The Karl G. Jansky Very Large Array is a radio astronomy observatory located on the Plains of San Agustin, some fifty miles west of Socorro, New Mexico. The Very Large Array has made key observations of black holes and protoplanetary disks around young stars, discovered magnetic filaments and traced complex gas motions at the Milky Way’s center, probed the Universe’s cosmological parameters, and provided new knowledge about the physical mechanisms that produce radio emission.

The observatory consists of 27 independent antennas, each of which has a dish diameter of 82 feet and weighs 209 metric tons. The antennas are arrayed along the three arms of a Y-shape (each of which measures 13 miles long). Using the rail tracks that follow each of these arms—and that, at one point, intersect with U.S. Route 60 at a level crossing—and a specially designed lifting locomotive (“Hein’s Trein”), the antennas can be physically relocated to a number of prepared positions, allowing aperture synthesis interferometry with a maximum baseline of 22 miles: in essence, the array acts as a single antenna with that diameter. The smallest angular resolution that can be reached is about 0.05 arcseconds at a wavelength of 7 mm.