Comet C/2023 A3 (Tsuchinshan–ATLAS) is one of the most anticipated celestial events of 2024. Discovered in January 2023 by observatories in China (Tsuchinshan) and the ATLAS survey in Hawaii, this comet is making its way toward the inner solar system. With its highly elliptical orbit, it promises to become visible to both amateur and professional astronomers alike as it nears the Sun and brightens dramatically.

A Brief Introduction to Comets

Comets are icy bodies originating from the outer regions of the solar system, specifically the Kuiper Belt and the Oort Cloud. As they approach the Sun, their surfaces begin to heat up, causing the ices to vaporise and form a glowing coma around the nucleus, along with a tail of gas and dust that points away from the Sun due to solar wind and radiation pressure. These "dirty snowballs" are remnants from the formation of the solar system, and their highly eccentric orbits allow them to occasionally make spectacular visits to the inner solar system, providing skywatchers with a cosmic show.

What to Expect from C/2023 A3 in Mid-to-Late October 2024

As we move into mid to late October 2024, C/2023 A3 (Tsuchinshan–ATLAS) is expected to be at its brightest, potentially visible to the naked eye under dark skies. While its actual brightness is still subject to some uncertainty, preliminary estimates suggest it could reach magnitude 4 to 5, making it faintly visible even without telescopes or binoculars in areas with minimal light pollution. Observers should keep an eye out for its coma and tail, which may become visible as the comet nears its perihelion (closest approach to the Sun) on October 12, 2024.

For Southern Hemisphere observers, this comet could become a morning object, gracing the pre-dawn skies. However, the best views will likely be just before sunrise, meaning timing and sky clarity will be critical for catching a glimpse of this celestial visitor.

Personal Observations from Southern Adelaide

From the Southern Adelaide suburbs, we have been trying to catch a glimpse of C/2023 A3 early in the morning, between 05:00h and 05:15h. On September 29th, 30th, and October 2nd, we were out observing, but the low altitude of the comet and the rapidly brightening sky made it a challenge. We could only start scanning the sky when the comet was about 10 degrees above the horizon, and by the time it got any higher, the sunrise was already washing out the faint glow by around 05:15h. Even so, we did manage to get a small amount of observing time with our Celestron 10x50 binoculars.

Unfortunately, the weather didn’t cooperate on October 1st—cloud cover obscured the sky, and we missed the chance to observe that morning. Despite these setbacks, we remain hopeful for clearer skies and perhaps better visibility as the comet continues to brighten.

Challenges of Early Morning Observations

Observing a comet like C/2023 A3 in the pre-dawn hours comes with its own set of challenges. The most obvious hurdle is the timing—the comet is visible low on the horizon during a small window before sunrise. Given that Adelaide is well into the southern hemisphere's spring, the mornings are getting brighter earlier, leaving little time to catch a glimpse of the comet. Additionally, urban light pollution and local weather conditions, such as humidity or cloud cover, can further complicate viewing.

In our experience, even with a good pair of binoculars or a small telescope, the comet has remained elusive, barely distinguishable from the brightening twilight. However, as October progresses and the comet reaches its peak brightness, there’s hope for clearer, more rewarding views.

Final Thoughts: Why Observing Comets is Special

Comets offer a fleeting, once-in-a-lifetime opportunity to witness the dynamic nature of our solar system. C/2023 A3 (Tsuchinshan–ATLAS) is no exception, and while the conditions may be challenging, the reward of seeing this ancient traveler firsthand is worth the effort. For amateur astronomers like us, there’s something deeply personal about the chase—waking up early, scanning the skies, and braving the elements, all in the hopes of seeing a distant object that has journeyed for millions of years.

If you’re an amateur astronomer or even just curious, we highly recommend giving this comet a shot. Whether you're armed with binoculars, a small telescope, or just your eyes, C/2023 A3 promises to be one of 2024's astronomical highlights, and with a little patience and some early mornings, you might just get a glimpse of this ancient wanderer from your backyard.