Adrastea (moon)

Adrastea
	Image of Adrastea taken by Galileo's solid state imaging system between November 1996 and June 1997.
Discovery
Discovered by	David C. Jewitt; G. Edward Danielson
Discovery date	July 8, 1979
Orbital characteristics
Mean orbit radius	129,000 km
Eccentricity	0.0015
Orbital period	0.29826 d (7 h 9.5 min)
Average orbital speed	31.378 km/s
Inclination	0.03° (to Jupiter's equator)
Satellite of	Jupiter
Physical characteristics
Dimensions	20×16×14 km
Mean radius	8.2 ± 2.0 km
Volume	~2,345 km³
Mass	~2×1015 kg
Mean density	0.86 g/cm³ (assumed)
Surface gravity	~0.002 m/s² (0.0004 g)
Escape velocity	~0.008 km/s
Rotation period	synchronous
Axial tilt	zero
Albedo	~0.1 ± 0.045
Temperature	~122 K

Adrastea or Jupiter XV, is the second closest moon to Jupiter. It was found by David C. Jewitt and G. Edward Danielson in Voyager 2 probe photographs taken in 1979 and received the designation S/1979 J 1.^[5]^[6] In 1983, it was named after the mythological Adrastea,^[7] who was a daughter of Jupiter and Ananke.

Adrastea was the first moon to be found from images taken by an interplanetary spacecraft, rather than through telescopic photography.

Physical characteristics

Adrastea is non-spherical and measures 20x16x14 km³ across.^[4] What Adrastea is made of and the mass of Adrastea are not known, but assuming that its mean density is like that of Amalthea (~0.86 g/cm³)^[8] its mass can be estimated at ~2×10¹⁵ kg. Amalthea's density implies that moon is composed of water ice with a porosity of 10-15%, and Adrastea may be similar.^[8]

No surface details of Adrastea are known, due to the low resolution of available images.^[4]

Orbit

Adrastea is the smallest and second closest member of the closer moons to Jupiter. It orbits Jupiter at ~129,000 km (1.806 Jupiter radii) within the planet's Main Ring. The orbital eccentricity of ~0.0015 and inclination of ~ 0.03° relative to the equator of Jupiter are very small.^[2]

Exploration

Adrastea was found in Voyager 1 and 2 images, but appeared only as a dot.^[6] The Galileo spacecraft was able to see its shape, but the images remain poor.^[4]

References

↑ ^1.0 ^1.1 ^1.2 ^1.3 Evans, M. W.; Porco, C. C.; Hamilton, D. P. (2002). "The Orbits of Metis and Adrastea: The Origin and Significance of their Inclinations". Bulletin of the American Astronomical Society. 34: 883. Bibcode:2002DPS....34.2403E.
↑ ^2.0 ^2.1 ^2.2 ^2.3 ^2.4 Burns, J.A.; Simonelli, D.P. & Showalter, M.R. et al. (2004), "Jupiter’s Ring-Moon System", in Bagenal, F.; Dowling, T. E.; McKinnon, W. B., Jupiter: The planet, Satellites and Magnetosphere, Cambridge University Press
↑ ^3.0 ^3.1 ^3.2 ^3.3 ^3.4 Calculated on the basis of other parameters
↑ ^4.0 ^4.1 ^4.2 ^4.3 ^4.4 ^4.5 ^4.6 Thomas, P.C.; Burns, J.A.; Rossier, L.; Simonelli, D.; Veverka, J.; Chapman, C.R.; Klaasen, K.; Johnson, T.V.; Belton, M.J.S. (1998). "The Small Inner Satellites of Jupiter". ICARUS. 135 (2): 360–371. Bibcode:2000Icar..147..353S. doi:10.1006/icar.1998.5976.
↑ IAUC 3454: Editorial Notice 1980 February 25 (discovery)
↑ ^6.0 ^6.1 Jewitt, David C.; Danielson, G. Edward; Synnott, Stephen P. (1979). "Discovery of a New Jupiter Satellite". Science. 206 (4421): 951. doi:10.1126/science.206.4421.951. PMID 17733911. S2CID 6391249.
↑ IAUC 3872: Satellites of Jupiter and Saturn 1983 September 30 (naming the moon)
↑ ^8.0 ^8.1 Anderson, John D.; Johnson, Torrence V.; Schubert, Gerald; Asmar, Sami; Jacobson, Robert A.; Johnston, Douglas; Lau, Eunice L.; Lewis, George; Moore, William B.; Taylor, Anthony; Thomas, Peter C.; Weinwurm, Gudrun (2005). "Amalthea's Density Is Less Than That of Water". Science. 308 (5726): 1291–1293. Bibcode:2005Sci...308.1291A. doi:10.1126/science.1110422. PMID 15919987. S2CID 924257.

