Will Comet A3 be visible in Arizona this fall? What to know

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

How about the possibility of a naked-eye comet?

Comet C/2023 A3, also known as Tsuchinshan–ATLAS, is making its 80,000-year journey through the solar system and could be a spectacular sight for skywatchers as it brightens while approaching Earth. Some are even calling it the “comet of the year” due to its potential visibility and brilliance.

Over the summer, astronomers were predicting heat from the sun would cause C/2023 A3 to break up. It survived the journey, though, and might become bright enough to become a naked-eye comet, a level of visibility that hasn’t occurred since Comet NEOWISE did a flyby in 2020.
While Comet C/2023 A3 is expected to brighten as it reaches its closest point to Earth, also known as perihelion, it might not brighten enough to achieve naked-eye status.

Claude Hayes of the East Valley Astronomy Club told Phoenix New Times that chances are “slim” that Comet C/2023 A3 will be bright enough to be seen without binoculars or a telescope.

“(Comets) are notoriously difficult to predict. I would also quote David Levy, 'Comets are like cats: They both have tails and do exactly as they please,’” Haynes says. “But even if it does brighten up and become a naked-eye comet, I recommend looking for it since it's always thrilling to see what our universe has to offer.”

Will C/2023 A3 be visible in Arizona in October? A few locals have seen it already, as its currently visible low on the eastern horizon during the early morning hours. Here’s how and when to look for it.

What is Comet A3?

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.

Can I see Comet A3 now?

Yes, but your viewing window is very brief. Comet C/2023 A3 in viewable only in the early morning hours over the next few days. It will sink lower into the horizon each morning before disappearing into the glare of the sun on Oct. 3 and transitioning to an evening comet.

When can I see Comet A3?

According to LiveScience, C/2023 A3 is an early morning comet that’s only visible around 30 minutes before sunrise Your chances of seeing it might be better starting on Oct. 12, it becomes an evening comet and will be visible around sunset.

Where do I look to see Comet A3?

It’s located in the eastern or southeastern skies a few degrees above the horizon.

Do I need binoculars to see Comet A3?

Yes. Haynes says the comet is only visible using binoculars or a telescope. "Binoculars are your friend in this case, so use them," he says.

Is Comet A3 visible over Arizona?

Yes. In late September, a local astrophotographer posted a photo of Comet C/2023 A3 over the Superstition Mountains to the Phoenix section of Reddit.

Is there an app to find Comet A3?

Yes. The local astrophotographer we previously mentioned recommends using SkyGuide to find Comet C/2023 A3. Haynes suggests using SkySafari, which requires a subscription.

When will Comet A3 be closest to Earth?

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 Comet A3 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.