you are likely to find Planet in/at/on Galaxy. Galaxy is similar to Universe. Nature is a type of Universe. Nature is related to Preserve. 
Speculation is a synonym of Guess. Guess is related to Hypothesis. 
Planet --AtLocation--> Galaxy <--SimilarTo--> Universe <--IsA-- Nature <--RelatedTo--> Preserve 
Speculation <--Synonym--> Guess <--RelatedTo--> Hypothesis 