Astronomy HW 2

A perfect circle has an eccentricity of ______.

• 0
• .99
• 1
• 2

The period of the earth's orbit around the sun is ____.

• 1 day
• 1 year
• 24 hours
• 364 hours

Which planet has an orbital eccentricity most like the orbital eccentricity of the Moon?

• Earth
• Saturn
• Mars
• Mercury

The gravitational attraction between the star and the planet will be greatest at position 

• A
• B
• C
• D

The length of an Earth day is determined by the time required for approximately one 

• Earth rotation
• Earth revolution
• Sun rotation
• Sun revolution

Which diagram shows a planet with the least eccentric orbit?

• 1
• 2
• 3
• 4

What is the maximum eccentricity an ellipse can be?

• 0
• .5
• 1
• 42

Calculate the eccentricity for the following orbit. 

• 1.6
• 0.8
• 0.6
• 1.2

What shape are the orbits of all planets in our solar system? 

• circular
• cylindrical 
• elliptical
• none of these

During which month is the earth moving the slowest? 

• July 
• March
• January
• September