This September brings a plethora of celestial wonders, including a stunning partially eclipsed supermoon, optimal planet viewing, and the possibility of vibrant northern lights. The month is packed with reasons to look up and enjoy the night sky, with opportunities for stargazing across the globe. Whether you’re equipped with binoculars or just using the naked eye, these are the events you won’t want to miss.
For the best views, consider heading to a dark-sky location, such as a stargazing hotel or remote site, to escape city lights. Here’s a guide to this month’s top night-sky attractions and tips for capturing the perfect view.
September 5: Mercury’s Greatest Western Elongation
On September 5, Mercury will be easier to spot than usual, as it reaches its greatest western elongation. This event, occurring just before sunrise, places Mercury farthest from the sun, making it visible in the eastern sky from around 5:45 to 6:15 a.m. ET. Look toward the eastern horizon with Mars, Jupiter, and Uranus lined up diagonally above it. Mercury will shine brightly with a -0.3 magnitude, making it visible to the naked eye, though binoculars may enhance your view.
September 7: Saturn at Opposition
Saturn takes center stage on the night of September 7 as it reaches opposition, positioning itself directly opposite the sun from Earth’s perspective. The ringed planet will shine at its brightest of the year, with a magnitude of 0.57. After sunset, look toward the east-southeast horizon in the constellation Aquarius, where Saturn will appear as a yellowish dot. While visible to the naked eye, a telescope will provide a closer look at Saturn’s stunning rings.
September 17: Partially Eclipsed Full Harvest Supermoon
The highlight of September’s celestial events is the partially eclipsed harvest supermoon on September 17. This supermoon, the second of four in 2024, will treat stargazers to a partial lunar eclipse visible across the U.S. (excluding Alaska), western Europe, parts of Asia, and Africa. The eclipse begins around 8:41 p.m. ET as the moon enters Earth’s outer shadow, with the peak eclipse occurring from 10:13 to 11:16 p.m. ET. This is a rare opportunity to witness the signature “bite” of an eclipse alongside the bright supermoon glow.
September 20: Neptune at Opposition
On September 20, Neptune reaches its closest approach to Earth, offering one of the best viewing opportunities of the year. While Neptune is too distant to be seen with the naked eye, stargazing binoculars or a telescope will reveal its bluish disc. Look above the east-southeast horizon, with Saturn visible nearby to guide your search. This is the perfect time to glimpse Neptune’s remote beauty in the night sky.
September 22: September Equinox
The September equinox occurs on September 22, marking the start of autumn in the northern hemisphere and spring in the southern hemisphere. As the sun crosses the celestial equator, aurora watchers may be in for a treat. Equinoxes are known to intensify aurora activity, so this is a prime time to catch a dazzling northern lights display. Whether you’re using an app to track auroras in the contiguous U.S. or planning a trip to an aurora hotspot, the days around the equinox offer an excellent chance to see this natural phenomenon. On the same night, the moon will pass near the Pleiades star cluster, adding another stunning sight to the celestial calendar.
September 22: Chicagohenge
While Manhattanhenge may be more famous, Chicago has its own solar alignment spectacle. On September 22, the sun will align perfectly with Chicago’s east-west streets during sunrise and sunset. For a perfect view, watch from Washington Street near Millennium Park or E. Randolph Street between State Street and Michigan Avenue. The sun will rise at 6:45 a.m. and set at 7:02 p.m. local time, providing a photogenic solar display framed by the Windy City’s skyline.