Dark Matter is a type of substance made of particles that are able to attract objects to themselves through gravity, when they are added up in bulk. In this arena, it acts in the same way that the Sun does when it attracts the planets. But, unlike the Sun, it does not shine. As far as we can tell this type of matter gives off no electromagnetic radiation at all, hence we call it “dark”. We know it exists because we can track its gravitational pull in our own Galaxy and in distant galaxies, but we still don’t know what type of substance it is.