Other websites

Adrastea Profile Archived 2013-03-17 at the Wayback Machine by NASA's Solar System Exploration

[Evans2002-1] 1.0 ^1.1 ^1.2 ^1.3 Evans, M. W.; Porco, C. C.; Hamilton, D. P. (2002). "The Orbits of Metis and Adrastea: The Origin and Significance of their Inclinations". Bulletin of the American Astronomical Society. 34: 883. Bibcode:2002DPS....34.2403E.

[Burns2004-2] 2.0 ^2.1 ^2.2 ^2.3 ^2.4 Burns, J.A.; Simonelli, D.P. & Showalter, M.R. et al. (2004), "Jupiter’s Ring-Moon System", in Bagenal, F.; Dowling, T. E.; McKinnon, W. B., Jupiter: The planet, Satellites and Magnetosphere, Cambridge University Press

[stub-3] 3.0 ^3.1 ^3.2 ^3.3 ^3.4 Calculated on the basis of other parameters

[Thomas1998-4] 4.0 ^4.1 ^4.2 ^4.3 ^4.4 ^4.5 ^4.6 Thomas, P.C.; Burns, J.A.; Rossier, L.; Simonelli, D.; Veverka, J.; Chapman, C.R.; Klaasen, K.; Johnson, T.V.; Belton, M.J.S. (1998). "The Small Inner Satellites of Jupiter". ICARUS. 135 (2): 360–371. Bibcode:2000Icar..147..353S. doi:10.1006/icar.1998.5976.

[5] IAUC 3454: Editorial Notice 1980 February 25 (discovery)

[Jewitt1979-6] 6.0 ^6.1 Jewitt, David C.; Danielson, G. Edward; Synnott, Stephen P. (1979). "Discovery of a New Jupiter Satellite". Science. 206 (4421): 951. doi:10.1126/science.206.4421.951. PMID 17733911. S2CID 6391249.

[7] IAUC 3872: Satellites of Jupiter and Saturn 1983 September 30 (naming the moon)

[Anderson2005-8] 8.0 ^8.1 Anderson, John D.; Johnson, Torrence V.; Schubert, Gerald; Asmar, Sami; Jacobson, Robert A.; Johnston, Douglas; Lau, Eunice L.; Lewis, George; Moore, William B.; Taylor, Anthony; Thomas, Peter C.; Weinwurm, Gudrun (2005). "Amalthea's Density Is Less Than That of Water". Science. 308 (5726): 1291–1293. Bibcode:2005Sci...308.1291A. doi:10.1126/science.1110422. PMID 15919987. S2CID 924257.

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v t e Moons of Jupiter
Listed in increasing approximate distance from Jupiter
Inner moons (4)	Metis Adrastea Amalthea Thebe
Galilean moons (4)	Io Europa Ganymede Callisto
Themisto group (1)	Themisto
Himalia group (9)	Leda Ersa S/2018 J 2 Himalia Pandia Lysithea Elara S/2011 J 3 Dia
Carpo group (2)	S/2018 J 4 Carpo
Valetudo group (1)	Valetudo
Ananke group (26)	Euporie Jupiter LV Eupheme S/2021 J 3 Jupiter LII Jupiter LIV Mneme Euanthe S/2003 J 16 Harpalyke Orthosie S/2022 J 3 Helike S/2021 J 2 Praxidike Jupiter LXIV S/2021 J 1 S/2003 J 12 Jupiter LXVIII Thelxinoe Thyone S/2003 J 2 Ananke Iocaste Hermippe Jupiter LXX
Carme group (30)	S/2022 J 1 S/2022 J 2 S/2016 J 3 Pasithee Jupiter LXIX S/2021 J 6 S/2003 J 24 Chaldene Jupiter LXIII Isonoe S/2021 J 4 Kallichore Erinome Kale Eirene Aitne Eukelade Arche Taygete Jupiter LXXII Carme Herse Jupiter LXI Jupiter LI S/2003 J 9 Jupiter LXVI Kalyke S/2018 J 3 S/2021 J 5 S/2003 J 10
Pasiphaë group (18)	Philophrosyne Eurydome Jupiter LVI S/2003 J 4 S/2016 J 4 Jupiter LXVII Hegemone Pasiphaë Sponde Megaclite Cyllene Sinope Jupiter LIX Aoede Autonoe Callirrhoe S/2003 J 23 Kore
Related page	Rings of Jupiter
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