Solar System Moons - An Introduction to AstronomyAn Introduction to Astronomy
Solar System Moons
1.      Which of the following Solar System moons are associated with the planet Mercury?
A.     Mercury has no moons.
B.     Phobos and Deimos
C.     Io, Europa, Ganymede, Callisto
D.     Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Iapetus
E.     Miranda, Ariel, Umbriel, Titania, Oberon
F.     Proteus, Triton, Nereid
2.      Which of the following Solar System moons are associated with the planet Venus?
A.     Venus has no moons.
B.     Phobos and Deimos
C.     Io, Europa, Ganymede, Callisto
D.     Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Iapetus
E.     Miranda, Ariel, Umbriel, Titania, Oberon
F.     Proteus, Triton, Nereid
3.      Which of the following Solar System moons are associated with the planet Mars?
A.     Mars has no moons.
B.     Phobos and Deimos
C.     Io, Europa, Ganymede, Callisto
D.     Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Iapetus
E.     Miranda, Ariel, Umbriel, Titania, Oberon
F.     Proteus, Triton, Nereid
Phobos and Deimos.  The origin of these relatively small moons remains uncertain but asteroid capture is a long-favored theory.  Phobos is projected to either impact the Martian surface, or more probably, break up into a planetary ring which will continue to spiral slowly into Mars in an estimated 7.6 to 11 million years.
4.      Which of the following Solar System moons are associated with the planet Jupiter?
A.     Jupiter has no moons.
B.     Phobos and Deimos
C.     Io, Europa, Ganymede, Callisto
D.    Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Iapetus
E.     Miranda, Ariel, Umbriel, Titania, Oberon
F.     Proteus, Triton, Nereid
Jupiter has 66 moons but Io, Europa, Ganymede and Callisto are the four largest.  All four have radii larger than any of the dwarf planets. These are also known as Galilean Moons.
5.      Which of the following Solar System moons are associated with the planet Saturn?
A.     Saturn has no moons.
B.     Phobos and Deimos
C.     Io, Europa, Ganymede, Callisto
D.     Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Iapetus
E.     Miranda, Ariel, Umbriel, Titania, Oberon
F.     Proteus, Triton, Nereid
Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Iapetus. Saturn has at least 62 moons, 53 of which have formal names.  Titan, the largest with a mean diameter of 5,152 km (3,200 miles), makes up 90% of the mass in orbit around Saturn, including the rings.  Rhea, the 2nd largest, has a mean radius about 30% that of Titan. Many of Saturn’s other moons are less than 50 km (31 miles) in diameter.
6.      Which of the following Solar System moons are associated with the planet Uranus?
A.     Uranus has no moons.
B.     Phobos and Deimos
C.     Io, Europa, Ganymede, Callisto
D.     Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Iapetus
E.     Miranda, Ariel, Umbriel, Titania, Oberon
F.     Proteus, Triton, Nereid
Miranda, Ariel, Umbriel, Titania, Oberon. Uranus has 27 known moons but Miranda, Ariel, Umbriel, Titania, and Oberon compose the five main natural satellites. The Uranian satellite system is the least massive among the gas giants. The largest moon, Titania, has a diameter of only 1578 km ( 980 miles).
7.      Which of the following Solar System moons are associated with the planet Neptune?
A.     Neptune has no moons.
B.     Phobos and Deimos
C.     Io, Europa, Ganymede, Callisto
D.     Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Iapetus
E.     Miranda, Ariel, Umbriel, Titania, Oberon
F.     Proteus, Triton, Nereid
Proteus, Triton, Nereid. Neptune has 13 known moons. Triton, with a diameter of 2700 km (1,680 miles), is by far the largest, comprising more than 99.5 percent of the mass in orbit around Neptune.
Solar System Moons – Descriptions
8.      What is the name of this solar system object?
Full Moon as seen from the Earth’s Northern Hemisphere.
