Galileo was born in 1564 in Italy. He became a an astronomer, physicist and mathematician. Back in 1600s he was not popular. The Catholic church believed that the moon was smooth but with his telescope, Galileo observed that it was covered in craters and mountains. The Catholic church also believed that the sun was smooth, but he observed that the sun was covered in dark areas called sunspots. He also realised that the sun was rotating. Galileo also disagreed with the old belief that the Earth was at the centre of the Solar System. Instead, he believed that the sun was at centre of the Solar System, and it was orbited by the Earth and other planets. In 1633, the church put him under house arrest for nine years so he will not share his observations. He spent much of these years researching and wrote his most famous work called 'Two New Sciences'. He died in 1642 when he was still under house arrest. Today he is viewed as the father of modern Science.