​Use adjectives ending with -ian to describe something belonging to or relating to a person, like we do with planets

We use adjectives ending with -ian to describe something belonging to or relating to a planet. You wouldn’t say “the surface of Mars” or “the atmosphere of Neptune” or “the moons of Jupiter”, rather “the Martian surface”, “the Neptunian atmosphere”, “the Jovian moons”. We also do this sometimes with other words like Shakespearean.

Why don’t we start referring to people this way? Instead of saying “Alex’s phone” or “Emily’s house” or “Sam’s car” say “the Alexian phone”, “the Emilian house”, “the Samuelian car”, to make everybody sound like a celestial object!