Light

"the phenomena of the heavenly bodies undoubtedly are in those undiscovered solitudes. What may not be expected in a country of eternal light?" (1)

Light, like fire, is a symbol of knowledge in this novel. Robert Walton is pursuing a knowledge that no other man has discovered. He does not know what to expect to find there or how it will effect him. This situation is parallel to Frankenstein's, when he creates life.