The final months of 2025 are shaping up to be remarkable for comet watchers. Above is my pic of comet C/2023 A3 (Tsuchinshan–ATLAS) taken with my phone last October, 2024. Three very different icy bodies are drawing attention now: Comet Lemmon, Comet SWAN, and the interstellar comet ATLAS. Each object offers its own story and a unique perspective on how comets travel through space.
Comet C/2025 A6 (Lemmon)
Discovered by the Mount Lemmon Survey in January 2025, Comet Lemmon is the brightest prospect for observers in the Northern Hemisphere.
- Closest approach to Earth: October 20–21, about 55 million miles (89 million kilometers).
- Closest approach to the Sun (perihelion): November 8, about 49 million miles (79 million kilometers).
- Visibility: Morning sky in early October, shifting to the evening sky after October 20.
Forecasts suggest the comet could reach magnitude 4, making it visible to the naked eye under dark skies and easier to see with binoculars. Around October 16, it will pass close to the star Cor Caroli in Canes Venatici, a useful marker for locating it. Later in the month, the comet moves toward Arcturus in Boötes, better placed for evening viewing.
Comet Lemmon has the best chance of becoming a memorable sight, though comets often defy predictions. Sudden outbursts can brighten them dramatically, while fading or fragmentation can diminish their impact.
A great free site to see exactly where the comet is at any time and location is https://theskylive.com/c2025a6-info
Comet C/2025 R2 (SWAN)
Comet SWAN was discovered in September 2025 using the SWAN camera aboard the SOHO spacecraft. It is less prominent than Lemmon but still worth watching.
- Closest approach to Earth: Mid-October, about 25 million miles (40 million kilometers).
- Brightness: Expected to reach around magnitude 5.8, visible with binoculars under dark skies.
- Visibility: Best positioned for observers in the Southern Hemisphere.
For observers in North Carolina and much of the Northern Hemisphere, the comet will be low in the sky after dusk, competing with twilight glow. This makes it more difficult to see. Even so, its faint green coma and developing tail may be visible with optical aid.
3I/ATLAS: An Interstellar Visitor
The most scientifically significant of the three is Comet 3I/ATLAS. This is only the third confirmed interstellar object observed passing through our solar system, following ‘Oumuamua in 2017 and Comet Borisov in 2019.
- Perihelion: October 30, at 130 million miles (210 million kilometers) from the Sun.
- Closest approach to Earth: About 170 million miles (270 million kilometers).
- Key feature: Not bound to the solar system. Its hyperbolic trajectory confirms an origin from another star.
While too faint for casual observation, 3I/ATLAS is important to planetary scientists. Early observations show water and carbon dioxide ices, similar to solar system comets. Continued monitoring may reveal chemical differences that help us understand conditions in other planetary systems.
Why These Comets Matter
Together, these comets highlight different aspects of celestial exploration.
- Lemmon is a rare opportunity for the public to see a bright comet without advanced equipment.
- SWAN demonstrates how sudden discoveries can add unexpected complexity to the night sky.
- ATLAS provides direct evidence of material from beyond our solar system.
All three reinforce the same lesson: the universe is not static. Objects move, evolve, and pass by Earth on timescales that remind us of the vastness and unpredictability of space.
Observing From Charlotte, NC
As I live in the Charlotte, NC area, I’m providing details from here, but most applies to anyone in the continental US. Adjust for your latitude. The farther north you are, the lower the comet sits in the sky and the later you may need to look. The farther south you are, the higher and easier the view.
For practical viewing:
- October 10–20: Look northeast before dawn for Comet Lemmon. Binoculars are recommended.
- October 16: Lemmon passes near Cor Caroli, making it easier to locate.
- October 20 onward: Shift to the northwest after sunset as Lemmon moves into the evening sky.
- October 12–19: Comet SWAN is at its closest. Low on the horizon after dusk, visible with binoculars if conditions allow.
- Late October: Interstellar Comet ATLAS will be at perihelion. It is telescope-faint, so public images from observatories will be the best way to follow it.
Final Thoughts
October and November 2025 offer a rare opportunity to experience three comets with very different stories. One may become visible to the naked eye, another will be a binocular target, and the third is a scientific milestone. Whether you step outside with binoculars or follow observatory updates online, these visitors remind us of how dynamic and interconnected the universe truly is.


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