The actual shape of Earth's orbit is

• a perfect circle

• an ellipse

• a sphere

• a triangle

The diagram below represents a simple geocentric model. Which object is represented by the Letter X?

• Sun

• Moon

• Earth

• Polaris

The diagram represents our solar system. The system is best classified as

• heliocentric, with circular orbits

• heliocentric, with elliptical orbits

• geocentric, with circular orbits

• geocentric with elliptical orbits

In the geocentric model, which motion would occur?

• Earth would revolve around the sun.

• Earth would rotate on its axis.

• The moon would revolve around the sun.

• The sun would revolve around Earth.

Which statement best describes the geocentric model of the solar system?

• All planets revolve around the sun.

• The sun is located at the center of the model.

• The Earth is located at the center of the model.

• All planets except Earth revolve around the sun.

A red shift of light from very distant galaxies suggest that the universe is

• fixed and stationary

• moving randomly

• expanding

• contracting

Which evidence best supports the Big Bang Theory?

• existence of cosmic background radiation

• rate of rotation of the sun

• uniform radioactive decay of Uranium-238

• separation of Earth's interior into different layers

The diagram represents planets A and B, of equal mass, revolving around a star. Compared to planet A, planet B has a

• weaker gravitational attraction to the star and a shorter period of revolution

• weaker gravitational attraction to the star and a longer period of revolution

• stronger gravitational attraction to the star and a shorter period of revolution

• stronger gravitational attraction to the star and a longer period or revolution

The terrestrial planets differ from the Jovian planets because the terrestrial planets are

• less dense and larger

• less dense and smaller

• more dense and larger

• more dense and smaller

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

• Earth revolution

• Earth rotation