Searching for black holes

At the center of galaxy NGC 1275, some 200 million light years from Earth, there might be a supermassive black hole. In a attempt to map the galaxy and look deep into its heart, an international team of astronomers has linked radio telescopes throughout Europe and America in order to produce a picture of NGC 1275. Jessie Greenstein, the co-discoverer of quasars, and Italian radio astronomer Tiziana Venturi appear.