Astronomy DSST History Exam Questions and Answers

Geocentric the model of the solar system that the Greeks believed in, where the Earth was at its center.All of the plantes in the solar system revolved around the Earth. Heliocentric the model of the solar system where the Earth and other planets revolve around the sun Aristotle The Greek astronomer who believed that the universe was finite and dome shaped. Ptolemy, Cladius The Greek astronomber who believed the planets moved in orbits (little circles on bigger circles). He based his study of astronomy on the belief that Earth was at the center of the universe. For 1500 years, Ptolemy's Earth-centered theory remained the popular theory for the structure of the universe. Copernicus, Nicolaus Called "the founder of modern astronomy".Proposed the heliocentric model in 1543. Copernicus thought that the planets orbit the sun and that the sun was the center of the universe. Copernicus thought the stars must be very far away because they never shifted their relative positions. Copernicus create sun-centered model of solar system designed to replace Ptolemaic model, but it was no more accurate because he still used perfect circles. Galilei, Galileo First person to use a telescope to study the heavens and found evidence that supported the heliocentric model. Galileo Galilei is often referred to as the 'father of modern observational astronomy'. The Galilean telescope 1609 was the first telescope used to observe the heavens. Galileo claimed to have seen four moons orbiting Jupiter, mountains on the Moon, phases like that of the moon on Venus in a way that proved it must orbit the sun and not Earth, and found evidence to prove that the Milky Way was made up of tiny stars. Brahe, Tycho Provided observations used by Kepler to refine the model by introducing elliptical orbits. His accurate astronomical observations formed the basis for Johannes Kepler's laws of planetary motion. He showed in 1577 that comets were not part of our atmosphere and were much further away than our Moon by use of the parallax effect. Brahe used mural quadrant to measure the positions of the planets and stars.