Man went to the Moon, but the origin of a cat’s purr remains a mystery?

I know it is said that how a cat purrs is not completely known. I know it is in the throat, when my cat purrs that is where she seems to create it. When CK, my Tom, was a kitten he would start purring the moment a finger touched his back, don’t know if that was nervousness or contentment, he doesn’t do it as easy after surviving a dog attack. How can scientist not know? They seem to be so sure of other traits and feelings animals have but can’t figure out something as mechanical as purring? By the feel of it seems like a controlled waking snore. If science can send man to the moon and back, they should be able to figure out how a cat generates purring.