Sent in By Robert – www.centauri-dreams.org/2018/07/03/uranus-orbital-tilt-from-a-cataclysmi… …. the excessive tilt in the orbit of Uranus was caused by a cataclysmic collision, we are informed. This seems to have been provoked by the discovery that exoplanets can have tilted orbits. In our solar system the Earth is titled at 23 degrees and Uranus by 98 degrees – but in contrast Mercury has a small tilt, at only 0.3 degrees. The amount of obliquity affects seasonality. A new paper on Uranus which spins on it side with the axis at right angles to the other planets has intrigued people for a long time. Its moons are also affected and the status quo recognises that perhaps a collision of some kind was responsible. Researchers have simulated 50 different impact scenarios, or so they say, in an attempt to recreate the amount of axial tilt. They have opted for a collision with an object twice the size of the Earth. Clearly, they had not read Peter Warlow's 'tippetop' thoery where torque is required rather than an actual impact.
See also https://phys.org/print449757619.html … where it is theorised the impactor struck a grazing blow to Uranus.