SAN JUAN, Puerto Rico (AP) — Giant, aging cables that support one of the world's largest single-dish radio telescopes are slowly unraveling in this U.S. territory, pushing an observatory renowned for its key role in astronomical discoveries to the brink of collapse.

The Arecibo Observatory, which is tethered above a sinkhole in Puerto Rico's lush mountain region, boasts a 1,000-foot-wide (305-meter-wide) dish featured in the Jodie Foster film "Contact" and the James Bond movie "GoldenEye." The dish and a dome suspended above it have been used to track asteroids headed to Earth, conduct researc...