We have added another amazing video to the Star Viewer map. This new video shows the formation of a polar disk galaxy like NGC 4650A.
NGC 4650A is one of only 100 known polar-ring galaxies. Their unusual disk-ring structure is not yet understood fully. One possibility is that polar rings are the remnants of colossal collisions between two galaxies sometime in the distant past, probably at least 1 billion years ago. What is left of one galaxy has become the rotating inner disk of old red stars in the centre. Meanwhile, another smaller galaxy which ventured too close was probably severely damaged or destroyed.
During the collision the gas from the smaller galaxy would have been stripped off and captured by the larger galaxy, forming a new ring of dust, gas, and stars, which orbit around the inner galaxy almost at right angles to the old disk.