Giant in the Cage
At the Green Bank Telescope, astronomers can choose a variety of receivers to use to observe the radio skies. One of them can only fit up at the prime focus of the telescope. The cone at the left is the funnel entry into the feed of the receiver which is enclosed in a cage suspended on the end of the GBT’s 200-foot feed arms. It receives the radio waves bounced up here by the 100-meter dish of the telescope below.