Non Luminous Matter

Just like in any other science, there are two ways to detect an object. One is by observing it directly, and the other is by observing the effects that it has on another or more easily observable objects.

We all know that there is a lot of matter in the night sky that we cannot directly see. When instruments such as, telescopes, or even radio telescopes, are used, one can only see objects which emit light or radio waves. Not everything in the universe does this. Just like our earth. We wouldn't be able to see planets like our own, because they would be too dim to see.

If one was to add up all the mass of all the planets in our solar system, it would be significantly less than one percent of the Sun's mass. As a result of this- non-luminous matter - it never caused great concern. At least for the time being.