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Comet C2023-A3, or Tsuchinshan-ATLAS, was pictured about 99.4 million miles away from Earth by NASA astronaut Matthew Dominick using long-duration photography on a camera programmed for high sensitivity aboard the International Space Station
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Comet C2023-A3, or Tsuchinshan-ATLAS, was pictured about 99.4 million miles away from Earth by NASA astronaut Matthew Dominick using long-duration photography on a camera programmed for high sensitivity aboard the International Space Station (Photo from NASA website)
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A comet has gotten a lot of attention recently.

The comet C/2023 A3 was discovered by the Purple Mountain Observatory in China on January 9, 2023, and was also found independently by the Asteroid Terrestrial-impact Last Alert System (ATLAS) in South Africa on February 22, 2023.

This is the first time that this comet has been seen, because of how far away the comet came from.

"This thing comes from so far, that it's actually not very well known how far it came from," explains Associate Professor of Astronomy at the University of Calgary Jeroen Stil. "It a region that we generally designate as the OORT Cloud and it takes millions of years for this comet to go around the sun. So, this comet has not been seen previously by people."

That's fairly unique compared to other comets, such as Halley's Comet which is visible every 72-80 years.

Stil says the comet is on track to becoming visible in the sky in a couple of weeks.

The comet will be visible in the Foothills County from October 12-20.

"People from the Southern Hemisphere are seeing it right now and it's looking nice. It's coming closer to us, it's getting a little bit brighter even for our evening sky," Still says.

Still adds that the comet still has to make its closest pass to the sun, which can be tricky, especially if the material the comet is made of is fragile.

"There are some people that are concerned, Will it break up when it comes closest to the sun? So far, it's doing quite well. There are other people that say it's breaking off until it passes by the sun. We haven't seen this comet from up close, so we're keeping our fingers crossed." 

The comet will reach its closest point to the sun this Saturday (Sept. 28).

Stil says that if it survives passing by the sun, there is a good chance there will be a nice show visible from Foothills County.

"If the predictions hold up, it's worth it for people, on October 12th and the days after, if the weather is good, to find a spot with a clear horizon to the west and look for the comet, on October 12th, really low in the west," Stil explains.

The comet will then climb up the sky over the next few nights, but the comet will be at its brightest on October 12, just after dusk.

Stil suggests looking for the comet around 7 p.m., and he adds that if the comet does hold up while passing the sun, the comet won't be hard to see.

"There is a bit of uncertainty on how bright the tail is. It depends on how much stuff comes off the comet. This is just a piece of debris left over from the solar system," Stil says. "Think of it as a ball of debris and ice that is a couple of kilometres across."

As the comet passes the sun, there is a chance that it could pick up more debris or gas.

The sunlight reflected off of the solid bits of debris surrounding the comet, known as dust, is what gives the comet its glow.

Stil says the last time a comet like this was visible from Earth was the NEOWISE comet in 2020.

In the days leading up to October 12, the comet will be really close to the sun, so Stil is reminding everyone not to attempt to view the comet during the day as it could cause retinal damage.