WordNet records no synonym and no antonym for cosmography. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
the science that maps the general features of the universe; describes both heaven and earth (but without encroaching on geography or astronomy)
a representation of the earth or the heavens
“the cosmography of Ptolemy”
Synonyms, antonyms and the broader and narrower relations for cosmography come from Princeton University’s WordNet. Full sources and licences.