Astronomy for Young Folks

Table II

The Satellites of the Solar System

Name	Apparent Magnitude	Mean Distance from Planet’s Center, in miles	Diameter in miles	Period of Revolution	Discoverer	Year of Discovery
THE EARTH
Moon		238,857	2160	27 days, 7 hours, 43 minutes
MARS
1. Phobos	14	5,850	10?	0 days, 7 hours, 39 minutes	Asaph Hall	1877
2. Deimos	13	14,650	10?	1 day, 6 hours, 17 minutes	Asaph Hall	1877
JUPITER
v.	13	112,500	100?	0 day, 11 hours, 57 minutes	Barnard	1892
i.	6.5	261,000	2452	1 day, 18 hours, 28 minutes	Galileo	1610
ii.	6.5	415,000	2045	3 days, 13 hours, 14 minutes	Galileo	1610
iii.	6	664,000	3558	7 days, 3 hours, 43 minutes	Galileo	1610
iv.	7	1,167,000	3345	16 days, 16 hours, 32 minutes	Galileo	1610
vi.	14	7,372,000	small	266 days, 0 hours, 0 minutes	Perrine	1904
vii.	16	7,567,900	very small	276 days, 16 hours, 5 minutes	Perrine	1905
viii.	17	15,600,000	very small	789 days, 0 hours, 0 minutes	Melotte	1908
ix.	19	18,900,000	20?	3 years	Nicholson	1914
SATURN
1. Meimas	15	117,000	600	0 days, 22 hours, 37 minutes	Herschel	1789
2. Enceladus	14	157,000	800	1 day, 8 hours, 53 minutes	Herschel	1789
3. Tethys	11	186,000	1200	1 day, 21 hours, 18 minutes	Cassini	1684
4. Dione	11	238,000	1100	2 days, 17 hours, 41 minutes	Cassini	1684
5. Rhea	10	332,000	1500	4 days, 12 hours, 25 minutes	Cassini	1672
6. Titan	9	771,000	3000	15 days, 22 hours, 41 minutes	Huygens	1655
7. Hyperion	16	934,000	500	21 days, 6 hours, 39 minutes	Bond	1848
8. Japetus	11	2,225,000	2000	79 days, 7 hours, 54 minutes	Cassini	1671
9. Phoebe	17	8,000,000	200?	546 days, 12 hours, 0 minutes	W.H. Pickering	1898
10. Themis	17	906,000	?	20 days, 20 hours, 24 minutes	W.H. Pickering	1905
URANUS
1. Ariel	15	120,000	500	2 days, 12 hours, 29 minutes	Lassell	1851
2. Umbriel	16	167,000	400	4 days, 3 hours, 28 minutes	Lassell	1851
3. Titania	13	273,000	1000	8 days, 16 hours, 56 minutes	Herschel	1787
4. Oberon	14	365,000	800	13 days, 11 hours, 7 minutes	Herschel	1787
NEPTUNE
1. Nameless	13	221,500	2000	5 days, 21 hours, 3 minutes	Lassell	1846

RINGS OF SATURN

Name	Width, in miles	Distance of Inner Edge from Surface of Saturn, in miles	Distance of Outer Edge from Surface of Saturn, in miles	Diameter of Ring System from outer edge to outer edge, 172,500 miles. Thickness of Ring System, about one hundred miles. Size of Individual Moonlets, probably less than three miles in diameter.
Dark or Crape Ring	10,900	5,900	16,800
Bright Ring	18,000	16,800	34,800
Cassini’s Division	2,200	34,800	37,000
Outer Ring	11,000	37,000	48,000