'Amateur Astronomy'. Tables and Size Comparison Charts for the Moons in The Solar System

Tables and Size Comparison Charts for the Moons in The Solar System

note! all values in the following tables are given in the metric system, which is the original format of data as taken from NASA's National Space Science Data Center (NSSDC)

Terrestrial Planets' Moons (Size Comparison Charts and Tables)
Gas Giants' Moons (Size Comparison Charts and Tables)

for values specifications, see below

Terrestrial Planets' Moons (Size Comparison Charts and Tables)

click to a terrestrial planets comparison chart of planets and moons (a recall of the diagram is put to scale with the gas giants' moons charts below)

Data About Terrestrial Planets' Moons
		Semimajor axis (in km)	Radius (in km) (1)	Orbital Period (in days)	Rotation (in days) (2)	Orbit Inclination (in ° relative to planet's equator)	Eccentricity	Mass (in 10¹⁵ kg, 10²¹ for Charon)	Mean Density (in kg/m³)	Albedo
Mars (total: 2)	Phobos	9,378	13.4 x 11.2 x 9.2	0.319	0.319 S	1.08	0.0151	10.6	1,900	0.07
Mars (total: 2)	Deimos	23,459	7.5 x 6.1 x 5.2	1.262	1.262 S	1.79	0.0005	2.4	1,750	0.08
Pluto (total: 5)	Charon	19,600	593	6.39	6.39 S	0.0	0.0	1.9	2,000	0.38
Pluto (total: 5)	Diminutive Satellites: Nix and Hydra have been discoverd by 2005 by New Horizons team members in Hubble Space Telescope images. They orbit by 40 000 and 30 000 miles from the planet with a size about 20-70 miles (32-113km) and a period about 38 day. A fourth and fifth satellite were discovered in 2011 and 2012 respectively. Styx, between the orbits of Charon and Nix, just 4 to 13 miles across is orbiting its mother-planet each 20 days as Kerberos, orbiting between Nix and Hydra with a 32-day period is 6 to 20 miles in diameter. Both are 20 to 30 times fainter than Nix and Hydra. Pluto's diminutive moons wobble because they orbit the double system of Pluto-Charon which further has a gravitational field that shifts constantly. The effect is strengthened moons' small size. Three of Pluto’s moons are locked together in resonance as Kerberos is as dark as a charcoal briquette; other frozen moons are as bright as sand. Chaos may be a common trait of binary systems. Pluto's moons are believed to have been formed by a collision between the dwarf planet and a similar-sized body early in the history of our solar system. The smashup flung material that consolidated into the family of moons observed today. As nearly every other moon in the solar system is in a synchronous rotation, keeping one face toward the planet, this is not the case for Pluto’s diminutive moons. Pluto’s small lunar satellites are spinning much faster, with Hydra -the most distant one- rotating an unprecedented 89 times during a single lap. Scientists believe these spin rates may be variable because Charon exerts a strong torque that prevents each small moon from settling down into synchronous rotation. Those small moons also are wobbling to a high degree

data NASA's National Space Science Data Center (NSSDC)

(1) back S stands for synchroneous. The rotational period equals the orbital period
(2) back when the moon is an irregular body dimensions are the major axis radius, the median axis radius, and the minor axis radius, in this order

Gas Giants' Moons (Size Comparison Charts and Tables)

click to a gas giants comparison chart of planets and moons (with a recall, to scale, of the terrestrial planet's moons diagram)

