Fall officially began with the autumnal equinox at 8:43 a.m. Eastern time on Sunday. It marked the time of year when we see the most rapid decline in the length of daylight, which is nearly three minutes per day around Washington, D.C.

Although the term “equinox” means “equal night,” the combination of the sun’s substantial disc, atmospheric refraction, and the way sunrise and sunset are defined, the actual date when we have exactly 12 hours of daylight won’t occur until Wednesday. However, longer nights mean more time for stargazing!

A trio of moons and a ‘ring of fire’ solar eclipse

There will be three full moons between the fall equinox and the winter solstice. They occur on Oct. 17, Nov. 15, and Dec. 15 and are called the Hunter’s Moon, the Beaver Moon and the Cold Moon, respectively.

The Oct. 2 new moon will produce the year’s second solar eclipse. Unlike the well-observed total solar eclipse seen by millions of people across the United States last April, this will be an annular eclipse that will only be visible from the Pacific Ocean, parts of South America and Antarctica. During an annular eclipse, the moon is too far away to block the entire sun but leaves behind a so-called “ring of fire” or circle of light around its periphery. Residents of Hawaii will see a partial eclipse at sunrise, when about half of the solar disc will be hidden by the moon.

For 57 days this fall, Earth will have a second moon

From Sept. 29 to Nov. 25, a passing asteroid will be pulled in by Earth’s gravity, before returning to its normal orbit around the sun. Objects that get captured by our gravitational force for a short time are known as mini-moons.

You won’t really be able to see this mini-moon without a professional telescope. At 33 feet long, it is too small for our eyes, and its closest approach is still five times farther than our permanent moon.

Planets return!

Autumn will see a return of bright planets to the evening sky. Saturn reached opposition, with the Earth positioned between it and the sun, on Sept. 8 and is now visible all night long. Look for the ringed planet’s yellow glow in the southeastern sky as evening twilight ends. If you have a telescope, you may wonder what has happened to the planet’s stately rings. At first glance they look like spikes sticking out of the planet’s sides. This is because Saturn will reach one of its equinoxes next spring and its rings will seem to disappear!

The bright glow of Venus is now visible just after sunset, low in the western sky in evening twilight. The dazzling planet will become easier to see as autumn progresses and, by November, should be easy to spot in the southwestern sky. It will remain a bright beacon in the evening until well into the new year.

Jupiter reaches opposition on Dec. 7. It will be prominently placed among the bright stars that form the Winter Circle asterism, or star pattern. Jupiter is a treat to see in a telescope. Its four bright Galilean moons shift their positions from night to night, and modest instruments can show its famous Great Red Spot, a storm system the size of the Earth that’s persisted for some 300 years.

There could be a comet

What may possibly be the celestial highlight of the season is an object with the name Comet A3 Tsuchinshan-ATLAS. Discovered in January 2023, this object was showing cometary activity while still far from the sun. Speculation was that, if it survived its closest approach to the Sun, it might be visible to the unaided eye in October of this year.

Recent observations have shown that the comet is indeed brightening, and it is very possible that it will be visible to even city dwellers in early- to mid-October. Even if it doesn’t dazzle from the city, it should be easy to spot from darker sites. However, comet maven David Levy has said many times before, “Comets are like cats: They have tails, and they do precisely what they want.”

Astronomy nights in the D.C. area this fall

The night sky awaits! Here are some places to look through a telescope this month if you live in the D.C. area.

• George Mason University Observatory offers free public lectures and telescope tours every week.
• Analemma Society Observatory offers public night sky observing events at Turner Farm Park in Great Falls, Va.
• National Capital Astronomers hosts “Exploring the Sky” every month between April and November in Rock Creek Park in the District.
• The Astronomical Society of Greenbelt will host several star parties at night and Astronomy Day (Oct. 2) activities in the coming weeks.
• The Northern Virginia Astronomy Club will host public observing nights at C.M. Crockett Park in Midland, Va., on Sept. 28, Oct. 26 and Nov. 30.
• The National Air & Space Museum’s Udvar-Hazy Center will host a stargazing event on Oct. 19 and Nov. 8.
• Virginia’s Department of Conservation and Recreation offers “Astronomy for Everyone” at Northern Virginia’s only International Dark Sky Park on Oct. 5, Nov. 2 and Dec. 7.

For a list of astronomy clubs, planetariums, science centers and observatories in the region, see this compilation from the U.S. Naval Observatory.

Kasha Patel contributed to this report.