The VLA

These are just a few pictures of the VLA taken in late July, 2000.  The VLA is about 50 miles due west of Socorro, New Mexico.  It is on an enormous flat plain (the Plains of San Augustin) at an elevation of 2124 m (6970 ft).  Its visual appeal has resulted in it being featured in several motion pictures, most notably "Contact" and "2010 - A Space Odyssey".

Unlike its role in "Contact", however, the VLA is not used for SETI (Search for ExtraTerrestrial Intelligence) research (although Arecibo in Puerto Rico is, as it was shown in the same movie).  This is primarily because the frequencies and resolutions of its design aren't in the "sweet spots" used for SETI and in fact, would not be optimal for such research.  It is especially good at looking at BIG structures in our universe, such as other galaxies, or even stars, as well as other regions that would be generating radio signals as a consequence of various physical interactions in our universe.

The VLA is a radio telescope, which means that it observes in the radio frequency portion of the electromagnetic spectrum, just as an optical telescope works in the visual portion of the same spectrum.  It is different some other telescopes in that it uses an "array" of smaller telescopes (if you could call them that!) working together to create a much larger virtual telescope.  This same approach has since been used successfully with many other radio and optical telescopes as a much more cost effective way of creating large, high resolution observing instruments.

The VLA consists of 27 dish antennas that are 95 feet high, have a diameter of 25 meters (82 ft), and weigh 230 tons each.  They are transported over a "Y" shaped configuration of double train tracks by a 100 ton transport/crane that is specially designed to move them while keeping their electronics active (their sensory electronics are cooled by liquid nitrogen and must stay on at all times to remain properly calibrated and balanced).  The radius of two of the legs of the "Y" is 11 miles while the third is 13 miles, creating a virtual dish over 22 miles (36km) in diameter.  There are actually 28 dishes in the total inventory, with a rotation schedule to the maintenance facility that lets all dishes be serviced every 3 years.  The VLA can observe at various bands between 74 and 50,000 MHz (400 to 0.7 cm).

These pictures were taken while the array was in its close configuration (the "D" configuration which gives a maximum separation of 1 km) , so most of the dishes could be captured in the pictures.  Even in the close configuration, the distance between the outer dishes is very significant, which is something to keep in mind as you look at these photos.

For more information about the VLA, go to their homepage at:

http://zia.aoc.nrao.edu/doc/vla/html/VLAhome.shtml

This is at the entrance, you can see some of the dishes in the background... they are still anywhere from 1 to 3 miles away in this picture.

This is on a service road within the compound, just outside of the main building.  This view shows all three "arms" of the dishes with the center of the array right behind my hat.

Another view of the array from a distance.  I think that this one was taken right by the maintenance facility.  There is a set of rails to the right of this photo where the transport crane takes the dishes to the maintenance building.

This is the maintenance building with a crane in the near foreground (as near as I could get it and still keep it in the picture).  The antenna dish in this picture is about 50 meters or more behind the fence.  You can see my vehicle in the foreground even with the 100 ton crane. You may also notice a Chevrolet Suburban in the building with the dish, just to give you a comparison of size.

This is not a great picture insofar as its composition goes, but it does give some perspective as to the enormous breadth of the VLA.  You will notice a series of white "dots" on the horizon, which are, of course, the antennas.  Red Rover (my car) is in the foreground.  This was taken about 10 or 11 miles away from the VLA and it was quite visible at this distance.  The whole plain that the VLA is upon is at an altitude of 2124 m (6970 ft), which is unusually high for such an expanse of land.

A side note:  When we were at the VLA, we were fortunate enough to have a private guided tour of the facility.  The two graduate students who were on fellowship at the VLA were studying some of the things that are typical of the areas of science, astronomy, and cosmology that you would expect at the VLA.  One young man was involved in a study of mass distribution in the universe, while the other student, a young woman, was tracking gamma-ray bursters and their origins.  We really appreciated the tour and the opportunity to see some of the areas of the facility that we might not otherwise have seen.