In the movie Contact, Jodi Foster plays an ambitious astronomer that made it her goal to find life elsewhere in our vast universe. I believe the line she muttered as an 11yr old was “I’m going to need a bigger telescope.” The scene directly after that line was the reveal of Arecibo Observatory, a radio telescope in Arecibo, Puerto Rico and the start of Jodi’s romance with Matthew McConaughey. Indeed she had found herself a bigger telescope. In fact it is the largest radio telescope in the world. The main dish measures 1,000ft in diameter and is situated in a sink hole. That is actually why this particular spot was chosen. It also helped that Puerto Rico is the closest location in the US to the equator. The sink hole, more specifically a karst sinkhole, was almost a perfect fit for the curvature of the dish. The dish is a combination of 38,778 perforated aluminum panels supported by a mesh of steel cables. They can manipulate the networked panels to focus in on a particular location. The large track system, to which the dome is connected, can line up in conjunction with the dish to a point in space to detect radio waves. The telescope can receive radio waves that are emitted from pulsars and even quasars and galaxies. That’s a long ways away. We are talking 100 million light years. The dome, called the gregorian dome, receives the signals from outer space and also receives signals that are emitted from their own antennas. That would be the long rod pointing directly towards the dish. The radio signal is sent out into space and bounces back off an object (i.e. satellites, planets, etc..) and those waves are analyzed and can reveal a ton of data. Just like sonar but with radio waves.
My wife and I visited the observatory last month while on vacation. It’s a good drive from San Juan, with some really sketchy roads, but well worth it.
I only skimmed the surface here so jump over to their website for more info, www.naic.edu.