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If you think back to the original Voyager pictures of Uranus, it was just kind of a pale blue ball with nothing on it. You didn’t see clouds, you didn’t see haze, you didn’t see anything … so there was a polar cap then, but we couldn’t see it, what we’ve been watching over time (using Hubble), is this buildup of this high-altitude haze in the atmosphere, and the exact purpose or the exact mechanism behind it, we don’t know, that’s one of the things we’re studying.