Galileo’s Contradiction: The Astronomer Who Riled the Inquisition Fathered 2 Nuns

From Scientific American:

Galileo-inquisition-daughter_1 The astronomical discoveries made by Galileo Galilei in the 17th century have secured his place in scientific lore, but a lesser known aspect of the Italian astronomer's life is his role as a father.
Galileo had three children out of wedlock with Marina Gamba—two daughters and a son. The two young girls, whether by their illegitimate birth or Galileo's inability to provide a suitable dowry, were deemed unfit for marriage and placed in a convent together for life.

The eldest of Galileo's children was his daughter Virginia, who took the name Suor Maria Celeste in the convent. With Maria Celeste, apparently his most gifted child, Galileo carried on a long correspondence, from which 124 of her letters survive. Author Dava Sobel translated the correspondence from Italian into English, weaving the letters and other historical accounts into the unique portrait Galileo's Daughter: A Historical Memoir of Science, Faith and Love (Walker, 1999).

More here.