How did we discover dark matter? Who discovered dark matter? What exactly is the history behind all of this dark stuff? Why is important that we make discoveries about it? Vera Rubin, American astronomer who established the presence of dark matter in galaxies, mea sures spectra in the 1970s. <br /> <br />In 1992, she discovered a galaxy (NGC 4550) in which half the stars in the disk are orbiting in one direction and half in the opposite direction, with both systems intermingled! presence of dark matter was first discovered in 1932 by astronomer Jan Oort, who measured the perpendicular motions of nearby stars relative to the disk of our Milky Way. He studied the gravitational influence of the galactic disk on these stars, and so, was able to measure the mass of the disk. To his surprise, this calculated mass was twice the amount of mass seen as stars and nebulae. A year later, Fritz Zwicky examined the dynamics of clusters of galaxies, and also came to the startling conclusion that the observed galaxies only accounted for 10 percent of the mass needed to gravitationally bind the galaxies in the Coma cluster