The Explanans and Planandu A, the Explanandum

Scientific explanation consists of two things. You cite some initial conditions, and then you cite a law of nature. This is why it's called a deductive nomological model. If we were explaining the position of mars, we might cite where mars was a week ago plus some of newton's laws motion,. Or something samd laws about gravity. Unless they've given those initial conditions plus these laws, you can see why mars has the position that it does now. That's sort of what newton did that made him so famous. And i don't know if that's equivalent to, but am? I think a rough guide is just contingency. Anything that's contingent probably calls out