Galileo Galilei (1564-1642) was an Italian astronomer, physicist, and mathematician who is considered one of the most important figures in the history of science. He is known for his improvements to the telescope, which allowed him to observe and study the stars, planets, and moons in the solar system. He is also known for his support of the Copernican model of the solar system, which placed the sun at the center of the solar system, rather than the Earth. This went against the dominant Aristotelian view of the time, which was supported by the Catholic Church, and led to Galileo being put on trial for heresy. Despite this, his work laid the foundation for modern astronomy and the scientific method.