Very Large Array (VLA) radio antennas, Socorro, New Mexico, USA. The VLA, part of the National Radio Astronomy Observatory, 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 focusses them onto a receiver. The signals from the 27 antennas are combined electronically. The array is equivalent to a radio dish 36 kilometres across.