There is already great anticipation, especially among NASA experts, for the imminent passage near our planet 3I/Atlaswhich sparked debate among experts about its real nature due to a series of unusual characteristics for a comet.
The space object, identified for the first time on 1 July 2025 by the ATLAS project telescope located in Chile, from which it took its name, is certainly one of those that has most attracted the attention of scholars, first and foremost for the rare possibility of observing a comet born outside our Solar System, potentially a harbinger of new information and interesting ideas for expanding knowledge about the characteristics of these celestial bodies.
It is therefore not surprising that NASA is using a significant number of resources to record its passage and analyze its trajectory and its chemical composition. Privileged observation point due to its “proximity”, given that Atlas arrived 30 million kilometers away, it was Mars: the Mars Reconnaissance Orbiter, a space probe launched on 12 August 2005, provided the most detailed and incredible images. A valuable contribution was also made MAVEN (acronym for Mars Atmosphere and Volatile EvolutioN), a mission that aims to study the atmosphere and evolution of the Red Planet: the probe, which entered orbit in 2014, collected data in the ultraviolet band, fundamental results for understanding which gases Atlas is emitting on its path towards our star. Perseverance also managed to capture an image of him, even if it was not very clear.
And what about observations from our planet? Invisible to ground-based telescopes due to the intensity of sunlight, the comet was first observed thanks to the mission STEREO (“Solar TErrestrial RElations Observatory”, launched by NASA in 2006) from 11 September to 2 October and then by the mission SOHO (“Solar and Heliospheric Observatory”, launched by NASA and ESA in 1995) from 15 to 26 October. The system too PUNCH (“Polarimeter to Unify the Corona and Heliosphere”, a NASA mission composed of 4 satellites) managed to track the tail of the comet between 20 September and 3 October, as well as the two probes traveling towards asteroids as distant from us as Psyche (8-9 September, at 50 million kilometers) e Lucy (September 16 at 240 million km). The combinations of all this information collected over the months will be invaluable for scholars.
Now there is great excitement about the closest passage to Earth (270 million
kilometres), expected on Friday December 19th: It will be impossible to see Atlas with the naked eye, but all telescopes will be pointed towards its wake. Once this phase has been overcome, the celestial body will continue towards Jupiter.