Retrograde and prograde motion with retrograde rotation – are Venus and Uranus. Venus's axial tilt is 177°, which means it is rotating almost exactly in the opposite direction to its orbit. Uranus has an axial tilt of 97.77°, so its axis of rotation is approximately parallel with the plane of the Solar System. The reason for Uranus's unusual axial tilt is not known with certainty, but the usual speculation is that during the formation of the Solar System, an Earth-sized protoplanet collided with Uranus, causing the skewed orientation. It is unlikely that Venus was formed with its present slow retrograde rotation, which takes 243
Atmosphere of Uranus 50° latitude (first appeared in 2007) have grown more conspicuous since then. The atmosphere of Uranus is calm compared to those of other giant planets. Only a limited number of small bright clouds at middle latitudes in both hemispheres and one Uranus Dark Spot have been observed since 1986. One of those bright cloud features, located at −34° of latitude and called "Berg", probably existed continuously since at least 1986. Nevertheless, the Uranian atmosphere has rather strong zonal winds blowing in the retrograde (counter to the rotation) direction near the equator, but switching to the prograde direction poleward of ±20°