Unit 9 Lesson 1: Earth and the Solar System

Front

What are wandering stars?

Back

Wandering stars are stars that do not appear to move like other stars; their relative location changes over several weeks.

Front

What does the term 'retro' mean in astronomy?

Back

In astronomy, 'retro' means backward.

Front

What are epicycles in the context of Ptolemy's model?

Back

Epicycles are small circles that planets move along while simultaneously orbiting a larger circle, used by Ptolemy to improve Aristotle's geocentric model.

Front

Who proposed the geocentric model of the solar system?

Back

Aristotle was the first astronomer to propose that the Earth was the center of our solar system.

Front

What type of orbits did Aristotle propose for planets, the sun, and the moon?

Back

Aristotle proposed that planets, the sun, and the moon move in circular orbits.

Front

What is the significance of the geocentric model?

Back

The geocentric model places Earth at the center of the universe, influencing astronomical thought for centuries.

Front

How did Ptolemy's model differ from Aristotle's?

Back

Ptolemy's model included epicycles to explain the retrograde motion of planets, while Aristotle's model did not.

Front

What is retrograde motion?

Back

Retrograde motion is the apparent backward movement of a planet as observed from Earth.

Front

What was the main flaw in the geocentric model?

Back

The main flaw in the geocentric model is that it could not accurately predict the positions of planets over time.

Front

What is the heliocentric model?

Back

The heliocentric model is the astronomical model that places the Sun at the center of the solar system, with planets orbiting around it.