Global winds on Uranus (Figure 10.14c) have been studied less than those of the other giant planets. When Voyager 2 flew by Uranus in 1986, the northern hemisphere was in complete darkness, and only a few clouds were observed in the southern hemisphere. The strongest winds observed were 650-km/h westerlies in the middle to high southern latitudes, and no easterly winds were seen. More recently, as Uranus approached equinox season, terrestrial observers reported wind speeds of up to 900 km/h.