Ancient Astronomy Flashcards
What did the Greeks believe in?
They believed that circles were the perfect shape
Eratosthenes
circumference of the Earth
Geocentric
The Earth is at the center
Celestial sphere
imaginary sphere around earth on the geocentric model that projects all stars and celestial objects
Heliocentric
Planets revolve around the sun
Aristotle
Figured out that the Earth was round due to shadows during the eclipse
Parellex
determining the length of an object to another
Copernicus
Believed in the heliocentric model
Why did the church reject Copernicus’ claims?
His claim went against the church doctrine; The heavens were perfect, so that means we should be the center of the solar system
Galileo
A great observer who studied phases on the moon, phases of Venus, moons of Jupiter, and sunspots
Tycho Brahe
A great observer whose solar system model introduced new astronomy
Johannes Kepler
Was hired by Brahe; plotted that Mars moved in an ellipse
Ellipse
Moving in an oval shape
What is Kepler’s first law of planetary motion?
All planets circle Sun in elliptical orbits; Sun at one focal point
What is Kepler’s second law of planetary motion?
An imaginary line connecting a planet to the Sun sweeps out equal areas in equal time; planets closer move faster
What is Kepler’s third law of planetary motion?
The square of a planet’s orbital period is proportional to the cube of the semi-major axis of its orbit
