WORLD HISTORY

Detailed explanation-1: -Galileo Galilei (1564-1642) was part of a small group of astronomers who turned telescopes towards the heavens. After hearing about the “Danish perspective glass” in 1609, Galileo constructed his own telescope. He subsequently demonstrated the telescope in Venice.

Detailed explanation-2: -He soon made his first astronomical discovery. At the time, most scientists believed that the Moon was a smooth sphere, but Galileo discovered that the Moon has mountains, pits, and other features, just like the Earth.

Detailed explanation-3: -Peering through his newly-improved 20-power homemade telescope at the planet Jupiter on Jan. 7, 1610, Italian astronomer Galileo Galilei noticed three other points of light near the planet, at first believing them to be distant stars.

Detailed explanation-4: -In 1609, he learned of the spyglass and began to experiment with telescope-making, grinding and polishing his own lenses. His telescope allowed him to see with a magnification of eight or nine times, making it possible to see that the Moon had mountains and that Jupiter had satellites.