27.2 Review

A closed curve defined by two points called foci.

• Ellipse
• Oval
• Circle
• Orbit

The degree of elongation of an elliptical orbit.

• Orbital period
• Eccentricity
• Equal areas
• Circumference

A pattern that makes it appear as though planets are moving backwards in the sky.

• Rotation
• Revolution
• Retrograde motion
• Prograde motion

Sun centered

• Solcentric
• Geocentric
• Geologic
• Heliocentric

Earth centered

• Geocentric
• Solcentric
• Geologic
• Heliocentric

The tendency of a stationary body to remain at rest unless acted upon by an outside force.

• Momentum
• Inertia
• Law of Equal Areas
• Gravity

The force that exists between any two bodies in the universe.

• Inertia
• Magnetic
• Gravity
• Centrifugal

The time required for a body to complete a single orbit.

• Sol
• Year
• Orbital period
• Revolution time

What law describes the relationship between the planet’s average distance from the sun and the planet’s orbital period?

• Law of Periods
• Law of Ellipses
• Law of Equal Areas
• Law of Inertia

What law describes how a planet orbits the sun?

• Law of Periods
• Law of Ellipses
• Law of Equal Areas
• Law of Inertia