Until the tragic collapse of its dish in August 2020, the Arecibo Observatory was the largest operational radio-radar telescope in the world. Conceived in the late 50s as a military communications experiment, the facility segued into becoming a planetary radar, a super sensitive radio telescope, an upper atmospheric probe and notoriously, a seeker of extra-terrestrial intelligent signals. Learn the history and some of the findings in those areas of research, which began in a sinkhole of rural Puerto Rico.
