Bright comet Tsuchinshan-ATLAS could be visible without a telescope for the 1st time in 80,000 years. Here's how to see it this week.
During late September and mid-October, the much-anticipated comet C/2023 A3 (Tsuchinshan-ATLAS) could become visible to the naked-eye for skywatchers around the world.
Get the world’s most fascinating discoveries delivered straight to your inbox.
You are now subscribed
Your newsletter sign-up was successful
Want to add more newsletters?
Join the club
Get full access to premium articles, exclusive features and a growing list of member rewards.
Are you ready for a naked-eye comet? Although there are never any guarantees when it comes to comets, astronomers have high hopes that Comet C/2023 A3 (Tsuchinshan-ATLAS) will be visible in the hour before sunrise on four successive mornings this week. Further windows of naked-eye visibility in the evening sky could follow in mid-October.
C/2023 A3 is expected to peak in brightness on Friday, Sept. 27, when it reaches perihelion, its closest point to the sun on its estimated 80,000-year-long orbit. Skywatchers in the Northern Hemisphere will be able to glimpse the comet a few degrees above the east-southeast horizon about 30 minutes before sunrise between Friday, Sept. 27 and Wednesday, Oct. 2.
Perfect mornings to view it include Sunday, Sept. 29 and Monday, Sept. 30, when C/2023 A3 will be joined by a delicate waning crescent moon.
Article continues belowAlthough C/2023 A3 may be visible to the naked eye, comets can be fickle and difficult to predict, so it may be wise to have a good pair of stargazing binoculars or a small telescope to enhance the view.
However you view the comet, it should be possible to see a sizable dusty tail, a consequence of the comet's constituent dust and ice slightly melting as it approaches the sun. How bright it will get remains a mystery, though some astronomers predict it could be as luminous as the 20 brightest stars in the night sky.
Related: Betelgeuse, Betelgeuse? One of the brightest stars in the sky may actually be 2 stars, study hints
By Sept. 30, C/2023 A3 will have disappeared into the light of dawn for those in midnorthern latitudes, but anyone close to the equator should still be able to see C/2023 A3 until Oct. 2. After that date, the comet will be lost in the sun's glare, destined to reemerge into the Northern Hemisphere's night sky around Saturday, Oct. 12, when it will be at its closest point to Earth. It will then be positioned close to the western horizon.
Get the world’s most fascinating discoveries delivered straight to your inbox.
After that, C/2023 A3 will gradually fade from view.

Jamie Carter is a Cardiff, U.K.-based freelance science journalist and a regular contributor to Live Science. He is the author of A Stargazing Program For Beginners and co-author of The Eclipse Effect, and leads international stargazing and eclipse-chasing tours. His work appears regularly in Space.com, Forbes, New Scientist, BBC Sky at Night, Sky & Telescope, and other major science and astronomy publications. He is also the editor of WhenIsTheNextEclipse.com.
