Arecibo: The Largest Telescope . ... Credit Copyright: National Astronomy and Ionosphere Center , Cornell U. , NSF Explanation: The Arecibo radio telescope is currently the largest single-dish telescope in the world. ... The Arecibo telescope has been used for many astronomical research projects , including searches and studies of pulsars , and mapping atomic and molecular gas in the Galaxy and the universe . ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ...