Astronomy

Mr. Fox 8th Grade Science

Part I: Space like thinking

• Astronomy – the study of the moon, stars, and other objects in space

• Astrology – predicting the future based on the stars. ( they stole this before the scientists could have it. )

Ancient Thoughts

• Geocentric Model – Earth was the center of the universe– 140 A.D. Ptolemy thought that everything

revolved around the Earth– They also believed that we rotated inside a dome

called the celestial sphere and that the universe was perfect and unchanging.

Modern Thoughts

• Copernicus defied the Greek ideas in the 1500s• Heliocentric Model – the Earth and other

planets revolve around the sun. • 100 years later Galileo!!! • Galileo proved Copernicus by charting Venus

and seeing it goes through similar phases as the moon.

• He was arrested by the Church and forced into house arrest for his ideas

Brahe and Kepler

• Brahe – Danish astronomer observed the positions of the planets for 20 years!

• Kepler – German mathematician, took Brahe's work and discovered that each planet has an orbit– Also found that the orbits were ellipses

• Ellipse – an elongated circle, or oval shape.

Newton chimes in

• Newton figured out how everything stays the way it does within space– Please realize that none of these men ever got to

see space for themselves. They weren’t astronauts.

• He concluded, that inertia and gravity keep the planets in orbit.

• HomeworkPage 55 1 – 5 Complete Sentences!