Which planet rotates on its side?

The planet that rotates on its side is Uranus. This unique axial tilt—approximately 98 degrees—means that Uranus essentially rotates with its axis almost perpendicular to its orbit around the Sun. As a result, it experiences extreme variations in its seasons, with each pole getting around 42 years of continuous sunlight followed by 42 years of darkness.

Uranus's unusual tilt is thought to be the result of massive collisions with other celestial bodies during its formation, which may have knocked it onto its side. This distinct characteristic sets it apart from the other planets in our solar system, most of which have a more upright rotation.

In contrast, Earth, Jupiter, and Saturn have axial tilts that are much less extreme, allowing them to rotate in a more conventional manner as compared to Uranus. Understanding these differences helps highlight the diverse physical characteristics that exist among the planets in our solar system.