I typed slapdash things into Wolfram Alfa just to get a sense of the kinetic energy of something like a 100km metal sphere buzzing as at 40 km/s (it's a screaming chonker of an overestimate but hey) and got something like a millionth of total yearly solar output or 1/5th of lunar kinetic energy (orbiting earth). As D. Wooderson famously said, we're talkin' some fuckin' muscle, to ride such a thing. If you have it, you might even be better off just taking the moon instead.