Star-Land

Table of Useful Astronomical Facts

The sun’s mean distance from the earth is 92,700,000 miles; his diameter is 865,000 miles, and he rotates in a period between 25 and 26 days.

The moon’s mean distance from the earth is 238,000 miles; the diameter of the moon is 2160 miles, and the time of revolution round the earth is 27.322 days.

The Planets

	Mean Distance from the Sun in Millions of Miles.	Periodic Time of Revolution in Days.	Diameter of Planet in Miles.	Axial Rotation.
				Hrs.	Mins.	Secs.
Mercury	35.9	87.969	2,992	Uncertain.
Venus	67.0	224.70	7,660	Uncertain.
Earth	92.7	365.26	7,918	23	56	4.09
Mars	141	686.98	4,200	24	37	22.7
Jupiter	482	4,332.6	85,000	9	55	—
Saturn	884	10,759	71,000	10	14	23.8
Uranus	1,780	30,687	31,700	Unknown.
Neptune	2,780	60,127	34,500	Unknown.

The Satellites of Mars

Name.	Mean Distance from Centre of Mars.	Periodic Time.
		Hrs.	Mins.	Secs.
Phobos	5,800 miles.	7	39	14
Deimos	14,500 ″	30	17	54

The Satellites of Jupiter

Name.	Mean Distance from Centre of Jupiter.	Periodic Time.
		Days	Hrs.	Mins.	Secs.
I	262,000 miles.	1	18	27	34
II	417,000 ″	3	13	13	42
III	664,000 ″	7	3	42	33
IV	1,170,000 ″	16	16	32	11
V	112,400 ″	—	11	57	(?)

The Satellites of Saturn

Name.	Mean Distance from Centre of Saturn.	Periodic Time.
		Days	Hrs.	Mins.	Secs.
Mimas	118,000 miles.	0	22	37	27.9
Enceladus	152,000 ″	1	8	53	6.7
Tethys	188,000 ″	1	21	18	25.7
Dione	241,000 ″	2	17	41	8.9
Rhea	337,000 ″	4	12	25	10.8
Titan	781,000 ″	15	22	41	25.2
Hyperion	946,000 ″	21	7	7	40.8
Iapetus	2,280,000 ″	79	7	54	40.4

A ninth satellite was discovered in August, 1898, by Prof. W. H. Pickering, but its mean distance and periodic time have not yet been determined with precision.

The Satellites of Uranus

Name.	Mean Distance from Centre of Uranus.	Periodic Time. Days.
Ariel	119,000 miles.	2.520383
Umbriel	166,000 ″	4.144121
Titania	272,000 ″	8.705897
Oberon	363,000 ″	13.463269

The Satellite of Neptune

Name.	Mean Distance from Centre of Neptune.	Periodic Time. Days.
Anonymous	220,000 miles.	5.87690