start of chapter two 2
DESCRIPTION
What is an encyclopedia with an example of planetsTRANSCRIPT
Chapter 2 101Reading an Encyclopedia articleEncyclopedias have heading and sub-headings
They have an outline and often a summary some also have further study
They have a lot of graphs, charts, tables drawing etc.
In example Wikipedia below they have bold prints and italics e.g. planetary-mass object, or planemo. words to show what theses mean or highlight these words.
List of gravitationally rounded objects of the Solar SystemFrom Wikipedia, the free encyclopedia (Redirected from Table of planets in the solar system)Jump to: navigation, search
In 2006, the International Astronomical Union (IAU) defined a planet as a body in orbit around the Sun that was large enough to have achieved hydrostatic equilibrium and to have cleared the neighbourhood around its orbit.[1] An object in hydrostatic equilibrium is one that is large enough for its gravity to have overcome its internal rigidity, and so relax into a rounded (ellipsoidal) shape. The practical meaning of "cleared the neighborhood" is that a planet is comparatively massive enough for its gravitation to control the orbits of all objects in its vicinity. By the IAU's definition, there are eight planets in the Solar System. Those objects in orbit around the Sun that have achieved hydrostatic equilibrium but have not cleared their neighborhoods are called dwarf planets, and the remainder are termed small Solar System bodies. In addition, the Sun itself and 19 known natural satellites are also massive enough to have achieved hydrostatic equilibrium.[2] Apart from the Sun, these bodies are included in the term planetary-mass object, or planemo. All
known planetary-mass objects in the Solar System, as well as the Sun, are listed below, along with a sample of the largest objects whose shape has yet to be accurately determined. The Sun's orbital characteristics are listed in relation to the Galactic Center. All other objects are listed in order of their distance from the Sun. In total, the Solar System has 33 objects that have been observationally confirmed to be in hydrostatic equilibrium: 1 star, 8 planets, 5 dwarf planets and 19 satellites.
Contents [hide]
1 Sun 2 Planets
3 Dwarf planets
4 Satellite planemos
5 Largest likely dwarf planets
6 See also
7 Notes
o 7.1 Unless otherwise cited: [ac]
o 7.2 Manual calculations (unless otherwise cited)
o 7.3 Individual calculations
o 7.4 Other notes
8 References
[edit] SunThe Sun is a G-type main-sequence star. It contains almost 99.9 percent of all the mass in the Solar System.[3]
Sun [4]
Astronomical symbol [q] Mean distance
from Galactic Centerkm
light years~2.5×1017
~26,000
Mean radius km :E[f]
696,000109
Surface area km2 6.0877×1012
:E[f] 11,990
Volume km3
:E[f]1.4122×1018
1,300,000
Mass kg :E[f]
1.9891×1030
332,946Density g/cm3 1.409
Equatorial gravity m/s 2 274.0Escape velocity km/s 617.7Rotation period days[g] 25.38
Orbital period about Galactic Center[5] million years 225–250Mean orbital speed[5] km/s ~220
Axial tilt [i] to the ecliptic deg. 7.25Axial tilt [i] to the galactic plane deg. 67.23
Mean surface temperature K 5,778Mean coronal temperature [6] K 1–2×106
Photospheric composition H, He, O, C, Fe, S
[edit] Planets
Key*terrestrial planet
°gas giant
Planets both are large enough to have achieved hydrostatic equilibrium and have cleared their neighborhoods of similar objects. There are four terrestrial planets and four gas giants in the Solar System. The latter combined comprise more than 99 percent of the mass in the Solar System excluding that of the Sun.
