Solar system

The Sun, planets and their moons, and a large collection of smaller objects such as asteroids, comets, and meteors are, together, called the:

• universe.

• galaxy

• solar system.

• nebulae.

A unit used to measure long distances, equivalent to the distance from the Sun to Earth, is known as the:

• light year.

• cosmic scale.

• astronomical unit.

• Parsec

Inner planets include all of the following EXCEPT:

• Neptune

• Mars

• Mercury

• Venus

. All of these objects in the night sky are seen because they reflect light EXCEPT:

• Earth’s moon

• stars

• Venus

• Mercury

The true shape of each planet’s actual orbit around the Sun is:

• perfectly circular.

• highly elliptical.

• irregular.

• slightly elliptical.

The force of gravity between two objects will be greatest if their masses are:

• small and they far apart.

• large and they are close together.

• large and they are far apart.

• small and they are close together.

Orbital motion of the planets is caused by the interaction between ____ and gravitational force:

• frictional forces.

• the strong nuclear force.

• the Sun’s energy.

• Inertia

Giant Impact Theory explains

• How dinosaurs went extinct

• How the Universe was formed

• How the Earth was formed

• How the moon was formed.

From Earth we always see the same side of the Moon because:

• the Moon does not rotate.

• the Moon and Earth rotate at the same rate.

• the Moon has the same period of rotation and revolution.

• Earth has the same period of rotation and revolution.

The gravitational force exerted on objects on the Moon is about 1/6 that of Earth. If an object weighs 240 newtons on the Moon, on Earth it would weigh:

• 40 N

• 240 N

• 1440 N

• 2352 N