GEOL 003 Lecture 2: Chapter 2_ Earth in Space
Document Summary
Why is it warmer in summer and colder in winter? (how does earth"s position relative to the sun control the climate?) Ancient civilizations interpreted rising of sun in east and setting in west to indicate the sun (and other planets) revolved around earth. Remained dominant idea for more than 2,000 years. Heliocentric orbit hypothesis: 16th century idea suggested by. Confirmed by galileo"s early 17th century observations of the. Galileo used early telescopes to observe changes in the size and shape of venus as it revolves around the sun. Earth , a small ,rocky, planet orbits the sun a medium sized star, one of billions of. Size of the universe: luminosity stars in the milky way galaxy , one of billions of galaxies in the universe. Brightness of pulsating stars - cepheid variables was used to determine the distance from earth. Repeated measurements determined cepheid variables were moving away from earth.
