Flashcard Module 22 Lesson 1

Front

Who proposed the heliocentric model of the solar system, challenging the previously accepted geocentric view?

Back

Nicolaus Copernicus

Front

What is the term for the apparent backward motion of planets in the night sky?

Back

Retrograde motion

Front

The formation of our solar system began with what astronomical event?

Back

A collapsing interstellar cloud

Front

What are the small, rocky bodies that formed during the early solar system called?

Back

Planetesimals

Front

Which astronomer made detailed observations of planetary motions but still believed Earth was the center of the universe?

Back

Tycho Brahe

Front

What is the average distance between Earth and the Sun called?

Back

Astronomical unit

Front

Which model of the universe places Earth at the center?

Back

Geocentric model

Front

Kepler's First Law states that planetary orbits are:

Back

Elliptical

Front

The measure of how much an elliptical orbit deviates from circular is called:

Back

Eccentricity

Front

In an elliptical orbit, what is the longest axis called?

Back

Semimajor axis