2024, June 30: Saturn Retrogrades

June 30, 2024: Saturn begins to retrograde, appear to move westward against the stars.  Jupiter, Mars, Moon, and Saturn are visible before sunrise.

Saturn through the Hubble Space Telescope
Photo Caption – A Hubble View of Saturn (NASA)

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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. Times are calculated by the US Naval Observatory’s MICA computer program.

Saturn Retrogrades, 2024

Saturn Retrogrades
Chart Caption – 2024, June 30: Saturn appears to move westward against the stars until November 15th.

Saturn’s retrograde begins.  This motion is an illusion as Earth overtakes the outer planet. This morning Saturn is nearly 865 million miles from Earth.  It appears against Aquarius’ distant starfield.

As our planet overtakes Saturn, passing between it and the sun, the line of sight – that normally appears to move eastward against the starfield (see the line marked A on the diagram) – shifts westward. 

This morning the planet is 109° west of the sun.

As Earth passes between Saturn and the central star, the two are separated by 180°, known as opposition (Line B).  This occurs September 7th this year.

Passing Saturn and moving ahead, the line of sight continues shifting westward until the Ringed Wonder appears 109° east of the sun on November 15th (Line C). Afterward, the line of sight shifts eastward again and the planet appears to be moving eastward against the distant stars.

In total, Saturn retrogrades nearly 7° westward.  That is less than the distance from pinky finger knuckle to thumb knuckle of an extended fist.

Binocular View

Saturn retrogrades, 2024
Chart Caption – 2024: Saturn retrogrades through a single binocular field of view in front of Aquarius during 2024.

The planet’s retrograde occurs against a faint Aquarius starfield within a single binocular field of view.  On the accompanying chart, several stars are labeled with either the Greek letter designation or numerically, and the constellation’s abbreviation, Aqr.

The planet passes between Phi Aquarii (φ Aqr) and Chi Aquarii (χ Aqr) during late August.  It passes 83 Aquarii (83 Aqr) during late September.  Look for the planet’s place in front of the star every week.

Here is today’s planet forecast:

Morning Sky

Saturn in Morning Sky

2024, June 30: One hour before daybreak, Saturn is in the south-southeast, above Deneb Kaitos and Fomalhaut.
Chart Caption – 2024, June 30: One hour before daybreak, Saturn is in the south-southeast, above Deneb Kaitos and Fomalhaut.

As Saturn’s retrograde begins, the Ringed Wonder is less than halfway up in the south-southeast at one hour before sunrise.  It is the brightest starlike body in the region.  Through a telescope, the planet’s rings and larger moons are visible.  The stars Fomalhaut and Deneb Kaitos are below the planet.

Jupiter, Mars, and Moon

2024, June 30: During morning twilight, Jupiter, Mars, and the moon are in the eastern sky.
Chart Caption – 2024, June 30: During morning twilight, Jupiter, Mars, and the moon are in the eastern sky.

Jupiter, Mars, and the moon are lined up in the eastern sky, to Saturn’s lower left.  The crescent moon, 33% illuminated, is over 30° above the east-southeast horizon. The lunar slice is still bright enough to cast shadows at this hour. Starting tomorrow, look for earthshine on the moon’s night portion, between the lunar cusps or horns.

Mars, marching eastward in front of Aries, is nearly 17° to the moon’s lower left and over 13° below Hamal, Aries’ brightest star.  Mars’ next planet conjunction occurs with Jupiter on August 14th.  This morning, the Red Planet is over 20° to Jupiter’s upper left.

Bright Jupiter is over 10° above the east-northeast horizon and 5.2° to Aldebaran’s upper left.  They fit into the same binocular field.  Aldebaran’s heliacal rising occurs when it is high enough to see without the binocular’s optical assist.

Evening Sky

Mercury, Challenging View

2024, June 30: Use a binocular to find Mercury low in the west-northwest at 30 minutes after sundown.
Chart Caption – 2024, June 30: Use a binocular to find Mercury low in the west-northwest at 30 minutes after sundown.

For those wanting an observing challenge, look for Mercury.  It is bright, but fades as it separates from the sun.  Thirty minutes after nightfall, locate a clear horizon looking west-northwest and use a binocular.  Appearing as a star, the elusive planet is over 5° above the horizon.

During the next few weeks, the planet is slightly higher in the sky each night, but dimmer.

Venus is east of the sun, but it sets about the time of Mercury’s sighting.

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