Galaxy & Gravity Review

Where is the sun located in the galaxy?

• within the center body

• within an outer arm

• at the center

• at the edge

In what galaxy are Earth and the solar system located?

• The Whirlpool galaxy

• The Local Group Galaxy

• The Milky Way Galaxy

• The Andromeda Galaxy

What information provided evidence for the location of the sun in the galaxy?

• observation of elliptical orbits of planets around the sun

• measurement of relative brightness of stars within the galaxy

• observation of globular clusters

• determination of the composition of stars within the galaxy

Why are Earth, other solar system planets, and most planetary objects spherical?

• pressure of atmosphere acting evenly in all directions on the object’s surface.

• force of gravity acting evenly in all directions around the center of mass

• heat received from the sun melting the object’s surface at the time of formation

• erosion made by asteroids hitting the object’s surface after the object’s formation

What can you conclude about the dark areas of the night sky?

• Objects in the dark areas of the sky are too far away from Earth to be seen.

• There is nothing located in the dark areas of the sky.

• Objects in the dark areas are moving too fast to be visible.

• Black holes make up the dark areas of the sky.

Two objects have a certain gravitational force between them. What would happen if the mass of one of the objects suddenly increased?

• The distance between the objects would increase.

• The mass of the other object would increase.

• The gravitational force between the two objects would increase.

• The gravitational force of the objects would remain constant.

A satellite is orbiting Earth. What would happen to the satellite if Earth’s gravity suddenly disappeared?

• The satellite would continue to orbit Earth.

• The satellite would fall to Earth.

• The satellite would stop moving.

• The satellite would move into space in a straight line.

Which object exerts the greatest gravitational pull in our Solar System?

• Our Moon

• Earth

• Jupiter

• The Sun

What would happen to the moon if the gravitational pull of Earth decreased?

• The moon would explode

• The moon would continue to orbit the Earth

• The moon would no longer orbit the Earth

• The moon would crash into the Earth

The dotted lines in the picture show orbital paths of objects. Which statement is true about all of the orbits shown?

• The force of gravity is what holds each object in its orbit

• The size of both an object and the object it orbits are equal.

• All objects move in circular orbits.

• The size of an object determines the size of its orbit.