[uf-discuss] Proposal: Lunar/ Mars co-ordinates (like "geo")

[Michael MD]

> That would give us, say:
>
>         <span class="luna">
>                 <span class="geo">
>                         <span class="latitude">37.386013</span>,
>                         <span class="longitude">-122.082932</span>
>                 </span>
>         </span>
>

what is the reference point for longitude?
(I assume some reference point would have to be defined equivalent to
Greenwich for geo on Earth)