COPY TOPIC 3 Movements of the Planets 2 Theories of Solar System 4.6 Billion Years old • Geocentric –“EarthCentered” –Claudius Ptolemy –90 A.D. • Heliocentric COPY –“SunCentered” –Copernicus –1543 Claudius Ptolemy Nicholas Copernicus •1473--1543 GEOCENTRIC HELIOCENTRIC •Better explains retrograde(backwards) motion, relative brightness and positions of planets Slide 8 of 35 TYCO BRAHE • Danish Astronomer • 1546------1601 • Built first observatory in history(Europe) • Collected data on positions of the planets(Studied Mercury/Venus) JOHANNES KEPLER • 1571------1630 • Brahe’s student---supposedly murdered Brahe so that he could take over his laws? • “Created” 3 laws of planetary motion: – Law of Orbit(1st) – Law of Equal areas(2nd) – Law of Harmonic Motion(3rd) Kepler website! • Johannes Kepler Astronomers KEPLER’S FIRST LAW COPY • “ALL PLANETS REVOLVE AROUND THE SUN IN ORBITS SHAPED LIKE AN ELLIPSE WITH THE SUN LOCATED AT ONE OF THE FOCUS POINTS(FOCI)” FOCUS POINTS Nothing over here! * SUN * PATH EARTH ELLIPSE Definitions: COPY • ORBIT: the path of a planet around the Sun • REVOLVE: planet’s movement around the Sun • ELLIPSE: a flattened circle with 2 focus points (foci) • Focus Points: FIXED points within an ellipse * ELLIPSE! CIRCLE: special ellipse with one focus point on top of the other! * * COPY ECCENTRICITY »How far from a perfect circle is an ellipse represented by a number between 0(circle) and 1(line). COPY * * * * * EQUATION(ESRT) e= distance between focus points(foci) Length of major axis(“diameter”) OR e= d L COPY * d L * “e” values are found with a ruler and are written out three numbers past the decimal point(thousandths place!) See Solar System Data in ESRT(Pg 15) Almost circular! NO UNITS!!!!! Farthest from a circle!

© Copyright 2024 Paperzz