3I/ATLAS is the third interstellar object identified crossing our solar system, and the second one exhibiting a cometary appearance. Pre-and post-perihelion photometric observations, inner coma imagery, and a spectroscopic comparison with CR and CH carbonaceous chondrites will be presented. The spectral similarities found are consistent with 3I/ATLAS, being a carbonaceous object, likely enriched in native metal and undergoing significant aqueous alteration during its approach to the Sun, like the hydrated chondrites widely observed in the Solar System(Trigo-Rodríguez et al., 2019). The extensive corrosion experienced due to its porous nature and the presence of reactive minerals, experiencing energetic Fischer–Tropsch reactions, makes it develop a new kind of cryovulcanism, similar to the pristine Trans-Neptunian Objects in our own planetary system. We proposed that the combination of elevated metal abundance and abundant water and ice can account for the unusual coma morphology and chemical products reported to date, particularly the overabundance of Ni in the coma (Trigo-Rodríguez et al. 2025). In consequence, the study of interstellar objects such as 3I/ATLAS, gravitationally scattered eons ago, provides unique opportunities to study physico-chemical processes occurred in minor bodies of our own Solar System, including transitional bodies similar to trans-Neptunian objects from the Solar System. I envision that the ESA's planned Comet Interceptor mission, and future sample return missions to new interstellar visitors exhibiting DeltaV favorable encounter conditions, can provide a pleyade of new information on the formation of planetary systems across our galaxy. Given the extraordinary catalytic potential of carbonaceous chondrites to promote complex organics under aqueous alteration (Rotelli et al., 2016), such discoveries could promote a significant breakthrough in our knowledge on the ubiquity of organic life in the Universe.

References:

Rotelli L. et al. (2016) Nature Sci. Rep., 6:38888.

Trigo-Rodríguez J. et al. (2019) Space Sci. Rev. 215:18, 27 pp.

Trigo-Rodríguez, J. et al. (2025) ArXiv: 2511.19112