If having a comet visible to the naked eye in the sky does not happen every day, having two at the same time is a fairly unusual event: yet it is what could happen around the 20-21 Octoberwhen the comets C/2025 R2 (SWAN) And C/2025 A6 (Lemmon) they will reach their peak of brightness in conjunction with their slightest distance from the earth on their journey through the solar system. Both celestial bodies are currently visible from Italy with the help of appropriate tools and today they have reached the threshold of magnitude +6traditionally considered as the “technical” limit for visibility to the naked eye in a completely dark sky. In this case, according to the reference portal Astro.vanbuiten.nlSwan is positioned exactly at magnitude 6.0 While Lemmon a magnitude 5.8 (Recall that the more the magnitude of a body is low the more its brightness is high).
However, this does not automatically mean that if tonight we look up to the sky, we could see the two comets with the naked eye. There is first of all the difficulty of being under a night sky completely pollution without pollution light. But, also solved this problem, it should be remembered that The comets appear to us as extensive bodies In the sky, not point like the stars: this means that their brightness is “spread” in a certain area, making the actual body practically less brilliant than the only magnitude would suggest. As the two comets approach the earth, however, they will become more and more brilliant and cannot be excluded that, at the peak of their brightness, they can be also observe to the naked eye from the Italian skies.
Attention is mainly paid to comet C/2025 A6 (Lemmon)considered the “Autumn comet” of 2025, for which a magnitude around 3.5 when it reaches maximum proximity to our planet (150 million km) The 21 October. To be clear, a magnitude of 3.1 would make in principle – with comets the conditional is always a must! – The comet visible to the naked eye even in urban heavens. Even the position of the comet compared to the sun is favorable, since it will be visible for about 3 hours after sunset. The visibility window will extend instead up to 6 hours after sunset for comet C/2025 R2 (SWAN)which will have its slightest distance to the earth (40 million km) The October 20th with a magnitude around 5.5.
The show will be embellished with the fact that in those days we will witness the peak of the method of the method of the method Orionidsone of the most intense of the year, expected Between 20 and 23 October. Soon we will therefore be able to witness two comets visible simultaneously in the peak of their brightness simultaneously with the peak of a swarm of “falling stars”!
