Cometa ATLAS (C/2024 G3) sobre el Río de la Plata y la Isla San Gabriel, visto desde Colonia del Sacramento, Uruguay, el 20 de enero de 2025.

Comet ATLAS (C/2024 G3): How & when to see it from the Southern Hemisphere

The brightest comet of 2025?

The LASCO C3 imagery equipment aboard the SOHO spacecraft caught Comet ATLAS (C/2024 G3) – possibly the brightest comet of 2025 – as it crossed the field of view of the cameras aboard during the last 3 days, January 11-14, 2025. Image via NOAA.

Comet ATLAS C/2024 G3 has been in the spotlight in recent weeks and could be the brightest comet of 2025. Detected by the Asteroid Terrestrial-impact Last Alert System (ATLAS), this comet is visible at its brightest from the southern hemisphere. Here's how to observe it.

Comet ATLAS reached its perihelion (its closest point to the Sun) on 13 January 2025 and thanks to images from the LASCO C3 instrument on the SOHO spacecraft we can see it passing close to the Sun. This comet appeared even brighter in the near-Sun images than comet C/2023 A3 (Tsuchinshan-ATLAS), the brightest comet in 27 years, which was visible in the sky only a few months ago.

Cometa ATLAS - C/2023 A3 (Tsuchinshan–ATLAS) - Fefo Bouvier

Photo by Fefo Bouvier. Comet Tsuchinshan-ATLAS A3 on October 20, 2024, from Colonia, Uruguay. Comet Tsuchinshan-ATLAS A3 was the brightest comet of 2024. Will comet ATLAS G3 be the brightest of 2025?

Comet G3 survived its close passage to the Sun and is expected to be extraordinarily bright over the next few days. You will be able to observe it with binoculars or perhaps with the naked eye—depending on the sky conditions and if you are an experienced astronomical observer.

How bright is comet ATLAS?

The website In-the-Sky predicted that the comet reached magnitud -4.9 during its closes passage to the Sun on January 13, 2025. Such a bright object would be visible in the daytime sky, but at the time it was too close to the Sun to be observed. Now, the comet is moving away from the Sun and will gradually lose brightness, but it is bright enough to be seen through binoculars and small telescopes. It is even possible to see it with the naked eye as a faint and diffuse whitish object. The comet is a great subject for astrophotography at the moment.

Comet C/2024 G3 (ATLAS) captured over the Río de la Plata and San Gabriel island, as seen from Colonia del Sacramento, Uruguay, on January 16, 2025, by Fefo Bouvier.

Photo by Fefo Bouvier. Comet ATLAS (C/2024 G3) over the Río de la Plata and San Gabriel Island, as seen from Colonia del Sacramento, Uruguay, on January 16, 2025.

How to see comet ATLAS

If you live in the southern hemisphere, look for it about an hour after sunset for the rest of the month. The comet appears in the direction of the setting sun.

Is it possible to see comet ATLAS with the naked eye?

Yes, but it is a challenge. The comet is already visible to the naked eye for those with astronomical observing experience and eagle eyesight. For the rest of the mortals, I recommend using binoculars.

Is it possible to photograph comet ATLAS?

Definitely. As shown in the image below, Fefo Bouvier captured comet ATLAS again on 20 January from Colonia del Sacramento, Uruguay. Compared to the previous image from 16 January (higher up), the comet's nucleus is no longer as bright as it was a few days ago—due to a presumed disintegration—but its tail is now longer, more complex and brighter.

Comet C/2024 G3 (ATLAS) captured over the Río de la Plata and San Gabriel island, as seen from Colonia del Sacramento, Uruguay, on January 20, 2025, by Fefo Bouvier.

Photo by Fefo Bouvier. Comet ATLAS (C/2024 G3) over the Río de la Plata and San Gabriel Island, as seen from Colonia del Sacramento, Uruguay, on January 20, 2025.

How long will it be possible to see and photograph comet ATLAS?

The comet will be visible through binoculars and in astrophotographs during the nights throughout January.

Practical tips for observing comet ATLAS:

  • Look for dark skies: Stay away from city lights to get a clearer view of the comet over the western horizon.
  • Use instruments: Try with binoculars or a small telescope first so you can find it faster. Then try to find it with the naked eye. Good luck!
  • Use astronomy apps: Apps like Stellarium will help you locate it in the sky.

I will keep this article updated as new information becomes available and if I manage to capture it in more pictures.


Stay up to date on this and other astronomical events

🌌 Follow my stories and astrophotography on Instagram

Back to blog

1 comment

Increíble las fotos felicitaciones 👏👏

santiago aguiar

Leave a comment

Please note, comments need to be approved before they are published.

1 of 4