The position of the Great Attractor was finally worked out in 1986. It is between 150 and 250 million light years (47–79 million parsecs) away. Objects in that direction lie in the Zone of Avoidance, which is the part of the night sky obscured by the Milky Way galaxy. Because of this, they are difficult to study with visible light. However, X-ray observations have revealed that the region of space is dominated by the Norma Cluster, a massive cluster of galaxies, with large, old galaxies, many of which are colliding with their neighbours, and/or radiating large amounts of radio waves.