. time until May 11, 2024.

In this 30 second exposure, a meteor streaks across the sky during the annual Perseid meteor shower Friday, Aug. 12, 2016 in Spruce Knob, West Virginia. Photo Credit: (NASA/Bill Ingalls)

The Perseid meteor shower peaks before twilight begins on the morning of the 13th.  Brighter meteors related to the shower can be seen during the next several mornings, but the bright moonlight overwhelms the dimmer shooting stars. The moon is waning and the overhead scene is darker each morning for the dimmer meteors. For night owls or early risers, stand under a darker celestial vault and look upwards for a bright Perseid or two, although meteors from the shower can be seen anywhere up there. By the peak morning the moon phase is a waning crescent, not interfering much with the shower. The meteor rate decreases slowly after the 13th.

Summaries of Current Sky Events

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, August 8: Jupiter and the moon appear together in the eastern sky before daybreak.

Bright Jupiter and the moon are together from their first appearance in the eastern sky about midnight until Jupiter disappears into morning dawn.  One hour before sunrise, the Last Quarter moon is high in the southeast, 2.5° to the upper left of bright Jupiter. It is a pretty sight in the blush of morning twilight.

Jupiter is slowly moving eastward in front of Aries, 12.9° to the lower left of Hamal, the constellation’s brightest star.

Chart Caption – 2023, August 8: An overlapping binocular view of Jupiter, Moon, and Uranus as twilight begins.

An hour earlier, about the beginning of twilight, Uranus is visible through a binocular to the lower left of Jupiter and the moon.  First place the Jovian Giant and the moon in the center of the field of view.  Locate Jupiter’s four large moons, known as the Galilean satellites, from Galileo’s first observations of them. Ganymede and Io are east of the planet, while Europa and Callisto are to the west. Hold the binocular steadily.

Planet Uranus is not visible in the same field of view with Jupiter and the moon, but about one binocular field away.  When viewing the moon, move the binocular slightly to the lower left.  The stars Zeta Arietis (ζ Ari on the chart) and Delta Arietis (δ Ari) are over 2.5° above the planet.  Aim the binocular so those two stars are at the upper left of the view.  Uranus is near the center, appearing as a pale blue-green star. 

Uranus is at the limit of eyesight when viewed in a dark location, away from the perpetual intrusion of outdoor lighting.  It is distinctly dimmer than the two stars. The accompanying chart shows two overlapping binocular fields. 

Diagram Caption – A movie maker’s view of what a binocular sees Free public domain CC0 image.

Contrary to the portrayal of a binocular field in the movies, a binocular makes both eyes look at the same view.  So the chart represents two separate views that overlap, not the movie maker’s take on the scene viewed through the binocular.

Follow the moon westward during the day.  It sets in the west during the early afternoon, about six hours before sunset. Next month, the phase is a waning gibbous when it passes Jupiter as the planet appears farther westward during the next 30 days.

Chart Caption – 2023, August 8: Saturn is in the east-southeast two hours after nightfall.

Dimmer Saturn, is less than 30° above the southwest horizon at this hour. Dimmer than might be expected, it is brighter than most of the stars in the sky this morning. Find the star Fomalhaut, the mouth of the Southern Fish, over 10° above the south-southwest horizon and nearly 20° to the lower left of Saturn.

The Ringed Wonder is approaching opposition, when Earth is between the planet and the sun, on the night of the 26th/27th.  While the planet is over 800 million miles away from Earth on this night, it is closest and a spectacular sight through a telescope. Saturn seems to move westward compared to the starry background from our planet overtaking the distant world. This is an illusion.  Saturn continues to move eastward through its orbital path, but backwards against the stars.  The planet is in front of Aquarius’ dim stars.  Use a binocular to see the starfield.

Evening Sky

Photo Caption – This picture of Venus was taken by the Galileo spacecraft (NASA)

Venus nears inferior conjunction, between Earth and the sun, on the 13th and an appearance in the morning sky.

Mercury nears its greatest elongation – largest separation from the sun – on the 9th. The planet dims each night.  This evening, 30 minutes after sundown, the speedy planet is about 5° above the west-northwest horizon.  It is faint and a binocular may help with its identification, but it is likely washed out by the bright glow of evening twilight. Sky watchers south of the equator see Mercury in its best evening appearance of the year.  It is higher in the sky during evening twilight.

These side-by-side images of Mars, taken roughly two years apart, show very different views of the same hemisphere of Mars. Both were captured when Mars was near opposition, which occurs about every two years, when Earth’s orbit catches up to Mars’ orbit. At that time, the Sun, Earth, and Mars fall in a straight line, with Mars and the Sun on “opposing” sides of Earth. (NASA Photo)

Mars is very dim and wiped out by twilight.  Its complete disappearance is slow, passing behind the sun during November.  It reappears in the morning sky during early 2024.

Chart Caption – 2023, August 8: Saturn is in the east-southeast two hours after nightfall.

As Saturn nears opposition it rises closer to the sunset time, forty-nine minutes after sundown tonight.  Over an hour later, the planet is over 15° above the east-southeast horizon. Jupiter rises over three and one-half hours after sundown, and nearly three hours after Saturn.  The moon rises after midnight and less than an hour behind Jupiter. 

Tomorrow morning find the thick crescent moon with the Pleiades star cluster before sunrise.



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