Astronomy was once known as the study of the night sky.  Today astronomy is officially known as the study of what?

• the solar system
• the universe
• the galaxy
• everything outside Earth's atmosphere

Which astronomer supported the idea of an earth-centered universe?

• Ptolemy
• Brahe
• Kepler
• Copernicus

Which astronomer was the first to talk about a sun-centered universe?

• Ptolemy
• Brahe
• Kepler
• Copernicus

Which astronomer said the sun and the moon revolved around the earth, but all the other planets revolved around the sun?

• Ptolemy
• Brahe
• Kepler
• Galileo

Which astronomer used a telescope to prove that the planets revolved around the sun?

• Ptolemy
• Brahe
• Kepler
• Galileo

Which astronomer said that all planets revolve around the sun, but not in circular orbits?

• Ptolemy
• Brahe
• Kepler
• Galileo

Newton's Law of Gravity explained why the planets orbit the sun. 

• The sun is a star.
• The sun was there first.
• The sun is the most massive.
• The sun has both a magnetic and gravitational field.

What kind of telescope did Galileo build?

• reflecting
• refracting
• microscope
• a tiny one

What kind of telescope did Isaac Newton build?

• reflecting
• refracting
• microscope
• a big one

The force of gravity between two objects depends on the mass of the objects and what else?

• the distance between them
• the speed of objects
• the acceleration of the objects
• the direction of the objects motion