With the State of California recently listing the objects at Tranquility Base as a historic site (for a recent story on this see here), I have been thinking again about the intersection of national and world heritage, and the legal issues around interpreting the extension of national jurisdictions into space as equivalent to making territorial claims.
Australia has the potential for an interesting twist here. Only heritage places on national territory of some kind can be registered on the Commonwealth Heritage List, but there is the capacity to recognise sites of significance to Australia in foreign territories on the List of Overseas Places of Historic Significance to Australia.
The List of Overseas Places of Historic Significance to Australia recognises symbolically sites of outstanding historic significance to Australia located outside of the Australian jurisdiction.
It was established by the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) on 1 January 2007. With this new list, Australia can recognise and celebrate those overseas places of greatest importance to the development of our nation in a way that is respectful of the rights and sovereignty of other nations. The list helps tell the story of the most significant parts of Australia's history that occurred outside our borders.
OK, so the overseas bit isn't perhaps helpful here, but you could certainly argue that space was "over the sea" in terms of being above the sea, if one wanted to get all semantic. The respectful of the rights and sovereignty of other nations bit is more helpful in terms of the Outer Space Treaty.
Currently there are three places on the Overseas List: Anzac Cove (Turkey), the Kokoda Trail (Papua New Guinea), and Howard Florey's Laboratory (UK).
What if we wanted to list Australia's historic satellites in orbit? There's really only two, Australis Oscar V and FedSat (still in orbit as far as I know). The Overseas List is symbolic, so it does not imply a territorial claim. You could argue that California's listing of Tranquility Base is just as symbolic, given that enforcing it may prove more than slightly tricky. But there is a legal difference here that may be worth exploring.