- For the asteroid, see 9 Metis. Asteroids, sometimes called Minor planets or planetoids', are bodies—primarily of the inner Solar System —that are smaller than planets but For the moon of Jupiter, see Metis (moon. TemplateInfobox Planet.
 Image of Metis was taken by Galileo's solid state imaging system between November 1996 and June 1997. Galileo was an Unmanned spacecraft sent by NASA to study the Planet Jupiter and its moons Named after the Astronomer | |
Discovery | |
|---|---|
| Discovered by | S. Synnott |
| Discovery date | March 4, 1979 |
| Periapsis | 127,974 km[1] |
| Apoapsis | 128,026 km[1] |
| Mean orbit radius | 128,000 km (1. Stephen P Synnott is a Voyager scientist who discovered several moons of Jupiter, Saturn, Uranus, and Neptune. Events 51 - Nero, later to become Roman Emperor, is given the title Princeps iuventutis (head of the youth Year 1979 ( MCMLXXIX) was a Common year starting on Monday (link displays the 1979 Gregorian calendar) In Physics, an orbit is the gravitationally curved path of one object around a point or another body for example the gravitational orbit of a planet around a star In Celestial mechanics, an apsis, plural apsides (ˈæpsɨdɪːz is the point of greatest or least distance of the Elliptical orbit of an object from The kilometre ( American spelling: kilometer) symbol km is a unit of Length in the Metric system, equal to one thousand In Celestial mechanics, an apsis, plural apsides (ˈæpsɨdɪːz is the point of greatest or least distance of the Elliptical orbit of an object from The kilometre ( American spelling: kilometer) symbol km is a unit of Length in the Metric system, equal to one thousand Remote Authentication Dial In User Service ( RADIUS) is a networking protocol that provides centralized access authorization and accounting management for people or computers The kilometre ( American spelling: kilometer) symbol km is a unit of Length in the Metric system, equal to one thousand 792 RJ)[2][3] |
| Eccentricity | 0. In Astrodynamics, under standard assumptions, any Orbit must be of Conic section shape 0002[2][3] |
| Orbital period | 0. The orbital period is the time taken for a given object to make one complete Orbit about another object 294780 d (7 h 4. 5 min)[2][3] |
| Average orbital speed | 31. The orbital speed of a body generally a Planet, a Natural satellite, an artificial satellite, or a Multiple star, is the speed at which it 501 km/s[1] |
| Inclination | 0. Inclination in general is the Angle between a Reference plane and another plane or axis of direction 06° (to Jupiter's equator)[2][3] |
| Satellite of | Jupiter |
Physical characteristics | |
| Dimensions | 60×40×34 km³[4] |
| Mean radius | 21. A natural satellite or moon is a Celestial body that Orbits a Planet or smaller body which is called the primary. 5 ± 2. 0 km[4] |
| Volume | ~42,700 km³ |
| Mass | 3. The volume of any solid plasma vacuum or theoretical object is how much three- Dimensional space it occupies often quantified numerically CM3 redirects here If you were looking for the 3rd game in the Cooking Mama series abbreviated as CM3 see here. Mass is a fundamental concept in Physics, roughly corresponding to the Intuitive idea of how much Matter there is in an object 6 ×1016 kg[1] |
| Mean density | 0. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 86 g/cm³ (assumed) |
| Equatorial surface gravity | 0. The surface gravity, g, of an astronomical or other object is the Gravitational acceleration experienced at its surface 005 m/s² (0. 0005 g)[1] |
| Escape velocity | 0. In Physics, escape velocity is the speed where the Kinetic energy of an object is equal to the magnitude of its Gravitational potential energy 012 km/s[1] |
| Rotation period | synchronous |
| Axial tilt | zero[4] |
| Albedo | 0. The rotation period of an astronomical object is the time it takes to complete one revolution around its Axis of rotation relative to the background stars In Astronomy, synchronous rotation is a planetological term describing a body orbiting another where the orbiting body takes as long to rotate In Astronomy, axial tilt is the Inclination angle of a planet's rotational axis in relation to its orbital plane. The albedo of an object is the extent to which it diffusely reflects light from the sun 061 ± 0. 003[5] |
| Temperature | ~123 K |
Metis (mee'-təs, IPA: /ˈmiːtɪs/, Greek: Μήτις) or Jupiter XVI, is Jupiter's innermost moon. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly
Metis was discovered in 1979 by Stephen P. Synnott in images taken by the Voyager 1 probe. Stephen P Synnott is a Voyager scientist who discovered several moons of Jupiter, Saturn, Uranus, and Neptune. The Voyager 1 spacecraft is a 722-kilogram robotic Space probe of the outer Solar system and beyond launched September 5, [6] Its provisional designation was S/1979 J 3. A provisional designation in astronomy is the naming convention applied to Astronomical objects immediately following their discovery [7][6] In 1983 it was officially named after the mythological Metis, a Titaness who was the first wife of Zeus (the Greek equivalent of Jupiter). In Greek mythology, Metis (Μῆτις was of the Titan generation and like several primordial figures an Oceanid, in the sense that Metis was born of In Greek mythology, the Titans ( Greek: Tītā́n; plural Tītânes) were a race of powerful Deities that ruled during the legendary Zeus (zjuːs in Greek: nominative: Zeús /zdeús/ genitive: Diós; Modern Greek /'zefs/ in Greek mythology [8]
