The Arecibo Ionospheric Observatory is one of the world's largest radio telescopes located in Arecibo, Puerto Rico. American scientists built it into a meteorite crate. It is an important data source for the SETI project.
In late 1994 Fox Mulder investigated reports that the observatory was receiving transmissions from an extraterrestrial sources. (TXF: "Little Green Men").
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The Arecibo Observatory exists in real life and is a common filming location due to its spectacular architecture.