The physical plane isn't actually Geocentric. The universe in its entirety is part of the physical plane in that it is physically there. The astral planes are just layers over and under that existence. Your subtle consciousness can only manifest where its density matches its surroundings. Therefore, the part of your consciousness that astral projects manifests directly into the astral planes. However that being said doesn't mean you can't see the physical plane. Once more the planes are just layers of existence, wherever you travel on the astral planes you're technically right there in the space of the physical only on different frequencies and densities.
Hope this answers your question.