734 



TABLE 831.— PHYSICAL DATA; PLANETS AND PRINCIPAL SATELLITES 



(From unpublished compilation by G. P. Kuiper and D. L. Harris, Ycrkes Observatory.) 



Mean Mean Surface Velocity Rotation 



Planet or Mass * diameter t density gravity of escape period 



satellite (Earth = 1) (£ = 1) H a O = 1 (£=1) km/sec (days) 



Mercury 0543 .38 5.46 .38 4.3 88.0 



Venus 8136 .967 4.96 .87 10.4 15-30? 



p:arth 1.0000 1.000 5.52 1.00 11.3 1.00 



Mars 1069 .523 4.12 .39 5.1 1.03 



Jupiter 318.35 10.97 1.33 2.65 61.0 .41 



Saturn 95.3 9.03 .71 1.17 36.7 .43 



Uranus 14.58 3.72 1.56 1.05 22.4 .45 



Neptune 17.26 3.38 2.47 ■ 1.23 25.6 .66 



Pluto <.l? .45 <5.S? <.5? <5.3? ? 



Moon 0123 .273 3.33 .16 2.4 27.3 



Jupiter I 0121 .255 4.03 .19 2.5 1.77 



Jupiter II 0079 .226 3.78 .16 2.1 3.55 



Jupiter III 0261 .394 2.35 .17 2.9 7.15 



Jupiter IV 0160 .350 2.06 .13 2.4 16.69 



Titan 0235 .371 2.54 .17 2.8 15.95 



Triton 022 .35.? 2.8? .18? 2.8? 5.88 



* Mass of the Earth is 5.975 X 10" grams; of the Sun 332,488 (1 ± 0.00013) E = 1.987 X 10 33 grams; of the 

 Moon (0.012289 ± 0.000004) E = 7.343 X 10 25 grams. t Equatorial diameter of the Earth = 12,756.78 km; 



polar diameter 12,713.82 km; "mean diameter" 12,742.46 km. See Table 827 



TABLE 832.— PLANETARY TEMPERATURES 



Calculated 



( a 



Measured A B 



Mercury (sunlit side) 690° K 445° K 631° K 



Venus (dark side) 250 



(bright side) 330 327 464 



Earth (mean) 287 277 392 



Moon (center of illuminated hemisphere) 400 277 392 



Mars (warmest portions) 285 222 316 



lupiter 135 122 273 



Saturn 120 90 128 



Uranus less than 90 63 89 



Neptune — 51 72 



All temperatures are given on the absolute scale. To change to centigrade, subtract 273. 

 The column headed "measured" presents values determined by Coblentz and Lampland, 

 and by Pettit and Nicholson. The column headed "A" gives black sphere temperatures; 

 "B" gives these multiplied by V2 or the calculated maximum temperatures of the center 

 of the illuminated hemisphere of atmosphereless black planets. The observed values lie, 

 as expected, between A and B in nearly every case. 



TABLE 833.— PLANETARY ORBITS* 257 



Mean distance to Sun 



Body AT km 



Mercury 387 57.9 t 



Venus 723 108.1 



Earth 1.000 149.5* 



Mars 1.524 227.8 



Jupiter 5.203 777.8 



Saturn 9.539 1426.1 



Uranus 19.191 2869.1 30685.91 84.015 .773 .0472 



Neptune 30.071 4495.6 60187.60 164.788 1.774 .0086 



Pluto 39.457 5898.9 90469.27 247.697 17? 143 .2485 



* Prepared G. P. Kuiper, Yerkes Observatory. 



287 American Ephemeris and Nautical Almanac for 1950. 



t X 101 t Mean distance in km computed from earth's equatorial radius (6378.388 km) and 



solar parallax of 8. "80. Recent determinations by Spencer Jones (Monthly Notices, Roy. Astron. Soc, 

 vol. 101, p. 356, 1941) and Rabe (Astron. Journ., vol. 55, p. 112, 1950) give 8."790 ■+- 0."001 and 

 8."7984 ± 0."0004, respectively. 



SMITHSONIAN PHYSICAL TABLES 



