The Milky Way is a cloud of space dust and debris from planets and stars

This is true to an extent. The Milky Way is a galaxy. A galaxy contains stars, planets, space dust, and some other things. A galaxy is not necessarily, completely made from a cloud of space dust and debris. There are other things that make a galaxy a galaxy.

Explanation:

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.