Ancient astronomy Geocentric Heliocentric Mass and Gravity GalileoKepler Newton $ 200 $ 200$200 $ 200 $ 200 $400 $ 400$400 $ 400$400 $600 $ 600$600 $ 600 $ 600 $ 600 $800 $ 800$800 $ 800 $ 800 $ 800 $ 1000$1000 $ 1000 $ 1000 $ 1000 $ 1000

$200 Tycho Brahe and Kepler The reason scientist no longer accept the Ptolemaic model is due to the work of

$400 Orbits of planets are circular Ptlomey and Copernicus Incorrectly agreed that

$600 Venus and Mercury A fatal flaw of Ptolemy’s model is it’s inability to predict the phases of

$800 Aristarchus The heliocentric model was actually first proposed by:

$1000 How did Galileo’s observations of Venus disprove Ptolemy? Ptolemy used epicycles for Venus to explain the earth centered universe, which could not explain why we see a full Venus phase. Galileo observe that Venus goes through a full Venus cycle and therefor the sun must be in the center

$200 Copernicus Who did Kepler correct by describing orbits as elliptical rather than circular?

$400 The moon orbiting the Earth What celestial relationship is the same in both the heliocentric and geocentric models?

$600 Brahe Whose detailed observations led to Kepler’s Laws

$800 Show me your answers Name three differences between the geocentric and heliocentric models

$1000 The Earth moves faster than these outer world, so we overtake them and as we sweep past them they appear to go westward for a few weeks Explain how Copernicus accounts for the retrograde loops of the superior planets

$200 Overcome the gravitational pull of an object Escape velocity is the speed required to

$400 One fourth as great If the distance between two asteroids is doubled, the gravitational force they exert on each other will be

$600 The mean distance between the Earth and Sun? What is an Astronomical Unit?

$800 If the Moon was three times further from Earth, the force by Earth on the Moon would Decrease by a factor of 9

$1000 The higher the eccentricity the more elongated the oval, a circle has an eccentricity of zero Explain how eccentricity describes the shape of an ellipse

$200 Jupiter Galileo’s discovery of four moons orbiting ________ helped support the ideas of Copernicus

$400 He laid out the order and relative motion on the known solar system What contribution did Copernicus make that helped Galileo in his observations?

$600 Sunspots which rotated across the sun’s face What did Galileo discover when looking at the sun?

$800 Sunspots, Venus phase cycle Four moons around Jupiter Craters and mare on the Moon What are three things Galileo discovered through his telescope?

$1000 Galileo found Venus went through an entire phase cycle which could only happen in the Copernican model How did Galileo’s observations of Venus disprove the Ptolemaic model?

$200 Kepler Whose laws described Planetary motion

$400 What point do Copernicus and Kepler disagree? The orbits of the planets are ellipses with one focus at the sun.

$600 Proportional to the cube of its semi-major axis According to Kepler’s third law, the square of the planet’s period in years is

$800 Planets further from the sun orbit at a slower speed than those closer What does Kepler’s third law imply about planetary motion?

$1000 Relate Keplar’s Second Law to the speed of planets In equal amounts of time, the lines that connect each planet to the sun must sweep out in equal areas. The longer the arc, the faster the planet must move. The further the line from the sun the slower a planet moves. Planets in perihelion will speed up and in aphelion they will slow down.

$200 Newton The Law of Universal Gravitation was developed by

$400 smaller According to Newton’s second law, when the same force acts on two bodies, the body with the larger mass will have the _______acceleration

$600 sun According to Newton, the gravity of the _______ is needed to explain planetary orbits.

$800 That objects have mass that disrupt the space around them –curving space and other objects towards that object. What did Einstein have to say about Gravity?

$1000 The third law says they each have the same gravitational pull, butJupiter is more massive than a Voyager, which the second law allows Jupiter to slow a bit and the Voyager to accelerate allow them to escape the gravitational pull of the sun. Using Newton’s second and third law explain why the Voyager probes able to pull away from Jupiter and yet Jupiter still orbits around the sun