Question

What caused the Earth to tilt at that number?

1 There is more land on one dide. 2 Jupiter's gravity pulls off center .3 We were hit by another planet. 4 The Earth spins so quickly that we are pulled off to an angle​

Answer 1

The angle varies a little over time, but the gravitational pull of the moon prevents it from shifting by more than a degree or so. This tilt is what gives us seasons. The Earth's axis always points the same direction, so as the planet makes its way around the sun, each hemisphere sees varying amounts of sunlight.