The above image is a computer simulation of the distribution of mass in a Dark Matter dominated Universe. ... Structure (\eg density enhancements) clearly forms at the intersection of these filaments. ... What is Dark Matter? ... Testing for the presence of dark matter in the solar neighborhood now becomes an accounting problem The possible sources of this mass in the solar neighborhood are 1) luminous stars, 2) interstellar gas, 3) stellar remnants (mostly white dwarfs) and 4) dark matter: . ...