Climate is what you expect, weather is what you get, goes the old definition. We know precious little about either on Saturn's giant moon Titan, the only planetary satellite with a significant atmosphere and the only body in the solar system other than Earth that has a thick atmosphere dominated by molecular nitrogen. Titan's 1.5-bar atmosphere looked bland and nearly featureless to Voyager 1's cameras in 1980. But as Griffith et al. report on page 509 of this issue, these first impressions were deceiving: Titan's atmosphere seems to have had a turbulent history and may today have a vigorous methane-based meteorology.
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