The concept of ownership manifests itself if there exists entities (or agents) and limited set of resources to share between entities. An entity owns a resource

The concept of ownership manifests itself if there exists entities (or agents) and limited set of resources to share between entities. An entity owns a resource if it can assert control over it and deny control over it to others. It's pretty brutal but in the end, that's kind of what it is. If you dissolve all governments, teleport us on a new world and wait to see what happens, ownership will develop based on this. No one "owns" Jupiter at this time. If one day someone manages to deny access to Jupiter to others, while having access to it, that person will probably reasonably "own" Jupiter.