Orion over Green Bank.

What will the huge Green Bank Telescope discover tonight? Pictured, the Robert C. Byrd Green Bank Telescope (GBT) on the lower right is the largest fully-pointable single-dish radio telescope in the world. With a central dish larger than a football field, the GBT is nestled in the hills of West Virginia , USA in a radio quiet zone where the use of cell phones, WiFi emitters, and even microwave ovens are limited. The GBT explores our universe not only during the night -- but during the day, too, since the daytime sky is typically dark in radio waves . Taken in late January, the featured image was planned for months to get the setting location of Orion just right. The image is a composite of a foreground shot taken over a kilometer away from the GBT , and a background shot built up of long exposures during the previous night. The deep background image of Orion is fitting because the GBT is famous for, among many discoveries , mapping the unusual magnetic field in the Orion Molecular Cloud Complex .