Read about the astounding discovery by Italian scientist Galileo that our moon is not the only moon in the heavens! In this exciting book, Galileo recounts how in 1610 he used a telescope, a new Dutch invention, to determine that the planet Jupiter has not just one but four moons.

About the author

Galileo, who lived from 1564 to 1642, was an Italian astronomer and physicist. He made the first effective use of the refracting telescope to discover important new facts about astronomy. He also discovered the law of falling bodies as well as the law of the pendulum. In addition to inventing a variety of scientific instruments, he developed and improved the refracting telescope, though he did not invent it.

Galileo was twice censured by the Roman Catholic Church for defending Copernicus' theory that the earth and all the planets revolve around the sun. In 1633, the church forced Galileo to recant (publicly withdraw) his work and sentenced him to life imprisonment.

Because of Galileo's advanced age and poor health, the church allowed him to serve his imprisonment under house arrest in a villa outside Florence. There, he passed the remainder of his years in relative isolation, eventually becoming blind. But he managed to complete his second scientific masterpiece, the Discourse on Two New Sciences, published in 1638. In this work, Galileo provided both a mathematical proof of his new theory of motion and an original study of the tensile strength of materials.