How is dark matter distributed (as far as we know)? Let's stay with a single galaxy like the Milky Way. I heard that dark matter is even more concentrated in the center than in the halo, that it is falling off when moving outside, but since the halo is so huge (how huge, ten times larger?) most dark matter can be found there. Is that correct? So there is dark matter also in our solar system. But by what density? If the density would be high, we would have noticed it by the motion of the planets or nearby stars. Can the effect of dark matter only be seen at larger distances where it accumulates despite its low density? thanks!