Astronomy Essentials

Visible planets and night sky for September

Posted by

Marcy Curran

and

John Jardine Goss

and

Deborah Byrd

and

Kelly Kizer Whitt

and

September 20, 2023

September 20 and 21 evenings: Moon and Antares

The thick waxing crescent moon will pass the bright red star Antares, Heart of the Scorpion in the constellation Scorpius on the evenings of September 20 and 21. The moon will pass in front of, or occult, Antares at around 8 UTC (3 a.m. CDT) on September 21, 2023, from these locations: Japan, eastern Russia, Guam and Northern Mariana Islands. Details on the occultation here.

White dots for the moon on 2 days and the constellation Scorpius, with a red dot for Antares, plus a green ecliptic line. — Chart via EarthSky.

Comet Nishimura, now in the evening sky

Comet C/2023 P1 (Nishimura) has now moved from the morning sky to the evening sky. Early sightings were promising, but we haven’t heard much about it lately, or seen many photos. The comet is in bright twilight! Read more about Comet Nishimura.

Chart showing comet in the evening. — View larger. | Comet Nishimura in the evening sky, September 10-21, via Stuart Atkinson. Used with permission. For a view of the comet from your location, try Stellarium.org.

EarthSky Minute for September 18-24

Late September, into early October: Venus and Mercury

Venus reaches greatest brilliancy on September 19. And Mercury – near its September 22 greatest elongation – will be nearby. The video below has more.

September 22, evening: 1st quarter moon

The instant of first quarter moon falls at 19:32 UTC (2:32 p.m. CDT) on September 22.

September 22 and 23 evenings: Moon near Teapot

The first quarter moon will move in front of the Teapot – an asterism – in the constellation Sagittarius the Archer on the evenings of September 22 and 23, 2023. The Teapot marks the direction to the center of our Milky Way galaxy.

White dots for the moon on 2 days plus the Teapot connected by lines and a green ecliptic line. — Chart via EarthSky.

September 23: Equinox

The September equinox – when the sun crosses the celestial equator, moving from north to south – happens at 6:50 UTC (1:50 a.m. CDT) on September 23. This equinox brings autumn to the Northern Hemisphere, and spring to the Southern Hemisphere. Read about the 2023 September equinox, or watch the video below.

September and October: Watch for the zodiacal light

The weeks around the September equinox are the best time to see a hazy pyramid of light in the sunrise (Northern Hemisphere) or sunset (Southern Hemisphere) direction. Watch for this light – called the zodiacal light – before dawn breaks, or when all traces of evening twilight have left the sky. Read more here, or watch the video below.

September 24 and 25 evenings: Moon visits Capricornus

The bright waxing gibbous moon will pass in front of the constellation Capricornus the Sea-goat on the evenings of September 24 and 25. Notice that Capricornus has the shape of an arrowhead.

White dots for the moon, Saturn, Capricornus, plus a green ecliptic line. — Chart via EarthSky.

September 26 and 27 evenings: Moon visits Saturn

The bright waxing gibbous moon will sweep past the planet Saturn on the evenings of of September 26 and 27. You need a telescope to see Saturn’s rings, but you might notice that the planet shines with a steady light and golden color.

White dots for the moon on 2 days and Saturn, plus a green ecliptic line. — Chart via EarthSky.

September 28 and 29, all night: Super Harvest Moon

The instant of September’s full moon – the last of four full supermoons of 2023 – falls at 9:57 UTC (4:57 a.m. CDT) on on September 29. For us in North America, the night of September 28-29 is our best for full-moon watching. But – as the closest full moon to the equinox – September 2023’s full moon also carries the name Harvest Moon. And the Harvest Moon is characterized by appearing full, or almost full – and by rising around the time of sunset for us in the Northern Hemisphere – for several nights following full moon. Read about the Harvest Moon.

