WASHINGTON (AFP) – A pair of NASA probes wandering in deep space discovered that the outer edge of the solar system contains curious magnetic bubbles and is not smooth as previously thought, astronomers said Thursday. The NASA Voyager twin spacecraft, which launched in 1977, are currently exploring the furthest outlays of the heliosphere, where solar wind is slowed and warped by pressure from other forces in the galaxy, the US space agency said. "Because the sun spins, its magnetic field becomes twisted and wrinkled, a bit like a ballerina's skirt," said astronomer Merav Opher of Boston University. "Far, far away...