Over the last 10 years a large number of iceballs have been found in the outer solar system out beyond pluto

The statement is true. Lots of ice balls, ice small planets and planetoids have been discovered in the outer Solar System beyond Pluto. This has lead to confusion in the classification of the planets, and what is and what is not a planet, so Pluto was first taken out from the planets order, than brought back, and there's a big debate and there's not really an opinion that prevails by much over the other, on weather Pluto should be or not a planet, and the same goes about the other planets and planetoids, like Charon and Xena for example.

Geothermic gradient is the rate of increasing temperature with respect to increasing the depth in the earths interior. away from tech tonic plates boundaries, it is about 25-40 c/km (72-87 degrees f/mi) of depth near the surface in most of the world.