One of the brightest comets to light up our skies in decades will make an appearance across Canada and the United States this month.  

Orbax, a physicist and science communicator for the Department of Physics in the University of Guelph’s College of Engineering and Physical Sciences, says this rare comet, named Comet C/2023 A3, will be visible throughout North America again on Oct. 12, when it will rise in the night sky above the western horizon. The best viewing of what’s being heralded by star gazers as the “comet of the century,” will occur between Oct. 12 and 20, as the comet moves away from the sun. 

Orbax says this is one of the brightest comets in our lifetimes, and it hasn’t even reached full brightness yet. C/2023 A3 also has a massive tail, which occurs when the celestial ice ball gets close to the sun, heats up and turns to gas and debris. 

“The tail is so long and bright that it may even be visible with the unaided eye,” Orbax says. 

Comet C/2023 A3 was visible in the morning skies across the northern hemisphere in early September but disappeared into the sun’s glare over the past few weeks. As it makes its closest approach to the Earth on Oct. 12, it may even be bright enough for people to see during the day. 

“The northern hemisphere will be uniquely favoured as a viewing location, which hasn’t occurred for quite some time,” Orbax adds. 

As for why we can see these comets from Earth, Orbax says it’s because we’re seeing the debris from these celestial entities falling apart right before our eyes. 

“Comets are notoriously unpredictable and can literally just break apart into pieces at any given time,” he says. “We’ll keep our fingers crossed for optimal viewing conditions for stargazers.” 

Orbax is available for interviews. More information is available in this month’s Star Gazing Guide. 

Contact: 

Orbax   
orbax@uoguelph.ca