Astronomy Survey

What is astronomy?
science that studies the universedeals with properties of objects in spacelaws under which the universe operates
Geocentric view
earth-centered
heliocentric
sun-centered
Ancient Greeks
believed in the Geocentric view
Aristachus
1st Greek to believe in sun-centered universe and retrograde motion
Ptolemy 141 AD
Greek He figured out the planets’ motion using the wrong model (Geocentric model)
Copernicus, Nicolaus 1473 – 1543
He said Earth was a planetModel of the solar system was sun-centered or heliocentric. He said that Mercury, Venus, Earth, Mars, Jupiter, and Saturn orbit around the sun.
Brahe, Tycho 1546 – 1601
solar eclipsesstellar paralllax – shift in star’s position
Galileo Galilei 1564 – 1642Italian
teloscope in 16094 moons of Jupitersunspots
Newton 1643 – 1727
Law of Universal Gravitation3 laws of motion (inertia, forces, action/reactionsupported KeplerFather of Calculus
Kepler 1571- 1630
3 laws of planetary motion
Kepler’s 1st law
The orbits of the planets are ellipse, with the Sun at one focus of the ellipse
Kepler’s 2nd law
The line joining the planet to the Sun sweeps out equal areas in equal times as the planet travels around the ellipse
Kepler’s 3rd law
The ratio of the squares of the revolutionary periods for two planets is equal to the ratio of the cubes of their semi major axes.