Everything about The Very Large Array totally explained
The
Very Large Array (
VLA) is a
radio astronomy observatory located on the
Plains of San Augustin, between the towns of
Magdalena and
Datil, some fifty miles (80 km) west of
Socorro,
New Mexico,
USA.
U.S. Route 60 passes through the complex, which is adjacent to the
Boy Scout Double H High Adventure Base. The VLA stands at an altitude of 6970 ft (2124 m) above sea level. It is a component of the
National Radio Astronomy Observatory (NRAO).
Characteristics
The observatory consists of 27 independent
radio antennae, each of which has a dish diameter of 25 meters (82 feet) and weighs 209
metric tonnes (230
Short tons).
The antennas are arrayed along the three arms of a Y-shape (each of which measures 21 km/13 miles long). Using the railroad 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, the antennas can be physically relocated to a number of prepared positions, allowing
aperture synthesis interferometry with a maximum baseline of 36 km (22.3 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.
There are four commonly used configurations, designated A (the largest) through D (the tightest, when all the dishes are within 600 m of the center point). The observatory normally cycles through all the various possible configurations (including several hybrids) every 16 months; the antennas are moved every three to four months. Moves to smaller configurations are done in two stages, first shortening the east and west arms and later shortening the north arm. This allows for a short period of improved imaging of extremely northerly or southerly sources.
The Array Operations Center (AOC) for the VLA is located on the campus of
New Mexico Tech in Socorro. The AOC also currently serves as the control center for the
Very Long Baseline Array (VLBA), a
VLBI array of ten 25-meter dishes located from
Hawaii in the west to the
U.S. Virgin Islands in the east that constitutes the world's largest dedicated, full-time astronomical instrument.
Key science
The VLA is a multi-purpose instrument designed to allow investigations of many astronomical topics. Objects that are commonly studied include
radio galaxies,
quasars,
pulsars,
supernova remnants,
gamma ray bursts, radio-emitting
stars, the
sun and
planets,
astrophysical masers,
black holes, and the
hydrogen gas that comprises a large portion of the
Milky Way galaxy as well as external galaxies. In 1989 the VLA was used to receive
radio communications from the
Voyager 2 spacecraft as it flew by
Neptune.
Past and future
Congressional approval for the VLA project was given in August 1972, and construction began some six months later. The first antenna was put into place in September 1975 and the complex was formally inaugurated in 1980, after a total investment of
USD $78.5 million.
With a view to upgrading the venerable 1970s technology with which the VLA was built, recent funding has been allocated for the conversion of the VLA into the Expanded Very Large Array ("EVLA"). The upgrade will enhance the instrument's sensitivity, frequency range, and resolution, and will install new hardware at the San Augustin site. A second phase of this upgrade to add up to eight additional dishes in other parts of the state of New Mexico, up to 300 km away, is currently unfunded.
Pop culture
The VLA featured prominently in
Carl Sagan's 1980 documentary, and is the setting for the beginning of the 1984 film
2010—with the same scene in the novel, from which the film was adapted, being set at the radio telescope at the
Arecibo Observatory in
Puerto Rico. The 1985 novel
Contact features a fictionalized version of the VLA, expanding the number of dishes to 131 and renaming it to the "Argus Array." For the 1997 film (
Contact), much of the outdoor footage was shot at the VLA site with the number of dishes visible on screen artificially increased by
CGI, and the canyon depicted as being in the vicinity of the VLA is actually
Canyon de Chelly in neighboring
Arizona. It is also seen in the final scene of the alien-invasion film
The Arrival, and the beginning of
Independence Day, when the alien invaders were initially detected by
SETI at the VLA.
New Jersey rock band
Bon Jovi shot the music video for "
Everyday", at the VLA and a "dish" can be seen on the album's cover, named
Bounce . Likewise
Matt Harding can be seen dancing at this location in his second video.
The cover for the
Dire Straits album
On The Night features the VLA.
The VLA features in plans to save the world from satellites being pulled from orbit in the second volume of the comic book series published by
Devil's Due.
The VLA can be visited in
Auto Assault, a
massively multiplayer online game set in post-apocalyptic America.
Visiting
The VLA site is open to visitors year round during daylight hours. A visitor center houses a museum and a gift shop. A self-guided walking tour is available, as the visitor center isn't staffed continuously. Visitors unfamiliar with the area are warned that there's little food onsite, or in the sparsely populated surroundings; those unfamiliar with the high desert are warned that the weather is quite variable, and can remain cold into April.
Further Information
Get more info on 'Very Large Array'.
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