Positioned on hundreds of square miles of desert outside Magdalena, New Mexico, the Very Large Array (VLA) is one of the largest telescopes in the world. Its 27 individual radio antennas, each of which is 82 feet in diameter, form a Y with arms 13 miles long and gather signals from some of the brightest objects in the universe. Its sister project, the Very Long Baseline Array (VLBA), is a line of 10 radio antennas that extends 5,531 miles from Hawaii to the Virgin Islands. The VLA and VLBA create detailed images of celestial objects as close as the moon and as far away as the edge of the observable universe. Scientific Utility Because radio waves can penetrate the cosmic dust that obscures many objects, the VLA and VLBA can see things that optical telescopes can't. Using the VLA, scientists have studied the black hole at the center of the Milky Way, searched for the origins of gamma-ray bursts in faraway nebulae and, in 1989, received radio transmissions from the Voyager 2 satellite as it passed Neptune, giving us the first up-close photos of the gas giant and its moons. The VLBA measures shifts in the Earth's orientation in the universe. By focusing on distant, virtually fixed objectsasuch as quasarsaover time, scientists can detect any apparent changes in Earth's orientation in space. This orientation can be thrown slightly out of place during major earthquakes, like the one that struck Japan earlier this year. What's In It For You Pick a chapter in a modern astronomy textbook, and you will find some material or theory based on data collected by the VLA and VLBA. The VLBA also gathers data on the paths of near-Earth asteroids, which could help scientists predict if one is on a collision course with our planet.