We drove the back roads of Puerto Rico from our house in Aguadilla on the northwest coast to the Arecibo observatory the other day, and decided we love everything about this place: the climate, the food, the people, and definitely the scenery. This area of PR is composed of karst limestone, which is ancient sea floor being slowly dissolved by the acidic water flowing through it.
When the erosion occurs from underground water percolation, it can excavate huge underground spaces, leaving cavernous cave rooms.
When the porous limestone roof becomes too thin to support its weight, it collapses, forming a sinkhole, and carrying everything on the surface into the cave system with it. Sinkholes are conspicuous circular depressions, looking like bowls, covered with forest vegetation. One such depression south of the town of Arecibo, P.R. caught the eye of some Cornell scientists back in the 1960s who decIded that the particular sinkhole was the perfect spot to build the world’s largest radio telescope.
Although it was originally designed for research on the earth’s atmosphere, minor alterations in the collector and receiver structures have enabled the largest radio receiver in the world to explore the electromagnetic radiation of the planets of this solar system as well as distant ones in far-off galaxies.
all because there was an underground river carrying acidic water through an ancient sea bed…