2023 September 28 Harvest Moon — Chart via EarthSky.

September 29 and 30: Super Harvest Moon and Jupiter

The crest of the moon’s full phase falls early in the day on September 29. So – on the evening of September 29 – a bright full moon will rise soon after sunset, followed a little later by the bright planet Jupiter. Then on the evening of September 30, the waning gibbous moon will rise shortly after sunset, too. Why shortly after sunset when it’ll be after full moon? Because this was the Harvest Moon, which is characterized by appearing full, or almost full – and by rising around the time of sunset for us in the Northern Hemisphere – for several nights following full moon. On the nights of September 29 and 30, watch the Harvest Moon and Jupiter travel across the sky all night, until dawn. Read about the Harvest Moon.

The moon on September 29 and 30. — Chart via EarthSky.

Heads up! 2 great American eclipses coming

The first of two great American solar eclipses will take place on Saturday, October 14, 2023. Only those using proper eye protection – in a narrow swath sweeping over North and South America – will get to see the sun form a ring around the moon at mid-eclipse. But many more will observe a partial solar eclipse. Make sure you protect your eyes with eclipse glasses throughout this eclipse. Order them now!

Planets in September

Mid-September mornings: Venus and Mercury

Around now, for viewers in the Northern Hemisphere, Venus will climb higher each morning and will reach its greatest elongation on October 23, 2023. And Mercury will rise in the east shortly before sunrise. It will lie in the bright morning twilight near the similarly bright star Regulus and far below brilliant Venus. Mercury will brighten from magnitude -0.3 to -1.0 during the month. This is the best morning apparition for Mercury in 2023 for the Northern Hemisphere. Around greatest elongation, on September 22, Mercury rises about an hour before sunrise.

chart showing the positions of Venus, high in the sky, Regulus, lower down, and Mercury by the eastern horizon — Chart via EarthSky.

September mornings: Venus

After passing between the sun and Earth on August 13, 2023, brilliant Venus is up in the September dawn sky before sunrise. Venus will be brightest in the morning sky around September 19, 2023, and will reach 44 degrees elongation from the sun by the end of the month. Venus will brighten from magnitude -4.6 to -4.8 during the month. It’ll reach greatest elongation from the sun next month. The bright star Procyon of Canis Minor the Lesser Dog shines nearby. Venus will rise about 2 hours before sunrise at the beginning of the month and about 3.5 hours before by month’s end. The planet Mercury may be visible below Venus and near the horizon.

White dots for Venus and Procyon plus a green ecliptic line. — Chart via EarthSky.

September overnight: Jupiter

Jupiter is in the constellation of Aries the Ram during the month of September. It will shine near the pretty Pleiades star cluster. Jupiter will brighten from magnitude -2.5 to -2.7 during the month. Jupiter will rise about 10 p.m. (your local time) at the beginning of the month and will rise around 8 p.m. by month’s end. It’s high in the sky at dawn.

A white dot for Jupiter, plus a green ecliptic line and white dots for the star cluster Pleiades and Aries. — Chart via EarthSky.

September all night: Saturn

Saturn will lie in the southeast after sunset during September. It will be near the dim “Water Jar” asterism of Aquarius the Water Bearer. Saturn reached opposition on August 27, 2023, so it will remain well placed for observing this month. Saturn will shine at magnitude 0.5 during the month. The full Harvest Moon supermoon will visit Saturn on September 28, 2023. Saturn will rise and set with the sun at the beginning of the month and will rise before sunset and set about 3 hours before sunrise by month’s end.

Visible planets: White dots of different sizes for Saturn and the Water Jar asterism. — Chart via EarthSky.

Thank you to all who submit images to EarthSky Community Photos! View community photos here. We love you all. Submit your photo here.

Looking for a dark sky? Check out EarthSky’s Best Places to Stargaze.

Sky dome maps for visible planets and night sky

The sky dome maps come from master astronomy chart-maker Guy Ottewell. You’ll find charts like these for every month of 2023 in his Astronomical Calendar.

Guy Ottewell explains sky dome maps

Circle constellations, planets, the moon, the Milky Way and celestial lines. — View larger. | Here is the sky dome view for September 2023. It shows what is above the horizon at mid-evening for mid-northern latitudes. The view may vary depending on your location. Image via Guy Ottewell. Used with permission.