*Mercury [7]
*Venus [ 8]
*Earth [ 9]
*Mars [1 0]
°Jupiter [1 1]
°Saturn [12 ]
°Uranus [ 13]
°Neptune [14]
Astronomical symbol [q]
Mean distance km 57,909, 108,208 149,597 227,936 778,412,0 1,426,725 2,870,97 4,498,25
from Sun AU175
0.38709893
,9300.72333
199
,8901.00000
011
,6401.52366
231
105.203363
01
,4009.537070
32
2,20019.19126
393
2,90030.06896
348
Equatorial radius
km :E[f
]
2,439.64
0.3825
6,051.59
0.9488
6,378.11
3,397.00
0.53226
71,492.6811.209
60,267.149.449
25,557.25
4.007
24,766.36
3.883
Surface areakm² :E[f
]
75,000,000
0.1471
460,000,000
0.9010
510,000,000
1
140,000,000
0.2745
64,000,000,000125.5
44,000,000,00086.27
8,100,000,00015.88
7,700,000,00015.10
Volumekm3
:E[f
]
6.083×1010
0.056
9.28×1011
0.87
1.083×1012
1
1.6318×1011
0.151
1.431×101
5
1,321.3
8.27×1014
763.59
6.834×1013
63.086
6.254×1013
57.74
Masskg
:E[f
]
3.302×1023
0.055
4.8690×1024
0.815
5.9742×1024
1
6.4191×1023
0.107
1.8987×1027
318
5.6851×1026
95
8.6849×1025
14
1.0244×1026
17
Density g/cm3 5.43 5.24 5.515 3.940 1.33 0.70 1.30 1.76
Equatorial gravity
m/s 2 3.70 8.87 9.81 3.71 23.12 10.44 8.69 11.00
Escape velocity km/s 4.25 10.36 11.18 5.02 59.54 35.49 21.29 23.71
Rotation period[g]
days
58.646225
−243.0187[h]
0.99726968
1.02595675 0.41354 0.44401 −0.71833
[h] 0.67125
Orbital period[g] years
0.2408467
0.61519726
1.0000174
1.8808476
11.862615
29.447498
84.016846
164.79132
Mean orbital speed
km/s 47.8725 35.0214 29.7859 24.1309 13.0697 9.6724 6.8352 5.4778
Eccentricity 0.20563069
0.00677323
0.01671022
0.09341233
0.04839266
0.05415060
0.04716771
0.00858587
Inclination [f] deg. 7.00 3.39 0[9] 1.85 1.31 2.48 0.76 1.77Axial tilt [i] deg. 0.0 177.3 23.44 25.19 3.12 26.73 97.86 29.58
Mean surface temperature K 440–
100 730 287 227 152 [j] 134 [j] 76 [j] 72 [j]
Mean air temperature [k] K 288 165 135 76 73
Atmospheric composition
He Na+ P+ CO2 N2 N2 O2
CO2 N2 Ar H2 He H2 He H2 He
CH4
H2 He CH4
Number of known moons [v] 0 0 1 2 66 or 67 62 27 13
Rings? No No No No Yes Yes Yes Yes
Planetary discriminant [l] [o] 9.1×104 1.35×10
6 1.7×106 1.8×105 6.25×105 1.9×105 2.9×104 2.4×104
[edit] Dwarf planets
Key†
Ceres‡
plutoid
Dwarf planets are large enough to have achieved hydrostatic equilibrium, but have not cleared their neighbourhoods of similar objects. There are currently five dwarf planets recognized by the IAU in this category. Ceres orbits in the asteroid belt, between the orbits of Mars and Jupiter. The others orbit beyond Neptune and are sub-classified as plutoids.
†Ceres [15] ‡Pluto [16] ‡Haumea [17] ‡Makemake [1
8]‡Eris [19]
Astronomical symbol [q] Minor planet number 1 134340 136108 136472 136199
Mean distancefrom Sun
kmAU
413,700,000
2.766
5,906,380,000
39.482
6,484,000,000
43.335
6,850,000,000
45.792
10,210,000,000
67.668
Mean radius km :E[f]
4710.0738
1,148.070.180
5750.1537[20]
750+200−100
0.12[20]
1,2000.19[20]
Volume km3
:E[f]4.37×108
0.0005[b]6.33×109
0.0071.3–1.6×109
0.001[y]1.8×109
0.002[b]7.23×109
0.008[b]
Surface area km² :E[f]
2,800,0000.0055[a]
17,000,0000.0333
6,800,0000.0133[z]
7,000,0000.015[a]
18,000,0000.0353[a]
Mass kg :E[f]
9.5×1020
0.000161.3×1022
0.0022
4.01 ± 0.04×1021
0.0007[21]
3×1021
0.00051.7×1022
0.0028[22]
Density g/cm3 2.08 2.0 2.6–3.3[23] 2.0[c] 2.25[c]
Equatorial gravity m/s 2 0.27[d] 0.60 0.44[d] 0.5[d] ~0.8[d]
Escape velocity km/s [e] 0.51 1.23 0.84 0.8 1.37
Rotation period[g] days 0.3781 −6.38718[h] 0.167 ? ?
