This study advances the scientific program of Copernicus, Kepler, and Newton into the realm of tectonic processes. A generalization of Euler's rigid-body rotation theory to the case of an arbitrarily deformable spheroid is obtained. The generalized Copernican problem is solved: from the decomposition of motions into four elementary rotations to finding their compositions that describe complex trajectories of points on the Earth's surface. By analogy with Kepler's laws, the First Law of Tectonic Motion is established—a fundamental invariant of motion on a deformable spheroid asserting the preservation of conformal structure: the trajectories of tectonic motion are orbits of the Möbius group action. This approach creates a unified kinematic model linking astronomical variations in Earth's rotation with tectonic deformations, without invoking any hypotheses about the planet's internal structure.