Moons

Only two planets in our solar system have no moons. They are:

• Venus and Neptune

• Mercury and Jupiter

• Mars and Pluto

• Mercury and Venus

The planet which has the largest moon, relative to its size, is:

• Jupiter

• Earth

• Saturn

• Pluto

Luna, the first unmanned spacecraft to reach Earth's moon, was sent by this country in 1959:

• United States

• Soviet Union

• China

• India

Mars has a total of this many moons:

• 1

• 2

• 3

• 4

This moon orbits its planet more closely than any other moon in our solar system:

• Deimos

• Phobos

• Ariel

• Enceladus

Phobos, whose name comes from the Greek word for "fear," orbits this planet:

• Venus

• Mars

• Saturn

• Neptune

This moon's two largest craters are named Swift and Voltaire:

• Deimos

• Phobos

• Ganymede

• Luna

Deimos was discovered in 1877 by:

• Christiann Huygens

• Asaph Hall III

• Galileo Galilei

• William Herschel

The four Galilean moons of Jupiter are Io, Callisto, Ganymede, and:

• Titan

• Titania

• Uriel

• Europa

This moon of Jupiter is the most geologically active body in our solar system:

• Callisto

• Ganymede

• Io

• Europa