Three ALMA antennas

Three ALMA antennas linked together as an interferometer for the first time, on the 5,000-meter altitude plateau of Chajnantor. Having three antennas observing in unison makes it possible to correct errors that arise when only two antennas are used, thus paving the way for precise images of the cool Universe at unprecedented resolution. © ALMA (ESO/NAOJ/NRAO)