Which planet has an axis of rotation parallel with the plane of its orbit?

1 Answer
Jul 2, 2016

No planet has its axis exactly parallel to the pkabe of its oebit, but Uranus comes close.

Explanation:

Uranus rtates on an axis that is about 98 degrees away from the line perpendicular to its orbit (https://en.wikipedia.org/wiki/Uranus), compared with about 23 degrees for Earth. So the axis of Uranus is only about eight defeees out of parallel to its orbit.

Earth has long periods of daylight near the poles around the time of their respective summer solstices, and corresponding long periods of darkness around the time of their winter solstices. Uranus with its peculiar axial tilt experiences this alternation over most of the planet and for large portions of its orbital period.