Here's why:

* Celestial bodies are not owned. International law, specifically the Outer Space Treaty of 1967, states that celestial bodies, including planets, moons, asteroids, and dwarf planets, are the "province of all mankind." This means no country or individual can claim ownership.

* Ceres is a celestial body. Ceres is a dwarf planet located in the asteroid belt between Mars and Jupiter.

* Exploration is allowed. The treaty encourages exploration and scientific research, but prohibits national appropriation of celestial bodies.

While no one owns Ceres, various space agencies, including NASA and the European Space Agency, have sent missions to study it. The information gathered from these missions is available to everyone for scientific advancement.