Orbital period[g] years 4.599 247.92065 285.4 309.9 557Mean orbital speed km/s 17.882 4.7490 4.484[o] 4.4[o] 3.436[n]
Eccentricity 0.080 0.24880766 0.18874 0.159 0.44177Inclination [f] deg. 10.587 17.14175 28.19 28.96 44.187Axial tilt [i] deg. 4 119.61 ? ? ?
Mean surface temperature [w] K 167[24] 40[25] <50[26] 30 30
Atmospheric composition H2O, O2 N2, CH4 N2, CH4.[27] N2, CH4[28]
Number of known moons [v] 0 5 2 [29] 0[30] 1 [31] Planetary discriminant [l] [o] 0.33 0.077 0.023 0.02 0.10
[edit] Satellite planemos
Key€
Satellite of Earth
₤
Satellite of Jupiter
$
Satellite of Saturn
₩
Satellite of Uranus
₦
Satellite of Neptune
¶
Satellite of Pluto
See also: List of moons
There are 19 natural satellites in the Solar System that are known to be massive enough to have achieved hydrostatic equilibrium, what Alan Stern calls satellite planets. Another satellite, the Neptunian moon Proteus, is not in hydrostatic equilibrium, but is slightly larger than Mimas, the smallest of the 19 satellite planemos.[ab] Satellites are listed first in order from the Sun, and second in order from their parent body.
€Moon [32] ₤Io [33] ₤Europa [34]
₤Ganymede [35]
₤Callisto [36]
$Mimas [p]
$Enceladus [p]
$Tethys [p]
$Dione [p]
$Rhea [ p]
Astronomical symb ol [q]
Mean distancefrom primary: km 384,399 421,6
00670,90
01,070,40
01,882,700
185,520
237,948
294,619
377,396
527,108
Mean radiuskm :E[f
]
1,737.10.273
1,8150.286
1,5690.245
2,634.10.413
2,410.3
0.378
198.30
0.031
252.10.04
5330.083
561.70.088
764.30.12
Surface area [a] km² :E[f
37,930,000
41,910,000
30,900,000
87,000,000
73,000,000
490,000
799,000
4,940,000
3,965,000
7,337,000
] 0.074 0.082 0.061 0.143 0.143 0.001 0.0016 0.01 0.0078
0.0144
Volume [b] km3
:E[f
]
2.2×1010
0.02
2.53×1010
0.02
1.59×1010
0.07
7.6×1010
0.15
5.9×1010
0.05
3.3×107
0.00003
6.7×107
0.00006
6.3×108
0.0006
7.4×108
0.0007
1.9 ×109
0.0017
Masskg
:E[f
]
7.3477×1022
0.0123
8.94×1022
0.015
4.80×1022
0.008
1.4819×1023
0.025
1.0758×1023
0.018
3.75×1019
0.000006
1.08×1020
0.000018
6.174×1020
0.00132
1.095×1021
0.0003
2.306×1021
0.0004
Density [c] g/cm3 3.3464 3.528 3.01 1.936 1.83 1.15 1.61 0.98 1.48 1.23
Equatorial gravity [d]
m/s 2 1.622 1.796 1.314 1.428 1.235 0.063
6 0.111 0.145 0.231 0.264
Escape velocity [e]
km/s 2.38 2.56 2.025 2.741 2.440 0.159 0.239 0.393 0.510 0.635
Rotation period days[g]
27.321582
(sync)[m]
1.7691378(sync)
3.551181
(sync)
7.154553
(sync)
16.68902
(sync)
0.942422
(sync)
1.370218
(sync)
1.887802
(sync)
2.736915
(sync)
4.518212
(sync)Orbital period about primary
days[g] 27.32158 1.769
1383.5511
817.15455
316.689
020.942422
1.370218
1.887802
2.736915
4.518212
Mean orbital speed[o]
km/s 1.022 17.34 13.740 10.880 8.204 14.32 12.63 11.35 10.03 8.48
Eccentricity 0.0549 0.0041 0.009 0.0013 0.0074 0.020
2 0.0047 0.02 0.002 0.001
Inclination to primary's equator
deg.
