Proteus (muin)
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.jpg) Voyager 2 eemage (1989) | |
| Discovery | |
|---|---|
| Discovered bi | Voyager 2 Stephen P. Synnott |
| Discovery date | 16 Juin 1989 |
| Designations | |
| Adjectives | Protean |
| Orbital chairactereestics[1] | |
| Epoch 18 August 1989 | |
| Periapsis | 117584±10 km |
| Apoapsis | 117709±10 km |
| 117647±1 km (4.75 RN) | |
| Eccentricity | 0.00053±0.00009 |
| 1.12231477±0.00000002 d | |
Average orbital speed | 7.623 km/s |
| Inclination | 0.524° (to Neptune equator) 0.026°±0.007° (tae local Laplace plane) |
| Satellite o | Neptune |
| Pheesical chairacteristics | |
| Dimensions | 424 × 390 × 396 km[2][lower-alpha 1] |
Mean radius | 210±7 km[5] |
| Vollum | (3.4±0.4)×107 km3[2] |
| Mass | 4.4×1019 kg (7.3672×10−6 Earths)[lower-alpha 2] |
Mean density | ≈ 1.3 g/cm³ (estimate)[5] |
| 0.07 m/s2[lower-alpha 3] | |
| 0.17 km/s[lower-alpha 4] | |
| synchronous[2] | |
| zero[2] | |
| Albedo | 0.096[5][6] |
| Temperatur | ≈ 51 K mean (estimate) |
| 19.7[5] | |
Proteus (Greek: Πρωτεύς), an aw kent as Neptune VIII, is the seicont-lairgest Neptunian muin, and Neptune's largest inner satellite.
Notes[eedit | eedit soorce]
- ↑ In the earlier papers slichtly different dimensions war reportit. Thomas an Veverka in 1991 reportit 440×416×404 km.[2][3] Croft in 1992 reportit 430×424×410 km.[4] The difference is caused bi the uise o different sets o eemages an bi the fact that the shape o Proteus is nae descrived well bi a triaxial ellipsoid.[2]
- ↑ The mass wis calculated bi multiplyin the vollum frae Stooke (1994)[2] bi the assumed density o 1,300 kg/m3. If ane uises slichtly lairger dimensions frae the earlier papers the mass will increase tae 5×1019 kg.[5]
- ↑ Surface gravity derived frae the mass m, the gravitational constant G an the radius r: Gm/r2.
- ↑ Escape velocity derived frae the mass m, the gravitational constant G an the radius r: √2Gm/r.
References[eedit | eedit soorce]
- ↑ Jacobson, R. A.; Owen, W. M., Jr. (2004). "The orbits of the inner Neptunian satellites from Voyager, Earthbased, and Hubble Space Telescope observations". Astronomical Journal. 128 (3): 1412–1417. Bibcode:2004AJ....128.1412J. doi:10.1086/423037.CS1 maint: ref=harv (link)
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Stooke, Philip J. (1994). "The surfaces of Larissa and Proteus". Earth, Moon, and Planets. 65 (1): 31–54. Bibcode:1994EM&P...65...31S. doi:10.1007/BF00572198.CS1 maint: ref=harv (link)
- ↑ Williams, Dr. David R. (2008-01-22). "Neptunian Satellite Fact Sheet". NASA (National Space Science Data Center). Retrieved 2008-12-12.
- ↑ Croft, S. (1992). "Proteus: Geology, shape, and catastrophic destruction". Icarus. 99 (2): 402–408. Bibcode:1992Icar...99..402C. doi:10.1016/0019-1035(92)90156-2.
- ↑ 5.0 5.1 5.2 5.3 5.4 "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 2010-10-18. Retrieved 2011-10-11.
- ↑ Karkoschka, Erich (2003). "Sizes, shapes, and albedos of the inner satellites of Neptune". Icarus. 162 (2): 400–407. Bibcode:2003Icar..162..400K. doi:10.1016/S0019-1035(03)00002-2.CS1 maint: ref=harv (link)