Portrait of a well known Italian astronomer, physicist and mathematician, supporter of heliocentric theory of the structure of the universe Galileo Galilei (1564–1642. G. Galilei earned fame by the telescope constructed by himself (20 times more powerful than those used before), by discovering four satellites of Jupiter, phases of Venus, Sunspots, mountains of the Moon.
Galileo Galilei‘s (1564–1642) treatise The Starry Messenger (first edition in 1610) announcing revolutionary discoveries in astronomy, including observations of the Moon, stars, Jupiter satellites made by the first telescope created by the author (1609). The treatise includes illustrations of the Sunspots, mountains of the Moon, and four constellations. The treatise was published together with the book Dioptrics, containing main theoretical principles of telescope operation, which was written by a famous German mathematician and astronomer, Johann Kepler (1571–1630) who at the beginning of XVII c. formulated the principal laws of planet movement.
