Is the earths axis tiled or is its or is its orbit causing the seasons?

Question

a tilted earth would cause the seasons but couldn't the earth be going round the sun so sometimes the south pole and sometimes the north pole is pointing to the sun imagine a planet going round a star but the axis is sometime parallel and sometime perpendicular as it orbit why couldn't this cause our seasons

Answer 1

Tom -

It does cause the seasons. Since the earth's axis is tilted in a way that it always points toward Polaris and is not fixed relative to the sun, the northern hemisphere is tilted toward the sun on one side of the orbit and tilted away from the sun on the other side of the orbit. So it's resulting in summer on one side of the orbit and winter on the other. Of course, the southern hemisphere sees summer and winter on the opposite sides of the orbit vs. the northern hemisphere. During spring and fall, the earth is tilted neither toward nor away from the sun, but sideways facing the sun, so temperatures in both hemispheres are moderate.

Answer 2

The planet Uranus is tilted like that, its North pole is tilted 98 degrees from its orbit.  So the days and nights are not like ours.

But ... the tilt of a planet does not change (or it changes slowly, over 1000's of years).  Earth is always 23.5 degrees tilted from its orbit.  Stand outside near a tree, and imagine your head is the Earth.  The tree is the sun.  Tilt your head about 23 degrees,  and walk around the tree.  always facing the same direction (looking toward some building, for example).   Part of the time, your head is tilted toward the sun (the tree), and part of  the time your head is tilted away from the sun --- but your tilt does not change!