The Northern Lights are a wonder to behold when you know a little bit about the science behind the spectacle. I can only imagine what people must have thought in the past, when solar radiation wasn't understood at all.
I think there are two fairly common natural phenomenon that we experience, for which we should never lose our sense of wonderment. Some think that wonders cease when we can define them in scientific terms. I disagree completely, since we can understand the causes of phenomena and still gaze in awe. The two wonders that always leave me awestruck are rainbows and auroras. I am lucky to live in an area where I can see both and wish everyone would have the same opportunity at least once.