Which does NOT have an effect on how strongly the Sun pulls on an object in space?

• the mass of the object
• how far the object is away from the Sun
• the fact that the Sun is made of a mixture of gases
• the mass of the Sun

A galaxy that has a shape similar to a football is a(n) _____ galaxy.

• spiral
• elliptical
• irregular

As the solar system developed, larger bodies were pushed away from its center by gravity.

• true
• false

Two of the inner planets are _____.

• Venus and Saturn
• Mars and Venus
• Earth and Pluto
• Mercury and Jupiter

The order of the inner planets outward from the Sun is ____.

• Mercury, Earth, Venus, and Mars
• Mercury, Venus, Earth, and Mars
• Mars, Venus, Earth, and Mercury
• Earth, Venus, Mars, and Mercury

Which does NOT describe our Sun?

• it is part of the Milky Way galaxy
• it is the center of the universe
• it is one of billions of stars

Which of the following data can help someone to infer the size of a planet?

• how many moons it can capture due to its pull of gravity
• how far it is from the Sun in km
• its surface temperature in degrees
• its surface geography

Gravity causes cast off gases to clump together to begin forming new stars and planets.

• true
• false

What causes planets and other space objects to revolve around the Sun rather than traveling in a straight line as indicated by the solid arrows in the picture below?

• Friction
• Gravity
• Buoyancy

Which of the following is defined as a huge collection of gas, dust, and stars held together by gravity?

• nebula
• solar system
• galaxy
• universe