Will Comet A3 be visible in Arizona tonight? What to know

Editor's note: This story was published Sept. 28. It was updated on Oct. 11.

Pop quiz, skywatchers: How do you top a solar eclipse, supermoons, rare appearances by the northern lights and other spectacular astronomical wonders we’ve witnessed in 2024?

How about a comet that hasn't been seen for 80,000 years?

Comet C/2023 A3, also known as Tsuchinshan–ATLAS, is making its closest approach to Earth starting this weekend and could be a spectacular sight for skywatchers. Some even call it the “comet of the year” due to its visibility and brilliance.

The comet, which was discovered in 2023 by astronomers in China, can be seen just after sunset in the western skies. Here’s more information about how to find it.

What comet is visible tonight?

Comet C/2023 A3, also known as Tsuchinshan-ATLAS, is a comet that originated from the distant Oort Cloud surrounding our solar system. It was discovered independently in early 2023 by China's Tsuchinshan Observatory and the ATLAS asteroid tracking system. According to NASA, it won't be visible again for another 80,000 years.

when can I see Comet A3 tonight?

Comet C/2023 A3 will be visible approximately 45 minutes after sunset each night beginning on Oct. 12 through the end of the month.

Where can I see Comet A3?

Comet C/2023 A3 is located low in the western/southwestern skies about 10 degrees above the horizon between the constellations Sagittarius and Scorpio.

Do I need binoculars to see the comet?

No, but they always help. Comet A3 can be seen without binoculars or a telescope, but Claude Haynes of the East Valley Astronomy Club says they allow you to see more. "Binoculars are your friend in this case, so use them," he says.

Is Comet A3 previous visible over Arizona?

Yes. In late September, Comet C/2023 A3 was visible before dawn in the eastern skies. A local astrophotographer posted a photo of the comet over the Superstition Mountains to the Phoenix section of Reddit.

Is there an app to find Comet A3?

Yes. Local astronomers recommend using SkyGuide to find Comet C/2023 A3. Haynes suggests using SkySafari, which requires a subscription. Both apps will help you locate Sagittarius and Scorpio.

Where is Comet A3?

According to Earth Sky, Comet C/2023 A3 will reach its closest point to Earth on Oct. 12 and 13. At its nearest point, it will be approximately 70 million miles (or 113 million kilometers) from our planet.

Will the comet hit Earth?

Thankfully, no. Astronomers worldwide have been studying the comet and its orbit and trajectory for more than a year and have said there’s zero chance it will impact our planet.