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
Alien Legacy of the system. The Beta Caeli system is similar to our real-life solar system, with a barren, rocky inner planet, terrestrial planets in the habitable zone of the inner system, followed by gas giants in the outer system that first increase and then decrease in size, and a tiny rock outermost. The naming of the Caelian planets closely matches that of naming planets in our solar system. But while our system uses the names of Roman deities (except for Uranus), Caeli has Greek ones; Gaea is the Greek goddess of the Earth, and Rhea is her daughter. In addition, as