in the following table all moons sorted by distance from the planet

Data About Gas Giants' Moons
		Semimajor axis (in 10³km)	Radius (in km) (1)	Orbital Period (in days) (2)	Rotation (in days) (3)	Orbit Inclination (in deg; relative to the planet's equator)	Eccentricity	Mass (in 10²⁰ kg)	Mean Density (in kg/m³)	Albedo
Jupiter (total: 79)
Inner Moons	Metis	128.1	20	0.294780	0.294780 S	0.02	0.001	0.001		0.06
	Adrastea	128.9	13x10x18	0.29826	0.29826 S	0.03	0.002	0.0002		0.10
	Amalthea	181.4	131x73x67	0.498179	0.498179 S	0.40	0.003	0.075	3,100	0.09
	Thebe	221.9	55x45	0.6745		0.8	0.018	0.008		0.05
Galilean Satellites	Io	421.6	1,821.6	1.769138	1.769138 S	0.04	0.004	893.2	3,530	0.62
	Europa	670.9	1,560.8	3.551181	3.551181 S	0.47	0.0101	480.0	3,010	0.68
	Ganymede	1,070.4	2,631.2	7.154553	7.154553 S	0.21	0.0015	1,481.9	1,940	0.44
	Callisto	1,882.7	2,410.3	16.689018	16.689018 S	0.51	0.007	1,075.9	1,830	0.19
Irregular Satellites	Themisto	7,507	4	130.02		45.67	0.242			0.04
	Leda	11,170	5	240.92		27.47	0.164	0.00006		0.07
	Himalia	11,460	85	250.5662	0.4	27.63	0.162	0.095		0.03
	Lysithea	11,720	12	259.22		27.35	0.112	0.0008		0.06
	Elara	11,740	40	259.6528	0.5	24.77	0.217	0.008		0.03
	S/2000 J11	12,560	2.0	287.0		28.3	0.248			0.04
	Carpo	17,100	3.0	456.5		55.1	0.295
	S/2003 J3	18,340	2.0	504.0R		143.7	0.241
	S/2003 J12	19,000	1.0	533.3R		145.8	0.376
	Euporie	19,390	1.0	553.1R		147.0	0.156
	S/2003 J18	20,700	2.0	606.3R		146.5	0.119
	Helike	20,980	4.0	617.3R		156.1	0.157
	S/2003 J16	21,000	2.0	595.4R		148.6	0.270
	Euanthe	21,030	1.5	620.0R		145.9	0.176
	Harpalyke	21,110	2.2	623.3R		148.7	0.227			0.04
	Praxidike	21,150	3.4	625.3R		148.7	0.220			0.04
	Orthosie	21,170	1.0	623.0R		141.9	0.272
	Hermippe	21,250	2.0	631.9R		150.3	0.251
	Iocaste	21,270	2.6	631.5R		159.7	0.218			0.04
	Ananke	21,280	10	629.8R		148.9	0.244	0.0004		0.06
	Thyone	21,310	2.0	632.4R		149.0	0.295
	S/2003 J15	22,000	2.0	668.4R		140.8	0.110
	S/2003 J17	22,000	2.0	690.3R		163.7	0.190
	Kallichore	22,400	2.0	683.0R		163.9	0.223
	S/2003 J9	22,440	1.0	683.0R		164.5	0.269
	S/2003 J19	22,800	2.0	701.3R		162.9	0.334
	Arche	22,930	1.5	723.9R		165.0	0.259
	Pasithee	23,030	1.0	716.3R		165.4	0.288
	Kale	23,120	1.0	720.9R		165.3	0.475
	Chaldene	23,180	1.9	723.8R		165.4	0.238			0.04
	Eurydome	23,220	1.5	720.8R		150.1	0.345
	Isonoe	23,220	1.9	725.5R		165.0	0.261			0.04
	S/2003 J4	23,260	2.0	723.2R		144.9	0.204
	Erinome	23,280	1.6	728.3R		164.9	0.270			0.04
	Taygete	23,360	2.5	732.2R		165.2	0.251			0.04
	Carme	23,400	15	734.2R		164.9	0.253	0.001		0.06
	Aitne	23,550	1.5	741.0R		165.7	0.291
	Kalyke	23,580	2.6	743.0R		165.2	0.243			0.04
	Pasiphae	23,620	18	743.6R		151.4	0.409	0.003		0.10
	Aoede	23,810	4.0	748.8R		159.4	0.405
	Sponde	23,810	1.0	749.1R		155.0	0.454
	Megaclite	23,810	2.7	752.8R		152.7	0.425			0.04
	Sinope	23,940	14	758.9R		158.1	0.250	0.0008		0.05
	Cyllene	24,000	2.0	737.8R		141.0	0.412
	S/2003 J5	24,080	4.0	759.7R		165.0	0.210
	Callirrhoe	24,100	4	758.8R		147.1	0.283			0.04
	Autonoe	24,120	2.0	765.1R		151.9	0.415
	S/2003 J10	24,250	2.0	767.0R		164.1	0.214
	Hegemone	24,510	3.0	781.6R		152.6	0.264
	Eukelade	24,560	4.0	781.6R		163.4	0.345
	S/2003 J14	25,000	2.0	807.8R		140.9	0.222
	S/2003 J2	28,570	2.0	982.5R		151.8	0.380
Additional Finds	A total of 19 additional finds were added to that list, of which 12 by July 2018
Saturn (total: 82)
Inner Satellites (some intermingled with some of the following)	Pan	133.583	10	2.2165	0.5750	0.0	0.000	0.00003	630	0.5
	Atlas	137.670	18.5 x 17.2 x 13.5	2.2820	0.6019	0.3	0.000	0.0001	630	0.8
	Prometheus	139.353	74 x 50 x 34	2.2843	0.6130	0.0	0.0024	0.0033	630	0.5
	Pandora	141.700	55 x 44 x 31	2.3512	0.6285	0.0	0.0042	0.0020	630	0.7
	Epimetheus (4)	151.422	69 x 55 x 55	0.6942	0.6942 S	0.34	0.009	0.0054	600	0.8
	Janus (4)	151.472	97 x 95 x 77	0.6945	0.6945 S	0.14	0.007	0.0192	650	0.9
	S/2004 S1	194.000	1.5
	S/2004 S2	211.000	2
	Calypso	294.66	15 x 8 x 8	4.8892	1.8878	ab. 0	ab. 0	0.00004	1,000	1.0
	Telesto	294.66	15 x 12.5 x 7.5	4.8892	1.8878	ab. 0	ab. 0	0.00007	1,000	1.0
