This video starts with data from a survey of galaxies (blue and green) done by ESA’s Herschel Space Observatory and zooms in on a source that astronomers found interesting. The zooming in continues using observations performed with the Atacama Pathfinder Experiment (APEX; red). Finally, the video shows further observations obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) at higher resolution. Those observations revealed that the interesting source isn’t an ancient, massive galaxy, but of a pair of distinct massive galaxies about to merge. These two galaxies, each roughly as massive as our Milky Way, were informally dubbed the ‘Horse’ and the ‘Dragon’.
Video Credit: ESA