Eric Walker added Arecibo Observatory - Wikipedia to Arecibo Observatory and Arecibo Observatory radio telescope

Eric Walker added Arecibo Observatory and a number of links to Arecibo, and added Arecibo to Puerto Rico

Eric Walker added a number of topics to Observatories, and added Observatories to Telescopes, observatories and telescope networks

Eric Walker added a number of links to Arecibo Observatory radio telescope, and added Arecibo Observatory radio telescope to Arecibo Observatory and Telescopes

Eric Walker added Arecibo Observatory radio telescope and Arecibo Observatory - Wikipedia to Arecibo Observatory, and added Arecibo Observatory to Arecibo and Observatories