Question: What are the properties of dark matter?

Katherine Haxton answered on 18 Mar 2012:

Scientists think that dark matter makes up just over 80% of the mass of the universe but it’s currently just a theory. It’s called dark matter because the theory says that it will not emit or absorb electromagnetic radiation. As emitting or absorbing electromagnetic radiation like light is one of the main ways we have of investigating matter, it’s quite difficult to prove it! Scientists have some experimental data that seem to confirm the existence of dark matter, or that only make sense if dark matter is the reason. No one has actually collected a sample yet so the properties are only theories.