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You Might Still Be Able to See Comet A3: Here's How

The ideal time to catch sight of Comet A3 has passed, but you might still have a chance.

Headshot of Thomas Kika
Headshot of Thomas Kika
Thomas Kika Former Writer
Thomas is a native of upstate New York and a graduate of the University at Albany. As a former member of CNET's How To team, he wrote about the intersection of policy, information and technology, and how you can best be served in that area. Outside of work, he can most often be found watching too many movies, reading too much, drinking too much coffee, or spending time with his cats.
Thomas Kika
2 min read
Green curve of Earth's atmosphere with bright splash of Comet A3 in the center.

Comet A3 makes a spectacular appearance in this image by NASA astronaut Don Pettit, taken from the International Space Station.

 Don Pettit/NASA

Comet A3 was visible for many folks just before sunrise on Thursday morning, and there might still be a chance for you to catch a glimpse of it.

Known officially as Comet Tsuchinshan-ATLAS, the celestial object reached a state known as its "perihelion" on Sept. 27, meaning the point at which it's closest to the sun. It'll reach the point closest to Earth in mid-October, and until then, eager stargazers will have a few opportunities to try to get a look at it.

Comet A3 has been on the radar of astronomers since its discovery early last year and has built up a significant amount of hype since then. In a press release from the Search for Extraterrestrial Intelligence Institute, aka SETI, Franck Marchis, director of citizen science at the institute, said A3 could become one of the brightest visible objects in the Northern Hemisphere's sky. Marchis also said A3 will be "as unpredictable as it is magnificent" and potentially "one of the most significant celestial events of the year or even the decade."

For more, read about the discovery of water on one passing comet and about why some have called A3 a contender for "comet of the century."

What is Comet A3?

Comet Tsuchinshan-ATLAS is a celestial body originating from the Oort Cloud, a massive shell of objects that encircles the solar system. 

It was first discovered in January 2023 and was named after the two observatories that spotted it in the sky, independent of each other. Scientists reckon the celestial traveler makes its way through our solar system every 80,000 years, leading Phys.org to note that the last time it passed by would've been when Neanderthals were still kicking around. 

When was the best time to see Comet A3?

Comet A3 was at its most visible in the wee morning hours on Thursday, Oct. 3, between 75 and 60 minutes before sunrise wherever folks were trying to see it, to the east-southeast and 18.2 degrees from the sun.

Will it be visible any other times?

If you missed out on the fun Thursday morning, Comet A3 will reappear just before sunrise this weekend, Oct. 4 to 6, though at this stage the glare from the rising sun is expected to make it much harder to spot.

A3 will also become visible in the twilight hours just after sunset later in the month, around Oct. 12, with that specific date being the point at which the comet will be the brightest during this phase. Observers should look west immediately after sunset during this time to try to catch a glimpse.

For more, check out the dazzling photos astronauts have snapped of Comet A3.