Voyagers (Ben Bova)

Ex-astronaut turned physicist Keith Stoner knew that the fiery object hurtling toward the Earth was an alien spacecraft—but the world might never know. He was trapped in an iron cordon of secrecy, for the discovery had set off a brutal power struggle among the elite, raging from the sacred halls of the Vatican to the corridors of the Kremlin and the Pentagon. Each nation wanted to be the first to contact the aliens, to learn their superior