Closeup of the feed antenna of the <b>Arecibo Radio Telescope</b>, at Arecibo, Puerto Rico.  The dish reflector of the telescope is built into a valley in the landscape, and the feed antenna is suspended by cables above it.  Since the reflector can't be moved, the telescope is steered to point at different regions of the sky by moving the feed antenna <i>(in bell shaped dome)</i> along on a curving track.  The dome shields the feed antenna from interfering radio signals.
Alessandro Cai (<a href="//commons.wikimedia.org/wiki/User:OliverZena" title="User:OliverZena">OliverZena</a>)
Taken in January 2006
<a rel="nofollow" class="external text" href="http://oliverzena.altervista.org/ita/frm_off/foto/eve&amp;via/2006/zoom_pr_frm_off.html">own work</a>