Used By:Rob Kall Added On: 04/11/2016 at 8:00 PM EDT Image Caption: Dark Matter Core Defies Explanation Owner Name / Source: NASA Goddard Photo and Video URL of Owners Page:https://www.flickr.com/people/24662369@N07/ Image Source: FlickrPhotos License:Attribution 2.0 Generic Notes: From CommonsSearch 'dark matter' Search