Comet Lemmon 2025: Where and When to Watch the Once in 1,150 Years Comet?

Tonight, skywatchers across the country can look forward to an exceptional event, as they will be able to see Comet Lemmon (C/2025 A6), a visitor from the distant past who will not return for over a thousand years. The comet was discovered earlier this year by the Mount Lemmon Survey in Arizona. As it nears the Sun, it has been getting progressively brighter. During this close approach, it has taken on its striking green color and developed a wispy tail.

 It should be visible shortly after sunset in the northwestern sky and will provide a great show for both astronomy aficionados and casual stargazers alike this evening. Tonight should contain many clear skies, which makes it the perfect opportunity for people to step outside and look up at the wonders of nature, and for many, it will be the only chance in a lifetime, a once-in-a-lifetime trip across the night sky that will not be repeated until the year 3175.

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From tonight:

Here are all of the satellites we have to deal with while observing the Lemmon Comet. 🍋 Our night skies are badly polluted and it’s only going to get worse.#comet #lemmon pic.twitter.com/xJPJIccnJY

— Landon Moeller (@landon_wx) October 27, 2025

Best Time to View Comet Lemmon

Tonight, between 7:00 PM and 7:30 PM EDT, is the best time to view Comet Lemmon, which is approximately 90 minutes after sunset. This short time frame is when the comet will be in the northwestern sky, just west of the Big Dipper, near the bright star Arcturus which will help you locate it.

 The crescent moon, which is waxing at 24% and will set early, gives a darker sky, which means there will be less light interference and the comet will be easier to see. It is recommended to find a dark sky space far from city lights. With binoculars or a small-telescope, you will see a faint, fuzzy green view of Comet Lemmon and its beautiful, delicate tail. This is a rare opportunity to view Comet Lemmon as a once-in-a-lifetime comet viewing event!

How to Spot Comet Lemmon?

To observe Comet Lemmon, begin by gazing into the northwest sky after sunset, around 7PM to 7:30 PM EDT. It is crucial to first identify the Big Dipper, which is one of the easiest constellations to find. After identifying the Big Dipper, you will be able to follow the arc of its handle until you arrive at the bright star Arcturus. 

From Arcturus, draw a right-angle line toward the star Rasalhague, part of the constellation of Ophiuchus, where the comet will appear. Look for a diffuse, fuzzy patch with a faint green glow and possibly a faint tail. 

Binoculars, such as 8×42 or 10×50 magnification, can provide an enhanced view of the comet. The green color of the comet is caused by solar radiation vaporizing the icy materials in the nucleus, resulting in this breathtaking view. 

Why This Event Is Special?

The arrival of Comet Lemmon (C/2025 A6) is an unrepeatable astronomical event as it will not return to our skies for another 1,150 years. That means everyone that is reaching out tonight is seeing a historical event that will not take place again in their lifetimes. 

Lemmon will have traveled millions of miles through space to be visible from Earth with its bright green appearance and faint tail. A rare orbit makes the present moment historically important for both astronomers and skywatchers. The comet last passed through the inner solar system in AD 875. It will not return until approximately 3175. Unlike meteors or solar eclipses that happen every year or so, this is a special sighting of a cosmic object that can take us from the present to the distant future.