Very Large Array (VLA) antennas,with railroad tracks that are used to move the radio telescope dishes to different configurations. The VLA,part of the National Radio Astronomy Observatory (NRAO),consists of 27 radio antennas arranged in a Y-configuration. Each antenna,measuring 25 metres in diameter,is a parabolic dish that collects incoming radio waves and focuses them onto a receiver. The signals from the 27 antennas are combined to make the array equivalent to a radio dish 36 kilometres across. The VLA,opened in 1980,is used to study objects such as radio galaxies,quasars,pulsars,supernova remnants,and gamma ray bursts. Photographed in July 2016,on the Plains of San Agustin,New Mexico,USA |