Strange result after mapping height map to sphere

I've been using some height maps on a sphere to test out some details for created procedural planets, and all of my height maps returned a sphere that simply had lines, horizontal "mountains" across the entire shpere, and no real detail. Eventually I tried using a height map which was just a diagonal from top left to bottom right. The resulting sphere did not in any way emulate the hightmap, but formed lines once again. the attached image shows the lines, and the texture is a ramp which bases the height of the terrain scale into a color what is preculiar is the texture does not fit accordingly to the sphere, and repeats, instead of just one diagonal across the sphere.

Why is the sphere reacting this way?

Picture of the planet, and the strange result of mapping:

Height map used:

The result of the texture, according to the heightmap: