Althea (9 p.m., UNC-TV) – An American Masters documentary from Durham filmmaker Rex Miller about Althea Gibson, who toiled on the racially segregated tennis circuits of the 1950s and became the first black person to play and win at Wimbledon and Forest Hills – a decade before Arthur Ashe. Read about what inspired Miller to make “Althea.”
Also on tonight . . .
Cold Justice (8 p.m., TNT) – A special episode in which John Walsh interviews the investigative team about their work and gets updates on past cases.
Cold Justice: Sex Crimes (9 p.m., TNT) – In Lake Charles, La., Casey and Alicia must build a case against an uncooperative suspect and try to locate a witness who can confirm the story of a young woman who was raped 23 years ago.
Ancient Aliens (9 p.m., History) – In August 2014, Russian cosmonauts aboard the International Space Station discover living sea plankton covering parts of the windows.