The Solar System

Why was it difficult for people to accept a heliocentric concept of the solar system?

• Scientists had no way to explain retrograde motion.

• Scientists did not check or confirm other scientists' ideas.

• Information was published in Italian and people could not understand it.

• Aristotle was famous and his ideas were supported by religious teachings.

Which idea did Ptolemy’s model use to explain why the planets appeared to move backward as they moved in their orbits? 

• The planets spun in epicycles.

• The planets rotated on their axes.

• The planets revolved around the Sun.

• The planets were made of different materials.

Which idea was supported by Aristarchus, Copernicus, and Galileo?

• The planets have epicycles.

• The planets revolve around the Sun.

• The stars rotate around the Sun.

• The center of the solar system is Earth.

Look at the diagram of the solar system.

What observation did the geocentric model of the solar system help to explain?

• Orbit speed

• the phases of Venus

• retrograde motion

• the rising of the Sun

Which describes one way that Aristarchus's explanation of the movement of objects in the sky was different from other scientists' earlier explanations?

• He discovered Venus's phases.

• He argued that Earth rotates on its axis

• He explained the concept of retrograde motion.

• He described the epicycles of the planets in the sky.

How did Kepler's discoveries contribute to astronomy?

• They supported the heliocentric model.

• They established the laws of planetary motion.

• They explained how the Sun rises and sets.

• They made astronomy accessible to people who spoke Italian.

Which event took place during the Copernican revolution, when most people started to believe in a heliocentric model of the solar system?

• Aristotle developed his model of the solar system.

• Copernicus rediscovered Aristarchus's heliocentric model.

• Kepler's laws of planetary motion.

• Newton's theories of gravity were dismissed and considered invalid.

In addition to proposing that planetary orbits are elliptical, what other modification did Kepler make to Copernicus's model?

• Planets closer to the Sun move faster.

• Planets spin in an epicycle while orbiting Earth.

• Venus has phases due to its orbiting of the Sun.

• Earth's rotation causes the rising and setting of the Sun.

Which correctly lists three scientists who supported teh heliocentric model of the solar system?

• Aristotle, Ptolemy, Copernicus

• Copernicus, Ptolemy, Kepler

• Galileo, Kepler, Aristotle

• Kepler, Galileo, Copernicus

Why was Copernicus's heliocentric model not believed until Galileo and Kepler provided more evidence?

• The model had the moon orbiting the Earth.

• The model was againest religious teachings.

• The model could not explain retrograde motion.

• The model did not include all eight planets in the solar system.