What to See in the Night Sky in September

Joshua Tree National Park glows at night. (Photo: Henrique Pinto [public domain]/Wikimedia Commons)

After a summer that featured Tesla's spaceman completing a full orbit around the sun, a muted Perseid meteor shower in August, and the 50th anniversary of the Apollo 11 mission, it's been an eventful time in the galaxy we call home. What could September possibly offer for an encore? Plenty, it turns out.

Dust off that sweatshirt, grab a blanket, and enjoy the waning weeks of summer while you're looking up into the evening sky. Below are just some of the highlights.

India's Chandrayaan-2 mission arrives at the moon (Sept. 6)

a model of India's shuttle rover
An engineering model of the Chandrayaan-2 rover, displayed at the 6th Bangalore Space Expo in September 2018. (Photo: Dean Sumith [CC by SA 4.0]/Wikimedia Commons)

India successfully launched its second lunar exploration mission back in July, sending an orbiter, lander and rover to the south pole of the moon. A touchdown would be truly historic for the country, as only the United States, China, and Russia have accomplished a moon landing. None of those landings were in the south polar region, though, which is where India's mission is headed. India isn't the only one with its eyes on the south pole — NASA plans to land astronauts there in 2024.

Neptune gets up close and personal (Sept. 10)

a size comparison of Neptune and Earth
Neptune is about 17 times bigger than Earth. (Photo: NASA [public domain]/Wikimedia Commons)

This is the best day of the year to see Neptune, as it makes its closest approach to earth, which happens when it's almost directly opposite of the sun. Even at its closest, you'll still need a telescope, as it'll look more like a bright star when viewing with just your naked eye.

Dial up Neil Young for this Harvest Moon (Sept. 14)

a full, orange moon appears over DC horizon
The Harvest Moon appears over the horizon in Washington, D.C. (Photo: CTDPIX [CC by SA 4.0]/Wikimedia Commons)

The "Harvest Moon" will reach full phase at 12:33 a.m. EDT. This type of full moon can occur in either September or October, since it's tied to an astronomical event: the autumnal equinox. What's with the name? It's called that because it provides the most light at a crucial time of year: to gather and complete the harvest!

Slide into fall (Sept. 23)

fall color in trees with moon glowing above
The fall equinox occurs in the Northern Hemisphere at exactly 3:50 a.m. EDT. (Photo: Julia Prudska [CC by SA 3.0]/Wikimedia Commons)

The first day of autumn in the Northern Hemisphere will officially arrive on this day, and for our friends in the Southern Hemisphere, it's the first day of spring! At 3:50 a.m. EDT, we'll say goodbye to the lazy days of summer and welcome the start of fall with the autumnal equinox. According to Time and Date this event marks "the moment the sun crosses the celestial equator — the imaginary line in the sky above the Earth’s equator – from north to south and vice versa in March." It's also a good time to start thinking about firewood, carving pumpkins, warmer clothing, and an anticipation of the colder months that lie ahead. (According to the Farmers' Almanac, we're going to have a frigid one.)

The return of the aurora, Zodiacal light (late September)

zodiacal light in the western sky at sunset
Zodiacal light is sometimes called 'false dawn' when it appears. (Photo: Mike Lewinski [CC by 2.0]/Flickr)

This celestial object (aka the Zodiacal light) also signals the start of fall for the Northern Hemisphere. It's described as a "cone-shaped glow," similar to the Milky Way's dusty look, but made out of comet and asteroid dust. For best viewing, look up your local sunrise time and back that up two hours — and make plenty of coffee to keep you awake as this "false dawn" appears.