Text this: The planets / "Venus unveiled" is a WGBH Boston/BBC TV Coproduction for Nova ; produced by Bettina Lerner. "Magnetic storm" is a DOX production for NOVA/WGBH and Channel 4 ; written and produced by David Sington ; directed by Duncan Copp. "MARS dead or alive" and Welcome to Mars" are a NOVA production for MDTV Productions for WGBH/Boston in association with National Geographic Channel International ; written and directed by Mark Davis.