magma from the planet spinning

Why does Earth and Io have magma? Is it because they both spin at
high speeds compared to other planets and moons? Having a satelite or
being one must warp the surface on the planet or moon which gives us
magma.

wrote:
Why does Earth and Io have magma? Is it because they both spin at
high speeds compared to other planets and moons? Having a satelite or
being one must warp the surface on the planet or moon which gives us
magma.

The melting temperatures inside the Earth come from several
sources. Radioactive decay of the materials the Earth is
made of is one biggie. Heat remaining from the original
accumulation of stuff arriving at high speed is another.
And phase changes (heat of solidification) is another
significant source of heat energy. The Earth may have
gotten a big reheating when a giant impact gouged the Moon
out of its surface.

Though initial accretion heat and radioactivity certainly
have provided some heat to Io, I think the two sources that
are making the largest contribution, today, are tidal
flexing as it orbits in the powerful gravitational field of
Jupiter, and electrical heating by currents through the moon
generated by the moon orbiting inside the magnetosphere of
Jupiter.