To look at the Russian RadioAstron spacecraft, which launched from Kazakhstan this Monday, it doesn't seem particularly record-breaking. Its 10-meter (33-foot) antenna is certainly no match for those on earthbound radio telescopes, which can be up to 300 meters (984 feet) across. Once in orbit, however, its signal will join forces with those from ground-based telescopes to form one giant virtual telescope. Using a process known as interferometry, they will form the equivalent of a single radio telescope dish that at over 350,000 kilometers (217,480 miles) across is almost 30 times wider than the Earth. Although it's not actually one physical object, it is nonetheless being heralded as the largest telescope ever created.
