Question: do you know anything about the newly discovered "dark matter"?

Evan Keane answered on 21 Jun 2011:

Hi 08mhook. Well I know about as much as anybody, which is not much!! Astronomers don’t know what dark matter is. But they know it exists in some way. Why? Well, you can observe galaxies and see how they move and if you do that you quickly find that there is more stuff in them than we can see any light from. We see a gravitational effect (so it must be “matter”) but we see no light from it (so we call it “dark”). It might not be “dark” but maybe just very very faint. For example, maybe it is a load of rocky things which are too small to see, or “brown dwarfs” (these are failed stars which never manages to start nuclear fusion because they are too small), or maybe it is some kind of material we have never encountered before. This is all we know now – we have more questions than answers.