The <a href="https://en.wikipedia.org/wiki/Arecibo_Observatory" id="mwAZo" rel="mw:WikiLink" title="Arecibo Observatory">Arecibo Observatory</a> in <a href="https://en.wikipedia.org/wiki/Arecibo,_Puerto_Rico" id="mwAZs" rel="mw:WikiLink" title="Arecibo, Puerto Rico">Arecibo, Puerto Rico</a>, with the largest <a href="https://en.wikipedia.org/wiki/Arecibo_Telescope" id="mwAZw" rel="mw:WikiLink" title="Arecibo Telescope">radio telescope</a> ever constructed, officially opens.