Galileo Galilei is famous for many things: for his science (Einstein called him the "father of modern physics"); for his flamboyant style (he wrote in Italian not Latin, enlivened texts with rough humour, argued loudly in staged debates) and for his harsh treatment by the Catholic Church. What's less well known are the details of his private life--a life that, as Dava Sobel points out in Galileo's Daughter, was just as complex as the scientist's public life. Galileo had three illegitimate children; the book's title refers to the oldest, Virginia, later Suor Maria Celeste (she took the name in acknowledgement of her father's fascination with the stars). Unable to marry because of her illegitimate status, Virginia entered a convent at 13 and maintained a lifelong correspondence with her father. Sobel has translated Virginia's surviving letters for the first time and, combining those letters, commentary, and gorgeous illustrations, she sets out in Galileo's Daughter to illuminate a different side of Galileo, the father deeply committed to his daughter and to her faith. Virginia's letters are tender, witty and intelligent. They are crammed with details of day-to-day life in Florence: "The broad beans are set out to dry and their stalks fed for breakfast to the little mule, who has become so haughty that she refuses to carry anyone." Sobel's commentaries brilliantly help to put into contextual the letters. "Most of Suor Maria Celeste's l