I went to a cosmology seminar recently. It was mostly for fun, but if you complete a take home exam you get a tiny bit of college credit for it. Things were going along fine until I ran across the last two questions: How was Dark Matter just discovered and when did this happen? What measurement in 2003 confirmed the Dark Matter evidence? I can't find any specific references to this in my notes about Dark Matter actually being discovered other than some information about ongoing experiments for detection being done with liquid xenon. The lecturer was very good but he was way over my head technically. Could anyone point me to some web links where I can research these questions more? I am turning up zilch on my web searches and I would really like to take a stab at answering them. Thanks!