Heliocentric solar system planets

The sun-centered charts come from Guy Ottewell. You’ll find charts like these for every month of 2023 in his Astronomical Calendar.

Guy Ottewell explains heliocentric charts.

Circle with sun at center, planets around, and zodiac names on outer edge. — View larger. | Heliocentric view of solar system, September 2023. Chart via Guy Ottewell.

Some resources to enjoy

For more videos of great night sky events, visit EarthSky’s YouTube page.

Watch EarthSky’s video about Two Great Solar Eclipses Coming Up

Don’t miss anything. Subscribe to daily emails from EarthSky. It’s free!

Visit EarthSky’s Best Places to Stargaze to find a dark-sky location near you.

Post your own night sky photos at EarthSky Community Photos.

Translate Universal Time (UTC) to your time.

See the indispensable Observer’s Handbook, from the Royal Astronomical Society of Canada.

Visit Stellarium-Web.org for precise views from your location.

Almanac: Bright Planets (rise and set times for your location).

Visit TheSkyLive for precise views from your location.

Great resource and beautiful wall chart: Guy Ottewell’s zodiac wavy chart.

Cover of book with sky full of constellations over a camel caravan and title Astronomical Calendar 2023. — Amateur astronomers are buzzing! Guy Ottewell is offering his beloved Astronomical Calendar for 2023 in both electronic and printed versions.

A modern chair, a large plant and the zodiac wavy chart on the wall. — Guy Ottewell’s Zodiac Wavy Chart is a 2-by-3 foot (0.6 by 0.9 meter) poster displaying the movements of the sun, moon and planets throughout the year. You can purchase it here. Image via Guy Ottewell. Used with permission.

Bottom line: In September 2023, Mars is going into the sun. Jupiter and Saturn are evening objects. Morning planets are Venus and Jupiter, with Mercury low on the eastern horizon. Visible planets, here.

Posted

September 20, 2023

Astronomy Essentials

Marcy Curran

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About the Author:

Marcy Curran has enjoyed star gazing since she was a young girl going on family camping trips under the dark skies of Wyoming. She bought her first telescope in time to see Halley’s Comet in 1985. Her passion for astronomy eventually led her to being a co-founder of a local astronomical society. Marcy remains active in her astronomy club, including serving as the editor of a monthly newsletter. She also contributes a monthly article to her local newspaper focusing on the stars, planets and objects currently visible in the night sky. Marcy taught astronomy at her local community college for over 20 years.

John Jardine Goss

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About the Author:

“I can sometimes see the moon in the daytime” was a cosmic revelation that John Jardine Goss first discovered through personal observations at age 6. It shook his young concept of the universe and launched his interest in astronomy and stargazing, a fascination he still holds today. John is past president of the Astronomical League, the largest U.S. federation of astronomical societies, with over 20,000 members. He's earned the title of Master Observer and has authored the celestial observing guides Exploring the Starry Realm and Carpe Lunam. John also writes a monthly stargazing column, Roanoke Skies, for the Roanoke Times, and a bimonthly column, Skywatch, for Blue Ridge Country magazine. He has contributed to Sky and Telescope magazine, the IDA Nightscape, the Astronomical League’s Reflector magazine, and the RASC Observer’s Handbook.

Deborah Byrd

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About the Author:

Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. In 2020, she was the Education Prize from the American Astronomical Society, the largest organization of professional astronomers in North America. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.

Kelly Kizer Whitt

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About the Author:

Kelly Kizer Whitt has been a science writer specializing in astronomy for more than two decades. She began her career at Astronomy Magazine, and she has made regular contributions to AstronomyToday and the Sierra Club, among other outlets. Her children’s picture book, Solar System Forecast, was published in 2012. She has also written a young adult dystopian novel titled A Different Sky. When she is not reading or writing about astronomy and staring up at the stars, she enjoys traveling to the national parks, creating crossword puzzles, running, tennis, and paddleboarding. Kelly lives in Wisconsin.

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Visible planets and night sky for September