The Very Large Array (VLA) is part of the National Radio Astronomy Observatory. The VLA consist of 27 radio antennas that  work together arranged in three arms. It was completed in 1982 (after eight years of construction), so  I was there for its 20th anniversary.

Although two movies are shown in  the VLA Visitor Center, apparently microwaved popcorn is not allowed.

In the museum, an exhibit showed how sometimes the VLA can be used in conjunction with several other radio telescopes to form the Very Long Baseline Array (VLBA). The combined system " is sharp enough to read a newspaper in New York from the distance of Los Angeles."

After sitting through two movies and walking through the museum, it was finally time to see a radio telescope up close. Watch out for snakes!

Contrary to popular belief and Hollywood movies (such as " Contact" ), the VLA telescopes were never used to " listen" for extraterrestrial intelligence (although other radio telescopes can be used for that purpose). Radio waves are simply another part of the spectrum outside the visible range, like ultraviolet or infrared. They are gathered the same way a traditional telescope gathers visible light. The telescopes " see" at one of seven radio wavelengths (ranging from 91 to 0.7 centimeters), and the Control Building combines data into computer-generated  visual images.

The antenna featured on the tour was number 22. Each  antenna weighs 235 tons, with the movable reflector (the dish) weighing 100 tons.

Just one antenna is an impressive sight, but it works with 26 others to produce images. Using computerized techniques, their 82-foot diameter dishes  together deliver the same results  as if they were one gigantic 17-mile diameter dish! Needless to say, the array provides much more flexibility than a single dish, too.