Actually, though, either order is correct. While most adjectives tend to follow their nouns, certain classes (mostly abstract concepts such as truth, beauty, quantity, etc.) typically precede. My own Latin knowledge is insufficient to say whether nova falls in this class, but in any case the order can be switched up for emphasis. Placing an adjective before its noun emphasizes the adjective (and if we allow poetic license, anything goes). Here’s a reference on typical word order from Wikipedia and another on moving adjectives around from D’Ooge’s Latin for Beginners.