A.     The Moon
B.     Mercury
The Moon.   The Moon is the only natural satellite of the Earth, and is the fifth largest of the Solar System moons.  It is characterized by its large, dark volcanic maria which form part of the “Man in the Moon.”  The Moon is, under the Outer Space Treaty, free to all governments and privately funded organizations to explore for peaceful purposes.  The Moon orbits at an elliptical semi-major axis distance of 384,399 km (238,854 miles) around the Earth and its mean  diameter is 3,475 km (2,160 miles), about ¼ the size of the  Earth.
9.      What is the name of this solar system object?
A.     Phobos
B.     Deimos
Mars larger and closer Moon, Phobos.
Phobos.  Mars moon, Phobos, is the larger and closer of the two small natural satellites orbiting Mars.  Phobos is projected to either impact the Martian surface, or more probably break up into a planetary ring which will continue to spiral slowly into Mars in an estimated 7.6 to 11 million years.  Phobos orbits at an elliptical semi-major axis distance of 9,377 km (5,827 miles) around Mars and its mean diameter is 22.2 km (13.8 miles). 
10.      What is the name of this solar system object?
Mars smaller and outer Moon, Deimos.
A.     Phobos
B.     Deimos
Deimos.  Mars moon, Deimos, is the smaller and outer of the two small natural satellites orbiting Mars.  Both Phobos and Deimos were discovered by Asaph Hall, Sr. at the United States Naval Observatory in August 1877 while deliberately searching for Martian moons – Deimos on August 12th and Phobos on August 18th.  Deimos  orbits at an elliptical semi-major axis distance of 23,460 km (14,580 miles) around Mars and its mean diameter is 12.4 km (7.8 miles).
11.      What is the name of this solar system object?
Jupiter’s innermost Galilean Moon, IO.
A.     Io
C.     Ganymede
D.     Callisto
Io.  Jupiter’s moon, Io, is the innermost of the four Galilean moons orbiting the planet Jupiter.  With over 400 active volcanos, Io  is the most geologically active object in the solar system.  This  activity is a result of tidal heating in its interior as it pulled between Jupiter and the other Galilean satellites, Europa, Ganymede, and Callisto. Most of Io’s surface is covered with sulfur and sulfur dioxide frost.  Io orbits at a radius of 422,000 km (262,000 miles) from the center of Jupiter and 350,000 km (217,000 miles) above its cloud tops.  Io’s mean diameter is 3,640 km (2,260 miles).
12.      What is the name of this solar system object?
Jupiter Moon, Europa.
C.     Ganymede
D.     Callisto
Europa.  Jupiter moon, Europa, is the smallest of the four Galilean moons of Jupiter, being slightly smaller than Earth’s Moon.  Europa has a tenuous atmosphere composed mostly of molecular oxygen (O2) formed through the process of radiolysis rather than biologically as is the case for the Earth’s atmospheric oxygen.  Europa is one of the top Solar System locations for the possibility of hosting extraterrestrial life, which could exist in its underice ocean.   Europa orbits Jupiter at an orbital radius of 670,900 km (417,000 miles) from the center of Jupiter and its mean diameter is 3,100 km (1,950 miles).
13.      What is the name of this solar system object?
Jupiter Moon, Ganymede.
Enceladus.  Saturn moon, Enceladus, is one of only
three outer Solar System moons (along with Jupiter’s moon
Io and Neptune’s moon Triton) where active eruptions have
been observed.  Analysis of the outgassing suggests that they originate from a body of subsurface liquid water.  This observation, along with the unique chemistry found in the plume, has fueled speculation that Enceladus may be important in the study of astrobiology.  NASA scientists have reported (In May 2011) that Enceladus “is emerging as the most habitable spot beyond Earth in the Solar System for life as we know it.”  Enceladus orbits at an elliptical semi-major axis distance of 238,000 km (148,000 miles) around Saturn and its mean diameter is 500 km ( 310 miles).
17.      What is the name of this solar system object?
Saturn Moon, Tethys.
