Following his trial, Galileo was initially placed under house arrest at the residence of Archbishop Ascanio Piccolomini in Siena. He was later allowed to move to his villa in Arcetri, near Florence, where he remained under house arrest for the rest of his life.

Galileo suffered a personal loss with the death of his beloved daughter, Sister Maria Celeste, who had provided him with emotional support and assistance throughout his life. She maintained detailed records of their correspondence, which give invaluable insight into Galileo's life during house arrest.

Despite his house arrest, Galileo continued his scientific work and published "Two New Sciences", a treatise summarizing his lifelong studies on motion, mechanics, and the strength of materials. This work was published in Leiden (Netherlands), as his previous publisher in Florence was too scared to publish his works. It is considered one of his most important contributions to physics.

Galileo's eyesight deteriorated significantly, and he eventually became completely blind. This hampered his ability to conduct further astronomical observations, but he continued to work with assistants.

Galileo Galilei died at his villa in Arcetri, at the age of 77. Despite his contributions to science, the Church forbade a public funeral and burial in the family tomb. He was initially buried in an unmarked room in the Basilica di Santa Croce.