Videos by witnesses to a large fireball, presumed to be a meteorite, over Chelyabinsk, Russia, show what looks like a missile colliding with it and breaking it up into smaller fragments, and some have speculated it was an extraterrestrial “save” done to protect the human population. Was this a meteorite, and was there an ET defensive measure done?

This is a nice theory but it is wrong on all counts. This was not a meteorite and was not an extraterrestrial save. No extraterrestrials within the earth plane exist, who would have a positive intention to support humanity in any fashion. All are busily undermining humans in every way they can, including the creation of natural disasters of all kinds. They would regard a large meteorite capable of mass destruction as a "lucky break" for them and would enjoy the spectacle because they are sadistic sociopaths who relish the suffering of others they view as lesser than themselves and a potential liability needing to be exterminated.