	Helene	377.40	18 x 16 x 15	6.262	2.7369	0.0	0.005	0.0003	1,500	0.7
Regular Satellites	Mimas (5)	185.52	209 x 196 x 191	0.9424218	0.9424218 S	1.53	0.0202	0.375	1,140	0.5
	Enceladus	238.02	256 x 247 x 245	1.370218	1.370218 S	0.00	0.0045	0.65	1,000	1.0
	Tethys	294.66	536 x 528 x 526	1.887802	1.887802 S	1.86	0.0000	6.27	1,000	0.9
	Dione	377.40	560	2.736915	2.736915 S	0.02	0.0022	11	1,500	0.7
	Rhea	527.04	764	4.517500	4.517500 S	0.35	0.0010	23.1	1,240	0.7
	Titan	1,221.83	2,575	15.945421		0.33	0.0292	1,345.5	1,881	0.22
	Hyperion	1,481.1	185 x 140 x 113	21.276609	Chaotic	0.43	0.1042	0.2	1,500	0.3
	Iapetus	3,561.3	718	79.330183	79.330183 S	14.72	0.0283	15.9	1,020	0.05 (0.5?)
Irregular Satellites	Kiviuq	11,370	ab. 7	449		48.7	0.33			0.06
Irregular Satellites	Ijiraq	11,440	ab. 5	451		49.1	0.32			0.06
Phoebe (regular satellite)	Phoebe	12,952	115 x 110 x 105	550.48R	0.4	175.3	0.1633	0.072	1,300	0.08
Irregular Satellites (continued)	Paaliaq	15,200	ab. 10	687		47.2	0.36			0.06
	Skadi	15,650	ab. 3	729R		148.5	0.27			0.06
	Albiorix	16,390	ab. 13	738		34.0	0.48			0.06
	Erriapo	17,610	ab. 4	871		33.5	0.47			0.06
	Siarnaq	18,160	ab. 16	893		45.6	0.29			0.06
	Tarvos	18,240	ab. 7	926		34.9	0.54			0.06
	Mundilfari	18,710	ab. 3	951R		169.4	0.21			0.06
	S/2003 S 1	18,720	ab. 3	956R		134.6	0.35			0.06
	Suttung	19,470	ab. 3	1,017R		175.8	0.11			0.06
	Thrym	20,470	ab. 3	1,089R		175.0	0.47			0.06
	Ymir	23,100	ab. 8	1,312R		173.1	0.33			0.06
Additional Finds	20 new moons were found by October 2019, similar in size at about five kilometers in diameter, and a majority -- 17 -- in a retrograde orbit. That retrograde motion indicates they were likely once part of a larger moon that was shattered
Uranus (total: 27)
Inner Satellites	Cordelia (6)	49.77	20	0.335034		0.08	0.0003			0.07
	Ophelia (6)	53.79	21	0.376400		0.10	0.0099			0.07
	Bianca	59.17	27	0.434579		0.19	0.0009			0.07
	Cressida	61.78	40	0.463570		0.01	0.0004			0.07
	Desdemona	62.68	32	0.473650		0.11	0.0001			0.07
	Juliet	64.35	47	0.493065		0.07	0.0007			0.07
	Portia	66.09	68	0.513196		0.06	0.0000			0.07
	Rosalind	69.94	36	0.558460		0.28	0.0001			0.07
	S/2003 U2	74.80	6 (5?)	0.618055
	Belinda	75.26	40	0.623527		0.03	0.0001			0.07
	S/1986 U10	76.4	20	0.637500 (0.6156 d)		0.00	0.00
	Puck	86.01	81	0.761833		0.32	0.0001			0.07
	S/2003 U1	97.70	8 (5?)	0.922916
Major Satellites	Miranda	129.39	240 x 234.2 x 232.9	1.413479	1.413479 S	4.22	0.0027	0.66	1,200	0.27
	Ariel	191.02	581.1 x 577.9 x 577.7	2.520379	2.520379 S	0.31	0.0034	13.5	1,670	0.35
	Umbriel	266.30	584.7	4.144177	4.144177 S	0.36	0.0050	11.7	1,400	0.19
	Titania	435.91	788.9	8.705872	8.705872 S	0.14	0.0022	35.2	1,710	0.28
	Oberon	583.52	761.4	13.463239	13.463239 S	0.10	0.0008	30.1	1,630	0.25
Irregular Satellites	S/2001 U3	5,835	6	266.6		147.6	0.143
	Caliban	7,230	48	579.5R		140.88	0.159			0.07
	Stephano	8,002	10	676.5R		144.06	0.230			0.07
	Trinculo	8,571	10	758.1R		166.33	0.208
	Sycorax	12,179	95	1,283.4R		159.40	0.522			0.07
	S/2003 U3	14,688	5.5	1,695	.	50.70	0.783
	Prospero	16,418	15	1,992.8R		151.91	0.443			0.07
	Setebos	17,459	15	2,202.3R		158.17	0.588			0.07
	S/2001 U2	21,000	6	2,823.4		167.30	0.426
Neptune (total: 13)
	Naiad	48.227	29	0.294396		4.74	0.0003			0.06
	Thalassa	50.075	40	0.311485		0.21	0.0002			0.06
	Despina	52.526	74	0.334655		0.07	0.0001			0.06
	Galatea	61.953	79	0.428745		0.05	0.0001			0.06
	Larissa	73.548	104 x 89	0.554654		0.20	0.0014			0.06
	Proteus (a tiny 20-mile (about 34-km) across moon named Hippocamp, is close to Proteus and likely a chipped-off piece of the larger moon that resulted from a collision with a comet billions of years ago)	117.647	218 x 208 x 201	1.122315		0.04	0.0004			0.06
	Triton	354.76	1,353.4	5.876854 R	5.876854 S	157.345	0.000016	214	2,050	0.77
	Nereid	5,513.4	170	360.13619		7.23	0.7512	0.2	1,000	0.4
	S/2002 N1	15,686	20 (25? 30.5?)	1,874.8		134.1	0.572
	S/2002 N2	22,337	20 (15?)	2,925.6		52.74	0.137
	S/2002 N3	22,613	20 (15? 19?)	2,980.4		39.56	0.416
	S/2003 N1	46,738 (80,000?)	17.5	9,136.1 (or 9,007.1)		137.3	0.450
	S/2002 N4	47,279	30	9,007.1		139.3	0.605

