The Very Large Array (VLA) — Listening to the Stars in New Mexico

Today, this vast, arid desert valley is now home to the most powerful radio telescope in the world, the Very Large Array. With its twenty-seven dish antennas, each connected to the other, spread out over 22 miles in a “Y” formation, the Very Large Array, or VLA, is capable of detecting extremely faint radio emissions from the distant stars.

How does it work? Within the electromagnetic spectrum, there are six wavelengths:  Gamma rays, X-rays, Ultraviolet, Visible, Infrared and Radio. Unlike their optical counterparts who use conventional telescopes with glass lenses which gather light within the visible spectrum to form an image, the radio astronomer utilizes a dish-shaped radio antenna to receive radio waves from stars, planets, galaxies and other celestial objects. As each antenna receives a signal, they are in turn sent to a computer where they are combined and processed into one large radio image. After the signals are processed, the image is then recorded onto magnetic tape to be viewed and analyzed by astronomers.

Twenty-seven dish antennas dot the flat desert landscape
Photo by Carla DeMarco

From its dedication in 1981 to the present day, the Very Large Array has become an indispensable astronomical tool for astronomers and other scientists worldwide who apply each year for observing time. In only a short time and with the aid of advancing technology, the VLA has significantly contributed to the studies of stellar and galaxy formation, black hole phenomena, and the search for extra-solar planets. In 1989, history was made at the VLA as scientists and the public were treated to spectacular photos of Neptune and its moons, transmitted from nearly three billion miles away by the Voyager 2 spacecraft. The photos revealed what scientists later dubbed “the Great Dark Spot,” a storm rotating in Neptune’s atmosphere similar to that of Jupiter’s Great Red Spot. In August 1998, the VLA produced a detailed radio map of the heavens in conjunction with an earlier observation made in optical wavelengths conducted by New Mexico’s Apache Point Observatory in the Sacramento mountains.

For more information, visitors may write the National Radio Astronomy Observatory Public Information Office at P.O. Box O, Socorro, New Mexico, 87801, or access the VLA web site .