There are several types of evidence for DM and Helsinki scientist Matts Roos provides a 39 page overview listing and summarizing each kind. It's a useful article. He gives graphic figures to illustrate each type of evidence. http://arxiv.org/abs/1208.3662 Astrophysical and cosmological probes of dark matter Matts Roos (Submitted on 17 Aug 2012) Dark matter has been introduced to explain mass deficits noted at different astronomical scales, in galaxies, groups of galaxies, clusters, superclusters and even across the full horizon. Dark matter makes itself felt only through its gravitational effects. This review summarizes phenomenologically all the astrophysical and cosmological probes that have been used to give evidence for its existence. 39 pages, 24 figures. Accepted by J. of Modern Physics and will be released as Special Issue in September, 2012 The Bullet Cluster evidence, that everybody seems to know about, comes on page 28. People new to the subject of DM might benefit by at least leafing thru and glancing at the pictures. This review paper only covers the astrophysical and cosmological evidence. There are also several ongoing efforts to detect DM particles. Results from that work are preliminary and controversial--and were outside the scope of Roos's review.