Interstellar visitor 3I/ATLAS has been constantly changing as it makes its way through our solar system. Thats to be expected, as, for the first time in potentially billions of years, it's getting close to the energy put out by a star. Scientists have been keeping a close watch on those changes, both to ensure theres nothing unexplainable by our current understanding, but also to compare 3I/ATLAS to both previous interstellar visitors as well as comets in our own solar system. A recent paper from European researchers describes how the changes in a particular material ratio in 3I/ATLAS coma fit with our current understanding of cometary geology.