What is the best day to see the “comet of the century”? This will be the last thing that can be seen with the naked eye for a long time.

Saturday, October 12, will be the best time to view Comet Tzuchinshan-ATLAS, known as the “comet of the century,” as it reaches its closest approach to Earth. This will also be the last opportunity to see the comet with the naked eye in the night sky for a long time, according to Nahum Mendez Chazzarra, a geologist and scientist.

In these first days of October, the comet will temporarily disappear due to its proximity to the Sun, but closer to the middle of the month it will experience a rebirth. It will begin to recede, becoming more visible in the twilight. Every day at dusk it will rise higher in the sky and become easier to spot. Starting October 14, its distance from the Sun will be sufficient to observe it after sunset in clear places.

Comet C/2023 A3 (Zuchinshan Atlas) was discovered by astronomers early last year and is believed to orbit the Sun every 80,000 years, meaning Neanderthals were still walking the Earth when it was last seen.

Seen like stars

This comet is a visual spectacle with a brightness comparable to that of the brightest stars, thanks to its abundant dust particles. However, its low height above the horizon and its appearance at dawn make it difficult to observe. A physical phenomenon known as forward scattering may increase its luminosity. “When the sun’s rays illuminate the comet’s coma, dust and ice particles will reflect the sunlight, which is scattered towards the observer,” says astrophysicist Josep Maria Trigo from the Institute of Space Sciences (ICE – CSIC).

After being hidden for a while, it will become visible in the sky again. This phase will be more favorable for observers in the southern hemisphere, although it will also be visible from higher, clearer locations in countries such as Mexico, Spain and Portugal.

“Comets visible to the naked eye are already quite rare, and this comet has the potential to be one of the brightest we have seen in decades. So it’s definitely worth a try,” says Royal Greenwich Observatory astronomer Gregory Brown. in The Guardian.

Although it will be very bright at times, it is recommended to go somewhere further away and with a good view of the horizon. It is important to let your eyes adjust to the darkness and look slightly above the comet rather than keeping it in the center of your field of vision. Using this “distracted seeing” technique, you will have one last opportunity to observe it with the naked eye or through binoculars before its final departure.