1) Cosmographist 2) Man of science 3) Scientist 1) Cosmographist 
• (n.) One who describes the world or universe, including the heavens and the earth.
Cos·mog'ra·pher noun One who describes the world or universe, including the heavens and the earth. « The name of this island is nowhere found among the old and ancient cosmographers . Robynson (More's Utopia). » 
[n] - a scientist knowledgeable about cosmography
cosmographer 1. A general description of the world or of the universe. 2. The science that describes the constitution of the whole order of nature.
cosmographist noun a scientist knowledgeable about cosmography