TOSeptember is almost about to end, but October will no less generous than celestial appointments. It does not often happen, in fact, to be able to observe a comet. But even more difficult, it is that you understand to see twoin the same month. However, that’s what will happen just soon, when The sky above Italy will host both the C/2025 R2 (SWAN) and the C/2025 A6 (Lemmon)two very different comets, but both ready to leave their mark.
C/2025 R2 (Swan), the comet that I will illuminate the autumn sky
Starting in chronological order, The first to pass will be, between 12 and 19 October, the comet C/2025 R2 (SWAN). The show will also be visible to the naked eye always that they are clear evenings. This comet, however, is not a traveler of any sky: according to astronomers, in fact, He will return to visit us only between over 22,000 years. In other words, it is a unique and unrepeatable opportunity.
Discovered by chance, destined to amaze
The comet was identified on September 12 of this yearthanks to the Swan tool aboard the SOHO space probe. Its name, in fact, derives from there: Solar Wind Anisotropiesa system that monitors the solar wind and that, in this case, has intercepted a bright and unexpected object. From that moment, the interest of the experts has grown quickly. One of the most fascinating aspects is its tail: already today extends for about 2.5 degrees in the sky, the equivalent of five full moons flanked. A vision that, if the conditions will allow it, It can also be admired by the simple fansonati, with the help of binoculars or a camera.
Between 12 and 25 October, two comets will cross the sky above Italy: Swan, with its spectacular tail, and Lemmon, brighter and constant (Getty Images)
Where and when to watch Swan
This beautiful loose light will be visible between 12 and 19 October, in the south-west direction. For those who observe from Italy, the best period will be shortly after sunset. The comet will appear low on the horizon, in a south-west direction. To see it, it will be essential to choose a place with a free horizon: no trees, buildings or mountains and wait for the sky to be dark. Like all comets, however, Swan is also capricious. Its brightness can suddenly increase or drop without notice. But, both this unpredictability and the fact and will return to visit over 22 thousand years, Which means that those who see it today will do so for the only time in human history, make observation even more exciting.
Lemmon: brighter, closer
The story of C/2025 A6 (Lemmon)the comet discovered on January 3 by the Mount Lemmon Survey in Arizona. It is not a difficult comet to intercept. On the contrary: it will be among the brightest of the yearvisible throughout October even to the naked eye, even from cities. It does not have Swan’s scenic tailbut has something more immediate: a strong, clear presence that imposes itself in the sky without asking for permission. Lemmon, it’s not a frequent visitor, returns every thousand years, but when he arrives, he stands out. His close passage is scheduled for October 21stand will be visible for days from Italy. They will not need tools: just look up to the sky and let yourself be surprised.
C/2025 R2 (SWAN) and C/2025 A6 (Lemmon): two comets, two stories
If Swan fascinates for his extended tail and his “unique” character, Lemmon strikes for the brightness and ease of observation, both comets offer a rare opportunity for those who love to look at the sky: an October in which wonder will be double and accessible to everyone. There is no need to be astronomy experts. Just choose one evening, a dark and quiet place. Without asking too many questions: certain things, like the comets, for example, do not explain: they look at each other, they remember, they tell each other.