The objects in our solar system called _______________ planets are giant gaseous planets similar in overall composition to Jupiter.   

 The __________   ____________ (two words) began when Copernicus used the writings of the Greek philosopher Aristarchus concerning a sun-centered theory because he appreciated its simplicity in its design.

In winter, Earth’s axis points toward the star Polaris. In spring: 

What are the two key properties of a telescope, and why is each important? Also distinguish between refracting and reflecting telescopes.

According to Kepler’s third law: 

What was the Copernican revolution, and how did it change the human view of the universe?

The Northern Hemisphere’s Winter season begins when the sun is at winter ___________________.

Briefly describe the Moon’s cycle of phases. Can you ever see a full moon at noon? Explain.

The atomic nuclei of the same element always have the same number of neutrons.

Within the frost line, planetesimals were composed entirely of rock, and outside the frost line, planetesimals were composed entirely of ice.