September offers a rich array of celestial events, including the possibility of heightened northern lights, prime planet visibility, and an extraordinary lunar sight: a partially eclipsed supermoon. For the best stargazing experience, seek out dark-sky locations, such as dedicated stargazing hotels, and consider bringing binoculars or opting for accommodations with telescopes. Many of this month’s celestial events, however, are visible to the naked eye.
Sept. 5: Mercury Reaches Greatest Western Elongation
On September 5, Mercury, the innermost planet of our solar system, will be at its greatest western elongation, meaning it will be positioned farthest from the sun in the sky. This event occurs around 11 p.m. ET on September 4, but Mercury will be visible from approximately 5:45 to 6:15 a.m. ET on September 5. With a magnitude of -0.3, it is visible to the naked eye, appearing as a bright spot between Sirius and Polaris. Look towards the eastern horizon to catch Mercury alongside Mars, Jupiter, and Uranus arranged in a diagonal line above it.
Sept. 7: Saturn at Opposition
Saturn will reach opposition on September 7, showcasing its stunning rings. This celestial event occurs when Saturn is positioned directly opposite the sun from Earth’s perspective. It will shine at its brightest magnitude of 0.57. Observe Saturn as a yellowish dot moving above the east-southeast horizon in the constellation Aquarius after sunset. While Saturn is visible to the naked eye, a backyard telescope will provide a clearer view of its magnificent rings.
Sept. 17: Partially Eclipsed Full Harvest Supermoon
If you missed August’s supermoon, September offers another chance. On the evening of September 17, the full harvest moon—one of four supermoons in 2024—will be partially eclipsed. Stargazers in much of the world, including the U.S. (excluding Alaska), western Europe, parts of Asia, and Africa, can witness this event starting around 8:41 p.m. ET as the moon enters Earth’s outer shadow. The partial eclipse, characterized by a noticeable “bite” taken out of the moon, will last from 10:13 to 11:16 p.m. EDT.
Sept. 20: Neptune at Opposition
On September 20, Neptune will reach opposition, making it one of the best nights to view the distant planet in 2024. The opposition occurs around 6:45 p.m. ET, bringing Neptune closest to Earth. It will be visible throughout much of the night above the east-southeast horizon. Look for Saturn, visible to the naked eye, to the right of Neptune for a combined celestial view.
Sept. 22: September Equinox
The September equinox on the 22nd marks the sun’s crossing of the celestial equator, heralding autumn in the northern hemisphere and spring in the southern hemisphere. Equinoxes often bring enhanced aurora activity, so it’s a great time to monitor northern lights forecasts. For those keen on witnessing the auroras, consider planning a trip to an aurora hotspot. Additionally, the moon will approach the Pleiades star cluster, known as the Seven Sisters, offering a captivating view.
Sept. 22: Chicagohenge
Chicago will experience its own version of a solar alignment on September 22, similar to Manhattanhenge. The sun will align perfectly with the city’s east-west streets during sunrise and sunset, at 6:45 a.m. and 7:02 p.m. local time, respectively. Ideal viewing spots include Washington Street from Millennium Park and E. Randolph Street between State Street and Michigan Avenue, as recommended by Secret Chicago.
Conclusion
September’s night sky offers a plethora of astronomical events, from planet sightings to lunar eclipses and unique solar alignments. Whether you’re using high-powered telescopes or simply observing with the naked eye, these celestial events promise a memorable stargazing experience.