Correspondent Laura Ling explores the growing controversial practice of birth tourism, in which foreign mothers travel to Southern California to deliver children who are U.S. citizens.Then, Madeleine Brand interviews Lucy Jones, seismologist with the U.S. Geological Survey, on the earthquake early detection system and its effectiveness in sensing the state's most recent temblor. Also, in the wake of a meteor crash landing in Russia last month, CNN's Chris Lawrence reports on discussions between Congress and America?s top scientists about how to anticipate future threats from space.
