Is it illegal to own Mars?

Isn't it fascinating to ponder the legality of owning an entire planet like Mars? As a matter of fact, can you actually lay claim to celestial bodies in the first place? With space exploration on the rise, is there any legal framework that governs the ownership of extraterrestrial territories? Is there an international law or treaty that addresses this topic specifically? Wouldn't ownership of Mars imply sovereign rights over its resources and potential future inhabitants? It's certainly an intriguing question that raises a multitude of ethical, practical, and legal considerations.