D.     Titania
E.     Oberon
Oberon.  Uranus moon, Oberon, is the outermost major moon of the planet, Uranus.  Oberon is the second largest and second most massive of the Uranian moons.  Like Titania,  the surface of Oberon is relatively dark and slightly red in color.  Oberon orbits at an elliptical semi-major axis distance of  583,500 km (362,600 miles) around Uranus and its  mean diameter is 1,520 km ( 945 miles).
27.      What is the name of this solar system object?
Neptune Moon, Proteus.
B.     Triton
C.     Nereid
Proteus.  Neptune moon, Proteus, is the second largest moon of Neptune behind the mysterious Triton.  Proteus was  discovered only in 1989 by the Voyager 2 spacecraft.  This is  unusual since Neptune’s smaller moon, Nereid, was discovered  33 years earlier from Earth.  Proteus orbits at an elliptical semi-major axis distance of 117,650 km (73,120 miles) around Neptune and its mean diameter is 210 km (131 miles).
28.      What is the name of this solar system object?
Neptune Moon, Triton.
B.     Triton
C.     Nereid
Triton.  Neptune’s largest moon, Triton, is the only large  moon in the Solar System with a retrograde orbit, which is  an orbit in the opposite direction to its planet’s rotation.  Because of its retrograde orbit and composition similar to Pluto’s, Triton is thought to have been captured from the Kuiper belt.  Triton orbits at an elliptical semi-major axis distance of 355.000 km (220,000 miles) around Neptune and its mean diameter is 1350 km (840 miles).
29.      What is the name of this solar system object?
Neptune Moon, Nereid.
B.     Triton
C.     Nereid
Nereid.  Neptune moon, Nereid, is the third-largest moon of Neptune and has a highly eccentric orbit.  It was discovered in 1949 on photographic plates taken with the 82-inch telescope at the McDonald Observatory at the University of Texas at Austin.  Nereid orbits at an elliptical semi-major axis distance of about 5,510,000 km (3,425,000 mi) around Neptune, but its high eccentricity of 0.7507 takes it as close as 1,372,000 km (853,000 mi) and as far as 9,655,000 km (5,999,000 mi) from the planet.  Its mean diameter is roughly 170 km (105 miles).
30.     Which of the following are the names of the Solar System moons of the dwarf planet, Pluto?
A.     Charon, Nix, Hydra, S/2011, S/2012
B.     Dysnomia
C.     Hi’iaka, Namaka
A.     Charon, Nix, Hydra, S/2011, S/2012.   Charon and Pluto revolve about each other every 6 days. The two objects are gravitationally locked, so each keeps the same face towards the other.  The average distance between Charon and Pluto is 19,570 km (12,160 miles).  Charon’s mean diameter is 1.207 km (750 miles), just over half the diameter of Pluto.  
Nix and Hydra orbit Pluto at approximately two and three times the distance of Charon: Nix at 48,700 km (30,267 miles) and Hydra at 64,800 km (40,273 miles) from the barycenter of the system.  They have nearly circular prograde orbits in the same orbital plane as Charon.  Observations of Nix and Hydra to determine individual characteristics are ongoing.
31.     Which of the following are the names of the Solar System moons of the dwarf planet, Eris?
A.     Charon, Nix, Hydra, S/2011, S/2012
B.     Dysnomia
C.     Hi’iaka, Namaka
B.     Dysnomia.  Dysnomia is the only known moon of the dwarf planet, Eris.
32.     Which of the following are the names of the Solar System moons of the dwarf planet, Haumea?
A.     Charon, Nix, Hydra, S/2011, S/2012
B.     Dysnomia
C.     Hi’iaka, Namaka
C.     Hi’iaka, Namaka.  Hi’iaka, the larger, outermost moon, has large amounts of pure water ice on its surface and orbits Haumea in a nearly circular path every 49 days.  Namaka, about one tenth the mass of Hi’iaka, orbits Haumea in 18 days in a highly elliptical orbit.
REFERENCES:  Most of the content in this section regarding the Solar System moons consists of  information from this NASA reference and from this Wikipedia.org reference , and their associated pages.