18.29–28.58 0.04 0.47 1.85 0.2 1.51 0.02 1.51 0.019 0.345
Axial tilt [i] [u] deg. 6.68 0 0 0–
0.33[37] 0 0 0 0 0 0
Mean surface temperature [w] K 220 130 102 110[38] 134 64 75 64 87 76
Atmospheric composition
H He Na+
K+ ArSO2
[39] O2[40] O2
[41] O2 CO2
[42]
H2O, N2,
CO2, CH4
[43]
Rings? No No No No No No No No No Yes?
$Titan [p] $Iapetu
s [p] ₩Miran
da [r] ₩Ariel [
r]
₩Umbriel [r]
₩Titania [r]
₩Oberon [r]
₦Triton [44]
¶Charon [16]
Mean distancefrom primary: km 1,221,8
703,560,8
20 129,390 190,900 266,000 436,30
0583,51
9354,75
9 17,536
Mean radius km :E[f]
2,5760.404
735.600.115
235.80.037
578.90.091
584.70.092
788.90.124
761.40.119
1353.40.212
603.50.095
Surface area [a] km² :E[f]
83,000,000
0.163
6,700,000
0.013
700,0000.0014
4,211,300
0.008
4,296,000
0.008
7,820,000
0.015
7,285,000
0.014
23,018,000
0.045
4,580,000
0.009
Volume [b] km3
:E[f]
7.16×1010
0.066
1.67×109
0.0015
5.5×107
0.00005
8.1×108
0.0008
8.4×108
0.0008
2.06×109
0.0019
1.85×109
0.0017
1×1010
0.00958
9.2×108
0.00085
Mass kg :E[f]
1.3452×1023
0.023
1.8053×1021
0.0003
6.59×1019
0.00001
1.35×1021
0.00022
1.2×102
1
0.0002
3.5×1021
0.0006
3.014×1021
0.00046
2.14×1022
0.00358
1.52×1021
0.00025
Density [c] g/cm3 1.88 1.08 1.20 1.67 1.40 1.72 1.63 2.061 1.65
Equatorial gravity[d] m/s 2 1.35 0.22 0.08 0.27 0.23 0.39 0.35 0.78 0.28
Escape velocity [e] km/s 2.64 0.57 0.19 0.56 0.52 0.77 0.73 1.46 0.58
Rotation period days[g]
15.945(sync)[m]
79.322(sync)
1.414(sync)
2.52(sync)
4.144(sync)
8.706(sync)
13.46(sync)
5.877(sync)
6.387(sync)
Orbital period about primary days 15.945 79.322 1.4135 2.520 4.144 8.706 13.46 −5.877[
h] 6.387
Mean orbital speed[o]
km/s 5.57 3.265 6.657 5.5089
8 4.66797 3.644 3.152 4.39 0.2
Eccentricity 0.0288 0.0286 0.0013 0.0012 0.005 0.0011 0.0014 0.00002 0.0022
Inclination to primary's equator deg. 0.33 14.72 4.22 0.31 0.36 0.14 0.10 157 ?
