Is there any credible hard evidence that this equivalence extends to all moving bodies? We accept on good grounds that the apparent mass of moving objects is enhanced by motion, to a measurable degree that increases indefinitely as observed speeds of relative motion approach c. Likewise, a spinning object acquires extra mass/energy from its motion. Examples are the rotating planet Jupiter, and spinning neutron stars. Is such a body's universal gravitational attraction for, say, its orbiting satellites and other things ponderable enhanced by the mass-equivalence of the body's rotational kinetic energy, so affecting the orbital periods of satellites, for instance? Do we by now just take as a matter of faith that the equivalence of gravitational and inertial mass always prevails? That the mass-energy of moving stuff gravitates exactly as does what we deem to be 'familiar static' massive stuff, e.g. lumps of iron or even herds of lumbering elephants? Or is it a consequence of unassailable logic that I've missed? or just of using Occam's razor?