Page:Encyclopædia Britannica, Ninth Edition, v. 2.djvu/848

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782
ASTRONOMY
[theoretical—

General Elements of the Solar System.      Epoch, January 0A (noon), 1850.

General Elements of the Solar System. Epoch, January Q d (noon), 1850. Name. Mercury,.. Venus, Earth, Mars, Asteroids, . Jupiter,.... Saturn, .... Uranus, ... Neptune,.. Symbol Distance from the Sun in Miles. Mean dis tanceEarth s as 1. Mean. Greatest. Least. 35,392,000 42,669,000 28,115,000 0-387099 66,134,000 66,586,000 65,682,000 0723332 91,430,000 92,963,000 89,897,000 1-000000 139,311,000 152,304,000 126,318,000 1-523691 200,000,000 215,000,000 164,000,000 2-200000 to to to to 315,000,OOD 370,000,000 276,000,000 3-500000 475,692,000 498,639,000 452,745,000 5-202798 872,137,000 920,973,000 823,301,000 9-538852 1,753,869,000 1,835,561,000 1,672,177,000 19-182639 2,745,998,000 2,771,190,000 2,720,806,000 30-036970 Eccentricity. 0-205618 0-006833 0-016771 0-093262 0-04 to 3-t 0-048239 0-055990 0-046578 0-008720 Sidereal Revolution in Days. 87- 224- 365 686- 1200- to 2400- 4332 10759 30686 60126 9693 7008 2564 9797 5848 2198 8208 7200 Synodical Revolution in Days. 115-877 583-920 779-936 398-867 378-090 369-656 367-488 Mean daily Motion. 14732-419 5767-668 3548-193 1886-518 299-129 120-455 42-233 21-406 Name. Mercury, Venus, . . . Earth Mars, Asteroids, Jupiter,. . . Saturn, .. Uranus, .. Neptune, , Longitude of Perihelion. 75 7 O O 129 23 56-0 100 21 40-0 333 17 50-5 11 54 53-1 90 6 12-0 168 16 45-0 47 14 37-3 Annual Variation. + 5-81 - 3-24 + 11-24 + 15-46 + 6-65 + 19-31 + 2-28 Unknown Same re ferred to Venial Equinox. + 55-91 -0 47-14 + 1 1 34 + 1 5-56 + 056-75 + 1 9 41 + 052-38 Unknown Longitude of Ascending Node. 46 33 75 19 3-3 4-2 48 22 44-8 98 54 20-5 112 21 44-8 73 14 14-4 130 6 51-6 Annual Variation. -10-07 -20-50 -50-10 -25-22 - 15-90 -19-54 -36-05 Unknown Same re ferred to Vernal Equinox. + 40-03 + 29-60 + 24 -88 + 34-20 + 30-56 + 14-05 Unknown Inclination of Orbit. 7 8-2 3 23 30-8 1 51 5-1 1 is io-s 2 29 28-1 46 29-9 1 46 59-0 Annual Variation. + 0-18 + 0-07 - 0-01 - 0-23 -0-15 + 0-03 Unknown Diameter. Apparent at Mean Distance from Earth. In Miles. 6-90 16-94 37-91 17-52 3-91 2-80 3,058 7,510 7,926 4,363 84,846 70,136 33,247 37,276 Name. Volume. Earth s as 1. Mass. Earth s as I. Density. Earth s as 1. Light received fi om Sun at Perihelion. Aphelion Compres sion. Gravity at Surface. Earth s asl. Bodies fall in one Second. Time of Rotation upon Axis. Trelination of Equator to Orbit. Longitude of the Vernal Equinox. Mercury, , Venus, .... Earth, ... Mars, Asteroids, Jupiter,. . . Saturn, .. Uranus, .. Neptune, 0-058 0-855 1-000 0-168 1233 : 205 696-685 74-199 105-575 0-065 0-885 1-000 0-108 300 : 860 89-692 12-650 16-773 1-12 1-03 1-00 0-70 0-24 0-13 0-17 0-16 10-58 1-94 1-034 0-524 0-0408 0-0123 0-0027 0-0011 4-59 1-91 0-907 0-360 0-0336 0-0099 0-0025 0-0011 0-432 0-982 1-000 0-387 2-611 1-141 0-716 0-756 ft. 6-953 15-805 IG 095 6-229 45 : 024 18-364 11-524 12-163 h. in. s. 24 5 28 ? 23 21 15 ? 23 56 4 24 37 3 9 55 26 10 29 17 9 30 ?? 50 + ? 23 27 24 28 27 3 5 30 26 48 40 180 79 15 314 " 167 4 5 165 25 ? 175 40 ?



Elements of the Moon.   Epoch, 1st January 1801.
(Earth's equatorial diameter is taken as 7925·8 miles.)

Mean longitude of moon at epoch 118 17 8" 3 Do. node 13 53 17"7 Do. perigee .266 10 7" 5 Mean distance from the earth (earth s radius 1) 60-2634 Same in miles 238,818 Maximum distance in miles 252,948 Minimum do. do 221,593 Eccentricity of orbit 05490S07 Mean equatorial horizontal lunar parallax- Maximum do. do. Minimum do . do. Moon s mean apparent diameter .... Moon s maximum do. Moon s minimum do. Moon s diameter in miles..., 57 2" -7 1 28 7 -8 53 51" -5 31 5" l 33 30"-1 29 20" -9 2159-6 Moon s surface in square miles 14,600,000 Moon s diameter (earth s equatorial diameter as 1).... 2725 Earth s equatorial diameter (moon s as 1) 3 "670 Moon s surface (earth s as 1) 0742 Earth s surface (moon s as 1) 13 471 Moon s volume (earth s as 1} - 0202 Earth s volume (moon s as 1) 49-441 Moon s mass (earth s as 1) 01228 Earth s mass (moon s as 1) 81 -40 Density (earth s as 1) 0-60736 Density (water s as 1, and earth s assumed=5 7) 3-46 Gravity, or weight of one terrestrial pound 0-16547 Bodies tall in one second in feet 2 65 Inclination of axis 1 30 ll"-3 Mean inclination of orbit Maximum do. do Minimum do. do Synodical revolution in days. Sidereal do. do. Tropical do. do Anomalistic do. do Nodical do. do Maximum evection Maximum variation Maximum annual equation Maximum libration in latitude Do. do. in longitude Maximum total libration (from earth s centre) Maximum diurnal libration Surface of moon never seen (whole as 10,000, and diurnal libration neglected) Surface seen at one time or other do. do Do. never seen, if diurnal libration be taken into account Do. seen at one time or other do Mean revolution of nodes (retrograde) in days Do. do. do. in years Mean regression of nodes per annum Mean regression of node between successive conjunc tions of sun and rising node Mean interval between such conjunctions in days Mean revolution of perigee (advancing) in days Do. do. in years Mean advance of perigee per annum Do. do. between successive conjunc tions of sun and perigee Mean interval between such conjunctions in days...*. 5 8 5 13 5 3 29-53059 27-32166 27-32156 27-55460 27-21222 1 20 29" -9 35 42"-0 11 12"-0 6 44 7 45 10 16 1 1 28" 8 4193 5802 4111 5S89 6793-391 18-5997 19 2V 18" -3 18 22 3" -2 346-607 3232-575 8-8505 40 40 31" -1 45 51 23"7

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