Axial tilt [i] [u] deg. 0 0 0 0 0 0 0 0 ?Mean surface tem
perature [w] K 93.7[45] 130 59 58 61 60 61 38 [46] 53
Atmospheric composition
N2, CH4
[47]N2,
CH4[48]
[edit] Largest likely dwarf planetsMain article: List of possible dwarf planets
These trans-Neptunian objects are theoretically large enough to be dwarf planets. Dozens more could have been included.[2] Both Quaoar and Orcus have known moons that have allowed the mass of the systems to be determined. Both are more massive than the 5×1020 kg recommendation of the IAU 2006 draft proposal as sufficient for classification as a dwarf planet.[49]
Orcus [ 50]
Ixion [5 1]
Varuna [52]
2005 UQ513
[5
3]
Quaoar [54]
2002 TC302
[5
5]
2007 OR10
[56]
2007 UK126
[57
]
2005 QU182
[58
]
Sedna [5 9]
Minor-planet number 90482 28978 20000 20242
1 50000 84522 225088 229762 303775 90377
Semi-major axis
kmAU
5,896,946,00
039.419
5,935,999,00
039.68
6,451,398,00
043.13
6,479,089,38
043.31
6,493,296,00
043.6
8,264,380,00
055.24
10,072,433,34
067.33
11,032,000,00
073.74
16,991,749,80
0113.58
78,668,000,000525.86
Mean radius [s] km :E[
f]
4730.0742
4020.063
~3500.06
4600.072[aa
]
4220.066
~5500.094
~6400.10
4400.07[aa]
5250.08[aa]
~5000.08
Surface area [a]
km²
:E[
f]
2,811,462
0.0055
2,030,775
0.00398
1,091,000
0.00636
2,659,044
0.0052
2,237,870
0.00439
4,521,600
0.00887
6,157,522
0.012
2,432,849
0.005
3,463,606
0.007
3,000,000
0.006
Volume [b]
km3
:E[
f]
443,273,7680.0004
272,123,9510.0002
549,135,7850.0005
407,720,0830.0003
314,793,6490.0002
904,320,0000.0008
1,436,755,0400.001
356,817,9050.0002
606,131,0330.0004
500,000,000
0.0005
Mass [t] kg :E[
f]
6.32×1020[60]
0.0001
5.4×1020
0.00009
5.5×1020
0.00009
8.2×1020
0.0001
(1.3–1.9)×1021[61]
0.0004
1.8×1021
0.0003
2.9×102
1
0.0005
7.1×102
0
0.0001
1.2×102
1
0.0002
1×1021
0.00016
Density [t] g/cm
3
1.5±0.3[60] 2.0 0.9992[
62] 2.0 >2.8[61] 2.0 2.0 2.0 2.0 2.0
Equatorial gravity [d]
m/s 2 0.27 0.22 0.14 0.26 0.24 0.34 <0.39 0.25 0.29 <0.5
Escape velocity [e]
km/s 0.50 0.42 0.38 0.49 0.45 0.63 <0.74 0.46 0.55 <1.0
Rotation period[g]
days ? ? 0.1321
6[62] ? ? ? ? ? ? 0.42[63]
Orbital period[g]
years
247.492 249.95 283.20 285.12 287.97 410.62 552.52 633.28 1,210.5
312,059.
06Mean orbital
speedkm/s 4.68 4.66 4.53 4.52 4.52 3.93 3.63 3.25 2.79 1.04
Eccentricity 0.22552 0.242 0.051 0.145 0.038 0.292 0.5 0.490 0.675 0.855
Inclination [f] deg. 22.5 19.6 17.2 25.69 8 35 30.7 23.37 14.03 11.93
Mean surface temperature [w] K ~42 ~43 ~43 ~41 ~41 ~38 ~30 ~32 ~25 ~12
Number of known moons 1[64] 0 0 0 1[65] 0 0 0 0 0
Planetary discriminant [l] [o] 0.003 0.0027 0.0027 0.003 0.0015 0.335 0.18[x] 0.036[x] 0.007[x] ?[x]
Absolute magnitude (H) 2.30 3.20 3.70 3.40 2.71 3.8 1.7 3.40 3.40 1.58
[edit] See also
Book: Solar System
[edit] Notes
[edit] Unless otherwise cited:[ac]
o. ^ The planetary discriminant for the planets is taken from material published by Stephen Soter.[66] Planetary discriminants for Ceres, Pluto and Eris taken from Soter, 2006. Planetary discriminants of all other bodies calculated from the Kuiper belt mass estimate given by Lorenzo Iorio.[67]
p. ^ Saturn satellite info taken from NASA Saturnian Satellite Fact Sheet.[68]
q. ^ Astronomical symbols for all listed objects except Ceres taken from NASA Solar System Exploration.[69] Symbol for Ceres was taken from material published by James L.