data NASA's National Space Science Data Center (NSSDC)

(1) back when the moon is an irregular body dimensions are the major axis radius, the median axis radius, and the minor axis radius, in this order
(2) back S stands for synchroneous. The rotational period equals the orbital period
(3) back R stands for retrograde. The moon orbits clockwise as seen from the planet's north pole
(4) back Janus and Epimetheus' orbits are separated by a mere 30 miles (50 km). The orbits change from inner to outer each 4 years
(5) back due to its rapid rotation, Mimas has an oblate shape with its diameter at the equator 10 percent larger than at the poles
(6) back Cordelia and Ophelia act as shepherds to Uranus' epsilon ring

Tables Values Specifications

(in alphabetical order)

Albedo: Percentage of light that a planetary surface reflects out of the total light falling on it. Bright, reflective surfaces, such as snow, have a high albedo; dark, absorptive surfaces have a low albedo
Density: Mean density (mass divided by volume) of the moon. Pure ice is approximately at 58 lbs/ft³ (in kg/m³)
Mass: Moon's mass (units at data). Mass is not weight. Mass is the amount of matter in an object. Weight is mass about which gravity is acting. E.g. an object of similar mass (154 lb.) may have a weight of 154 lb. on Earth and of 26 lb only on Moon where gravity is 1/6th the one of Earth. Mass is used to characterize an object's inertia to acceleration, i.e. its resistance to be moved or have its direction changed
Orbital Eccentricity: Measurement of orbit circularity. It is computed by this formula: (aphelion - perihelion) / (2 x semi-major axis). A circular orbit would have a value 0
Orbital Inclination: Angle between moon orbit's plane and planet's equatorial plane (in ° compared to equatorial plane -which is 0)
Orbital Period: Time for moon to complete an orbit around its planet (in days). "R" stands for retrograde. Regular orbital direction is counterclockwise as seen from above planet north pole
Radius: Moon's radius at equator (in km). For irregular bodies data are respectively the major axis radius, the median axis radius, and the minor axis radius, in this order (all these values in km)
Rotational Period: Time for moon to complete a rotation on itself (in days)."R" stands for retrograde. Regular rotational motion is counterclockwise as seen from above moon's north pole. "S" stands for synchronous (rotational period equals orbital period)
Semimajor Axis: Mean distance of the satellite from the planet (semi-major axis) (in km)

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