Colorado's renowned dark skies provide some of the best stargazing opportunities in the country, and over the next two weeks, astronomy enthusiasts can witness the comet of the year if they know where and when to look.
The comet is C/2025 A6, also known as Comet Lemmon, and was only discovered this January. Some may remember last year's Comet Tsuchinshan-ATLAS, which was also an October spectacle and one of the brightest comets in the last century. While Comet Lemmon won't be as bright, it will be visible with the naked eye.
Understanding Comets and Their Brightness
Comets are cosmic snowballs made of ice, dust and rock clumped into a rough ball shape. Most exist in the far reaches of our solar system, but occasionally the orbit of a comet brings it close to the sun and it warms up. This creates a fuzzy gas cloud around the comet called a coma and also produces the bright long tail comets are famous for.
Prime Viewing Timeline and Conditions
Comet Lemmon has been brightening steadily as it hurtles closer to the sun. It should be visible to the naked eye in a dark location from now through early November. It will be closest to Earth on Oct. 21, but it should continue to brighten after that for the next 7-10 days.
Helping viewing chances, the moon will be in its new phase and not visible on Oct. 21.
At peak, it should be about as bright as the dimmest star of the Big Dipper — the one at the top of the bowl where it connects to the handle. That's also where you should look to see it.
Where and How to Spot Comet Lemmon
Look to the northwestern sky after sunset in a spot with a clear view of the horizon, not blocked by mountains. The comet will be near and beneath the Big Dipper's handle. Each night the comet will move back and to the left relative to the Big Dipper and it will be visible higher in the sky and for more time after sunset.
I suggest using the free phone app Stellarium to help you pinpoint exactly where to look. Make sure to give your eyes 20 to 30 minutes to adjust. You can also use your phone's night photo mode to better see the comet.
If you capture any photos of this comet, please share them with us — we'd love to see them through the News 5 We Want to Know tab.
Additional Resources:
Why Colorado is great for stargazing
Colorado's International Dark Sky Sites
____
Have a question or story idea you would like the First Alert 5 Weather team to consider? Email: weather@koaa.com
Watch KOAA News5 on your time, anytime with our free streaming app available for your Roku, FireTV, AppleTV and Android TV. Just search KOAA News5, download and start watching.
