The Vey Large Array is one of the world’s premier astronomical radio observatories, consisting of 27 radio antennas in a Y-shaped configuration on the Plains of San Agustin fifty miles west of Socorro, New Mexico.
Each antenna is 25 meters in diameter. The data from the antennas is combined electronically to give the resolution of an antenna 36km across.
The Very Large Array has become a destination for people like us who loves traveling a lonely scenic byway and those interested in sci-fi movies. You would instantly recognize the Very Large Array from movies such as Contact, Independence Day and Terminator Salvation. And Bon Jovi even shot a music video here.
Some people says that the giant antennas in the Very Large Array are part of SETI (Search for Extra-Terrestial Intelligence), bu they are not. The dished only listens to the intergalactic noicemakers such as black hole and pulsars, but of course who knows of one day someone from a distant gallaxy will say hello to planet Earth, probably the antenas would record it too.
Upon arriving at the VLA, a visitor center welcomed us with some exhibits about research being done at the facility a short video, then take a self-guided walking tour around the facility. Of course, not the entire facility is open to the public. You can’t walk around to the other antennas.
The Bracewell Radio Sundial, named for Ronald Bracewell, a pioneer in radio astronomy, it the only sundial of its kind in the world. The central portion of the sundial is on a 46-by-35-foot concrete slab. Markers that indicate the time of day are embedded in the slab, where the shadow of a metal sphere mounted atop a post can fall on them. Visitors can walk around the sundial to find not only the time of day but the approximate time of the year. Other markers indicate important dates in the history of radio astronomy, and solar noon at other observatories.
To help visitors better understand how the antennae work, there installed two parabolic dishes or the Whisper Dishes, so visitors can better understand the VLA’s ability to amplify the signals which bounce off the focus on the telescope’s antennae. These dishes are set about 30 feet apart. We each stood at one of the dishes while one of us speak softly into one of the dish, while the other one listens. Our words were transmitted with crystal clarity. It was as if we were standing right next to each other.
These little dished bounces the sound wave from several feet away and focus them into the ear. Similarly, each 82foot wide dish of the VLA bounces the very faint radio waves from far out in space and focuses them in its receivers.
Our last stop on the tour was the service yard. Each dish is rotated out of service for maintenance on a regular basis. This is where the dishes are maintained in the safety of a huge repair hangar.
See more at: http://www.vla.nrao.edu/