"It is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring." ~ Dr. Carl Sagan[7]
From what we just investigated, the only thing we can say for sure is that dark matter has mass. In fact, that right now is the only thing the wider astronomical community can say that dark matter has. However, there is growing evidence that dark matter is not any sort of normal matter.
The best thing I can do now is direct you to better resources than myself if you are still curious about dark matter. The below list is by no means comprehensive, but it is a very good place to start.
The Chandra X-ray Observatory has put together a very good website about dark matter aimed at the general public. It briefly goes into a few different kinds of evidence for dark matter, as well as a general discussion of what dark matter is.
Astronomy Picture of the Day, or APOD, is another website aimed at the general public that has a ton of interesting information. Everyday a new picture is posted with a description written by a professional astronomer. Key words and ideas are linked to other websites going into more detail about that particular topic. Often this is a great place to start with any astronomy question.
NOVA scienceNOW put together this -- a short video about dark matter in the 'bullet cluster'.
If your looking for scientific articles here are a couple good places to start:
If you are curious about how Rubin and Clemens took their data, I have provided some information here:
The references I used to compile this website can be found here: