Best Things to See in the September Night Sky

Skygazers can observe multiple meteor showers, rare planetary alignments with the moon, and the annual autumnal equinox throughout September, according to federal and space agency schedules.

Aurigids and Southern Taurids Meteor Showers

September hosts two distinct meteor showers, starting with the Aurigids peaking on the evening of Sept. 1, according to the National Park Service. Fueled by the C/1911 N1 Kiess comet, this minor shower lasts four or five days. Meteors appear to originate from the Auriga constellation, which rises from the northeastern horizon shortly after midnight on Sept. 1.

The Southern Taurids begin later in the month on Sept. 20. Running through Nov. 20, this two-month event is fueled by the 2P/Encke comet, which also fuels the Northern Taurids arriving in October, according to the National Park Service. While most meteors won’t be visible until the shower peaks in early November, late September observers may spot occasional stray meteors originating from the Taurus constellation, which rises past 1 a.m. in the eastern sky.

Moon and Planet Meetups in September

The moon will align closely with four visible planets over an eight-day span in September, according to astronomical tracking data. The sequence begins early on Sept. 7 when the moon and Mars rise together over the northeastern horizon shortly after 3 a.m. local time. On Sept. 8, the moon rises alongside Jupiter.

Mercury joins the sequence on Sept. 12 at sunset, offering a brief viewing window before sinking below the horizon. Finally, the moon aligns with Venus on Sept. 14 and Sept. 15 immediately following sunset.

New Moon Visibility and Venus at Its Brightest

A new moon occurs on Sept. 11, sitting directly between Earth and the sun to make the lunar disk invisible, according to observational data. Because the moon is the primary source of night sky light pollution, its absence improves visibility for fainter celestial objects, though urban light pollution remains a factor. Observers have a weeklong window of reduced moonlight around this date.

On Sept. 18, Venus reaches its highest evening brightness. The planet is visible in the western sky along the horizon just after local sunset, making it easily distinguishable unless obstructed by buildings or trees.

Fall Equinox and Neptune Opposition

The fall equinox officially begins on Sept. 22 at 8:05 p.m. ET, marking the moment the sun passes through Earth’s celestial equator, according to NASA and NOAA weather satellites. The event delivers roughly 12 hours of daylight and 12 hours of night across the Northern Hemisphere.

Neptune reaches opposition on Sept. 25, positioning itself between Saturn and the moon. During opposition, the planet drifts closest to Earth along its orbit and receives full sunlight, aiding amateur astronomers using high-powered binoculars or telescopes, despite potential light pollution from the approaching full moon on Sept. 26.

September Harvest Moon

The full moon peaks on Sept. 26 at 12:49 p.m. ET, according to lunar tracking data. Because peak illumination occurs mid-day, the brightest viewing windows occur the prior morning before sunrise or the following evening after sunset. While September’s full moon is traditionally called the corn moon, it earns the designation of harvest moon this year as the full moon closest to the autumn equinox.

September Constellations and Asterisms

September marks the seasonal transition from summer to autumn skies, bringing distinct constellations into view. Observers can spot Cygnus, Lyra, Aquila, Pegasus, Capricornus, Aquarius, Cassiopeia, Ursa Major, Ursa Minor, Cepheus, and Delphinus throughout the month. Summer constellations like Cygnus, Lyra, and Aquila will sink progressively lower toward the horizon as the month advances.