2022, September 28: Seasonal Stars, Evening Crescent Moon


September 28, 2022: Three bright planets – Mars, Jupiter, and Saturn – are visible overnight.  Arcturus and Fomalhaut hint at the season.  The lunar crescent is near the Scorpion’s claws after sundown.

Chart Caption – Early Autumn: Arcturus and the Big Dipper are low in the western sky during early evening hours.


by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 6:45 a.m. CDT; Sunset, 6:37 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

As early autumn begins with earlier sunsets, the stars that are visible are shifting westward each evening.  The sky is noticeably different from week to week.

This evening when stepping outside to note the planets’ places, look for Arcturus and the Big Dipper in the western sky.  Their starting positions indicate that the autumn season is here.  Each year about this time, topaz Arcturus is less than one-third of the way up in the west during the early evening.  It is part of the constellation Boötes, the Bear Chaser.

The Big Dipper is part of the larger pattern Ursa Major, the Great Bear.  The seven brighter stars of the pattern are likely the first pattern that children learn in North America.  The shape is to the right of Boötes.

Arcturus is the second brightest star visible from the mid-northern latitudes and the brightest north of the celestial equator – the imaginary line in the sky above Earth’s (imaginary) equator. The star is nearly 40 light years away and shines with an intrinsic brightness of about 100 suns.

The star makes its first evening appearance during March, but during autumn, the star is far enough north to be seen in the west after sunset and in the east before sunrise. 

Before sunrise, the Big Dipper is standing on its handle in the northeastern sky, but Arcturus is not yet in the sky as September’s end nears.  When spotting Mars in the morning, attempt to find Arcturus during the next few weeks.

Fomalhaut – the mouth of the southern fish – is another sign of autumn.  It is beginning to show on the evening charts, but it is not yet identified on the evening diagrams showing Jupiter and Saturn.  At the beginning of October, the star will be identified.  It is low in the east-southeast about two hours after sundown.

In The Friendly Stars, Martin and Menzel describe Fomalhaut’s seasonal appearance.  “There is a calm dignity about this star that lends much interest to it.  It comes gently into view far down in the southeast in August, but with so little of a flourish that one scarcely notes its presence until along in early September. Then, when the days are growing shorter, some evening, just after dark, one sees it, a conspicuous, impressive object serenely trailing along over the small arc of its circle in the south with no companion near it, and, apparently, no need of one to add to its splendor” (p. 45).

Fomalhaut is the thirteenth brightest star seen in the northern sky, about the same intensity as Gemini’s Pollux.

Here is today’s planet forecast:

Morning Sky

Chart Caption – 2022, September 28: Before daybreak, Jupiter is low in the west.


An hour before sunrise, bright Jupiter is low in the western sky.  A few days after its opposition with the sun, it is lower in the sky each morning, soon to be below the horizon at this time interval.

The Jovian Giant is retrograding in front of Pisces’ dim stars.  This illusion of westward motion continues until late November.

Chart Caption – 2022, September 28: During morning twilight, Mars is in the south, approaching the Bull’s horns.

Mars continues to brighten as it marches eastward in Taurus. Only Jupiter and Sirius are brighter than the Red Planet at this hour.


Mars is approaching the Bull’s horns – Elnath and Zeta Tauri – splitting the gap between them on October 17th. It appears in the same binocular field of view with Zeta this morning. Mars does not appear in the same field of view with the horns because they are too far apart to fit.

Venus continues its slide into bright twilight and its superior conjunction with the sun later next month.  The Morning Star rises 34 minutes before sunrise.  It is tough to find in the east 20 minutes later.  At the same time Jupiter is very low in the west.  In three mornings, Venus rises after Jupiter sets, although Earth’s nearest planet is bathed in bright twilight.  By then it is washed by brighter light and nearly impossible to find with the approaching dawn.

Mercury is emerging from  bright sunlight for its best morning appearance of the year.  For a few days around October 8, the planet shines from low in the eastern sky.  This morning it rises 47 minutes before sun.  It is too dim to see this morning.

Evening Sky

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

About 45 minutes after sundown the crescent moon, 10% illuminated, is low in the west-southwest, 2.0° to the lower right of Zubenelgenubi, the Scorpion’s southern claw. The crescent is over 30° to the lower left of bright Arcturus that was described in the introduction section of today’s article and podcast.

The moon is showing earthshine, reflected sunlight from Earth’s oceans, clouds, and land.  The accompanying photograph of the lunar crescent was made by a ten-year-old.  The photographer was amazed at the ease of capturing the earthshine effect, even without a tripod to steady the camera.

Chart Caption – 2022, September 28: After sundown, Jupiter and Saturn are in the eastern sky.

At this hour, Saturn is less than one-third of the way up in the southeast to the right (west) of Deneb Algedi and Nashira in eastern Capricornus.  The Ringed Wonder is retrograding toward Iota Capricorni (ι Cap) that can be seen from regions that do not suffer from the glare of outdoor lighting.  Others need a binocular to see the planet 1.1° to the left of the star.

Chart Caption – 2022, September 28: Through a binocular, Saturn is approaching Iota Capricorni (ι Cap).

Through a telescope Saturn’s icy ring system is easily visible.  The large moon Titan is east of the planet, visible at low telescopic powers.  It is one of five large moons that can be seen, seemingly zig-zagging about the planet.

Saturn leads the planet parade westward.  Mars is rising before midnight and during the early morning hours, it is strung along an arc westward through Jupiter to Saturn.  Pegasus and Andromeda, with the closest galactic system, are above Jupiter.  Saturn sets nearly four hours before sunrise.  By early twilight Jupiter and Mars are again visible.  The Big Dipper is on its handle in the northeast.  What is the first day you can see Arcturus before sunrise?  Follow the curve of the dipper’s handle.  It’s pointing below the horizon.  The star is nearing its first morning appearance, even though it’s still in the evening sky.



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