Starting today, in the skies of Italy it is technically possible to observe two comets with the naked eye: C/2025 R2 (SWAN) And C/2025 A6 (Lemmon). Both have just reached enough brightness to be visible without optical instruments, but to actually see them requires some ideal conditions. The highlight of the observation will be between 20 and 21 October 2025when they will be at the minimum distance from Earth and reach their peak brightness.
SWAN and Lemmon: two comets visible to the naked eye
It’s not every day you get to admire a comet visible to the naked eyelet alone two in the same period. Yet, this very phenomenon is occurring in the month of October 2025. Comets C/2025 R2 (SWAN) And C/2025 A6 (Lemmon) they are crossing the Solar System and, as they approach Earth, they are increasing in brightness.
Both have reached the threshold in these hours apparent magnitude +6considered the technical limit beyond which a celestial object can theoretically be seen without the aid of telescopes or binoculars, as long as the sky is perfectly dark and free of light pollution. In particular, according to the specialized site astro.vanbuitenen.nlSWAN is now at magnitude 6.0, while Lemmon is slightly brighter at magnitude 5.8. It is important to remember that, in the magnitude system, the lower the value, the brighter the object.
Lemmon will be the autumn comet of 2025: up to 3 hours of evening visibility
The celestial body that attracts the most attention is undoubtedly the comet C/2025 A6 (Lemmon)already renamed by experts as the “autumn comet”. On October 21st it will reach its minimum distance from Earth, equal to approximately 150 million kilometersand at that moment he might touch one magnitude of 3.5making it much brighter than now.
A magnitude around 3.1, in theory, would make the comet visible even in urban skiesbut with comets caution is a must: the perceived brightness can vary greatly due to their diffuse nature. In fact, unlike stars which appear as bright dots, comets appear as extended objects in the sky, and therefore their light is distributed over a larger surface, making them less obvious to the naked eye.
An additional advantage is the favorable position in the sky: Lemmon will be visible until 3 hours after sunsetthus offering a wide evening observation window even for those who are not used to getting up early at night.
SWAN will be closer and visible for longer
The comet C/2025 R2 (SWAN) will reach his minimum approach to Earth on October 20alone 40 million kilometers away. Although its brightness will be lower than that of Lemmon, with an estimated magnitude of around 5.5, the duration of visibility will be longer: it will be possible to observe it until 6 hours after sunsetan interesting opportunity for those who wish to follow the entire phenomenon in ideal conditions.
At the same time, the Orionids will also light up the sky: shooting stars and comets
Lo will also make this double celestial event even more spectacular Orionid meteor showerwhich will reach his peak between October 20th and 23rd. This is one of the most anticipated meteor showers of the year, and coincides with the maximum brightness of the two comets could give as a gift one of the most fascinating night skies of 2025.
Those who find themselves under a dark sky and far from artificial lights could be lucky enough to see, in a single night, two comets with the naked eye and dozens of meteors cross the celestial vault.
