2023, August 28: Three Morning Planets, Moon Approaches Saturn

Photo Caption – 2020, July 17: The crescent moon, Brilliant Venus, and Aldebaran shine from the eastern during early morning twilight.


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:12 a.m. CDT; Sunset, 7:31 p.m. CDT.  Check local sources for sunrise and sunset times. Times are calculated by the US Naval Observatory’s MICA computer program.

The five-planet morning parade continues with Venus, Jupiter, and Saturn easily visible.  Uranus is easy to locate through a binocular between Jupiter and the Pleiades star cluster.  The challenging view, even through a binocular, is locating Neptune in a dim Pisces starfield, over 20° to the upper left of Saturn.  For sky watchers interested in seeing the two more distant planets, see the directions in the August 27th article.

 Summaries of Current Sky Events

Summary for Venus as a Morning Star, 2023-24

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2023, August 27: Venus and Sirius are in the eastern sky before daybreak.

As the new calendar day opens, the gibbous moon, 87% illuminated, is low in the west-southwest.  Farther eastward, Saturn is over one-third of the way up in the south-southeast.  Bright Jupiter is about 20° up in the east.

As the new morning proceeds, the moon sets as the wheel of the sky spins westward.

By an hour before daybreak, brilliant Venus is over 5° above the eastern horizon.  It continues to zip into the morning sky, gaining seven minutes of rising time each morning compared to sunrise.

Notice Sirius, the night’s brightest star, 10° up in the east-southeast, over 40° to the upper right of Venus.  The planet is about fifteen times brighter than the star. Beginning about September 10, Venus and Sirius are about the same altitude – height above the horizon – for several mornings.

Procyon, above an imaginary line from Venus to Sirius, is about 15° up in the east.  Rising about 25 minutes before Sirius, Procyon, known as the “Little Dog Star,” means “before the dog,” for its earlier rising time interval before Sirius.

Chart Caption – 2023, August 28: During morning twilight, Jupiter is high in the south.

Bright Jupiter is high in the south at this hour.  It is slowly moving eastward in front of Aries, 13.5° to the lower left of Hamal, the constellation’s brightest star, and nearly 16° to the lower right of the Pleiades star cluster, part of Taurus.

The Jovian Giant’s eastward gait slows to start the illusion of retrograde on September 4th.  Earth is beginning to overtake the solar system’s largest planet, passing between the sun and the planet on November 3rd.

Chart Caption – 2023, August 28: Through a telescope, the star Sigma Arietis (σ Ari) is west of Jupiter and its largest, brightest satellites.

Through a telescope of 80x magnification, Jupiter’s globe is easy to see as well as some salmon-painted clouds that are whipped parallel to the planet’s equator.  Jupiter’s four largest moons, known as the Galilean satellites, appear as stars in the same plane as the planet’s equator.  This morning Ganymede and Europa are east of the planet, while Io and Callisto are west.  Callisto is near the farthest we see it from Jupiter’s globe.

The star Sigma Arietis (σ Ari on the chart) is farther west from Callisto in the telescopic eyepiece.  The moon and the star can be seen through a binocular if held steadily.  Sigma seems to have been imitating a Jovian moon, but it has served as a distant stellar landmark as Jupiter moved past it on the sky.

Chart Caption – 2023, August 28: Before sunup, Saturn is the west-southwest.

The third bright planet is Saturn.  Find it about 10° up in the west-southwest at this hour. The Ringed Wonder is retrograding in front of Aquarius, 8.4° to the lower right of Skat, the Aquarian’s leg, and 8.2° to the lower right of Lambda Aquarii (λ Aqr on the chart).  The planet and the stars nearly make an equilateral triangle.

From Venus to Saturn, the three bright planets span over 157° from east to west-southwest.  Trace an imaginary arc from the Morning Star to the Ringed Wonder through Jupiter. (Yes, point at the sky and trace the arc through the three planets.) This is the plane of the solar system, where the planets and moon appear against the background stars, known as the ecliptic.  A wider band, 9° on either side of that arc, is the zodiac or circle of animals.

Evening Sky

Photo Caption – Mercury as Never Seen Before. (NASA photo)

While still in the evening sky, Mercury and Mars are hidden by the sun’s bright light.  The inner-most planet sets only twelve minutes after the sun.  It passes between Earth and the central star, known as inferior conjunction, on September 6th and hops into the morning sky.  It joins Venus, Jupiter, and Saturn about a week later, making four bright planets and two dim ones available for morning viewing.

Photo Caption – 2007, December 1: Late winter in the northern hemisphere shows clouds above the northern polar cap and some above the southern cap. (NASA Photo)

Mars is on a very slow slide into brighter twilight.  It sets about an hour after sundown, but is dimmer than might be expected.  So, it is awash in bright evening twilight.

Chart Caption – 2023, August 28: After sundown, the nearly-full moon and Saturn are in the southeastern sky.

At one hour after sunset, Saturn, rising before the sun sets, is over 10° above the east-southeast horizon and less than 30° to the lower left of the gibbous moon, 94% illuminated, that is 15° up in the southeast.

The next Full moon occurs in two evenings at 8:36 p.m. CDT, the second one this month.  Since it does not have a seasonal name like Harvest or Hunter’s, the name “Blue Moon” is used. The term Sturgeon Moon was used for August’s seasonal name.  The next name in the seasonal sequence is Harvest because of its association with agricultural activity.  It is traditionally, the Full moon closest to the autumnal equinox.  This year’s Harvest Moon occurs September 29th.

Jupiter rises nearly three hours after sundown and is visible in the eastern sky as midnight approaches.


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