Hilton.[70] The Moon is the only natural satellite with an astronomical symbol, and Pluto and Ceres the only dwarf planets.
r. ^ Uranus satellite info taken from NASA Uranian Satellite Fact Sheet.[71]
s. ^ Radii for plutoid candidates taken from material published by John Stansberry et al.[20]
u. ^ Axial tilts for most satellites assumed to be zero in accordance with the Explanatory Supplement to the Astronomical Almanac: "In the absence of other information, the axis of rotation is assumed to be normal to the mean orbital plane."[72]
v. ^ Natural satellite numbers taken from material published by Scott S. Sheppard.[73]
[edit] Manual calculations (unless otherwise cited)
a. ^ Surface area A derived from the radius using , assuming sphericity.
b. ^ Volume V derived from the radius using , assuming sphericity.
c. ^ Density derived from the mass divided by the volume.
d. ^ Surface gravity derived from the mass m, the gravitational constant G and the radius r: G*m/r2 .
e. ^ Escape velocity derived from the mass m, the gravitational constant G and the radius r: sqrt((2*G*m)/r).
n. ^ Orbital speed is calculated using the mean orbital radius and the orbital period, assuming a circular orbit.
t. ^ Assuming Pluto's density of 2.0
w. ^ Calculated using the formula where Teff =54.8 K at 52 AU, is the geometrical albedo, q=0.8 is the phase integral, and is the distance from the
Sun in AU. This formula is a simplified version of that in section 2.2 of Stansberry, et al., 2007,[20] where emissivity and beaming parameter were assumed equal unity, and was replaced with 4 accounting for the difference between circle and sphere. All parameters mentioned above were taken from the same paper.
aa. ^ Calculated using the formula , where H is the absolute magnitude, p is the geometric albedo and D is the diameter in km, and assuming an albedo of 0.15, as per Dan Bruton.[74]
[edit] Individual calculations
y. ^ Derived from density
z. ^ Surface area was calculated using the formula for a scalene ellipsoid:
where is the modular angle, or
angular eccentricity; and , are the incomplete elliptic integrals of the first and second kind, respectively. The values 980 km, 759 km, and 498 km were used for a, b, and c respectively.
[edit] Other notes
f. ^ Relative to Earth
g. ^ sidereal
h. ^ retrograde
i. ^ The inclination of the body's equator from its orbit.
j. ^ At pressure of 1 bar
k. ^ At sea level
l. ^ The ratio between the mass of the object and those in its immediate neighborhood. Used to distinguish between a planet and a dwarf planet.
m. ^ This object's rotation is synchronous with its orbital period, meaning that it only ever shows one face to its primary.
x. ^ Objects' planetary discriminants based on their similar orbits to Eris. Sedna's population is currently too little-known for a planetary discriminant to be determined.
bb. ^ Proteus average diameter: 210 km;[44] Mimas average diameter: 199 km[68]
cc. ^ "Unless otherwise cited" means that the information contained in the citation is applicable to an entire line or column of a chart, unless another citation specifically notes otherwise.
[edit] References1. ̂ "IAU 2006 General Assembly: Result of the IAU Resolution votes" (Press release).
International Astronomical Union (News Release – IAU0603). 2006-08-24. http://www.iau.org/public_press/news/release/iau0603/. Retrieved 2007-12-31. (orig link)
2. ^ a b Mike Brown. "The Dwarf Planets". CalTech. http://www.gps.caltech.edu/~mbrown/dwarfplanets/. Retrieved 2008-09-25.
3. ̂ M Woolfson (2000). "The origin and evolution of the solar system". Astronomy & Geophysics 41 (1): 1.12. doi:10.1046/j.1468-4004.2000.00012.x.
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