Contents |
Physical characteristics
Metis has an irregular shape and measures 60×40×34 km across. [4] The bulk composition and mass of Metis are not known, but assuming that its mean density is like that of Amalthea (~0. 86 g/cm³),[9] its mass can be estimated as ~7×1016 kg. Amalthea's density implies that that moon is composed of water ice with a porosity of 10-15%, and Adrastea may be similar. Ice is a Solid phase, usually crystalline, of a Non-metalic substance that is liquid or gas at Room temperature, such as Ammonia Porosity is a measure of the void spaces in a material and is measured as a fraction between 0–1 or as a Percentage between 0–100% [9]
The surface of Metis is heavily cratered. It is dark and appears to be reddish in color. There is a substantial asymmetry between leading and trailing hemispheres: the leading hemisphere is 1. 3 times brighter than the trailing one. The asymmetry is probably caused by the higher velocity and frequency of impacts on the leading hemisphere, which excavate a bright material (presumably ice) from the interior of the moon. [5]
Orbit
Metis is the innermost of Jupiter's four small inner moons. It orbits Jupiter at a distance of ~128,000 km (1. 79 Jupiter radii) within the planet's Main Ring. The planet Jupiter has a system of rings known as the rings of Jupiter or the Jovian ring system. Its orbit has very small eccentricity (~0. In Astrodynamics, under standard assumptions, any Orbit must be of Conic section shape 0002) and inclination (~ 0. Inclination in general is the Angle between a Reference plane and another plane or axis of direction 06°) relative to the equator of Jupiter. [2][3]
Due to tidal locking, Metis rotates synchronously with its orbital period, keeping one face always looking toward the planet. A separate article treats the phenomenon of Tidal resonance in Oceanography. Its long axis is aligned towards Jupiter, this being the lowest energy configuration. [4][3]
The orbit of Metis lies inside Jupiter's synchronous orbit radius (as does Adrastea's), and as a result, tidal forces are slowly causing its orbit to decay, so that it will one day impact into Jupiter. A synchronous orbit is an Orbit in which an orbiting body (usually a Satellite) has a period equal to the average rotational period of the body being orbited (usually Adrastea (, or as in Greek Αδράστεια also known as Jupiter XV, is the second by distance and the smallest of the four inner moons of Jupiter Tidal acceleration is an effect of the Tidal forces between an orbiting Natural satellite ( i If its density is similar to Amalthea's then its orbit would actually lie within the fluid Roche limit. Determining the Roche limit The Roche limit depends on the rigidity of the satellite In any case, however, since it is not breaking up, it must still lie outside its rigid Roche limit. Determining the Roche limit The Roche limit depends on the rigidity of the satellite [3]
Relationship with Jupiter's rings
Metis's orbit lies ~1000km within the main ring of Jupiter. The planet Jupiter has a system of rings known as the rings of Jupiter or the Jovian ring system. It orbits within a ~500km wide 'gap' or 'notch' in the ring. [10][3] The gap is clearly somehow related to the moon but the origin of this connection has not been established. Metis supplies a significant part of the Main Ring’s dust. The planet Jupiter has a system of rings known as the rings of Jupiter or the Jovian ring system. [11] This material appears to consist primarily of material that is ejected from the surfaces of Jupiter's four small inner satellites by meteorite impacts. It is easy for the impact ejecta to be lost from the satellites into space because the satellites' surfaces lie fairly close to the edge of their Roche spheres due to their low density. A Hill sphere is roughly the volume around an Astronomical body (such as a Planet) where it dominates in attraction of Satellites to that body rather [3]
Exploration
The photographs taken by Voyager 1 showed Metis only as a dot, and hence knowledge about Metis was very limited until the arrival of the Galileo spacecraft. Galileo was an Unmanned spacecraft sent by NASA to study the Planet Jupiter and its moons Named after the Astronomer Galileo imaged almost all of the surface of Metis and put constraints on its composition. [4]
See also
References
- ^ a b c d e f Calculated on the basis of other parameters
- ^ a b c d e Evans, M. In Astronomy, an inner moon is a Natural satellite following a prograde, low inclination Orbit inwards of the large satellites of The planet Jupiter has a system of rings known as the rings of Jupiter or the Jovian ring system. 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.
- ^ a b c d e f g h i Burns, J. A. ; D. P. Simonelli & M. R. Showalter 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, <http://www.astro.umd.edu/~hamilton/research/preprints/BurSimSho03.pdf>
- ^ a b c d e f Thomas, P. C. ; Burns, J. A. ; Rossier, L. ; et. al. (1998). "The Small Inner Satellites of Jupiter". ICARUS 135: 360–371. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ a b Simonelli, D. P. ; Rossiery, L. ; Thomas, P. C. ; et. al. (2000). "Leading/Trailing Albedo Asymmetries of Thebe, Amalthea, and Metis". ICARUS 147: 353–365. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ a b Synnott, S. P. (1981). "1979J3: Discovery of a Previously Unknown Satellite of Jupiter". Science 212 (4501): 1392.
- ^ IAUC 3507: Satellites of Jupiter 1980 August 26 (discovery)
- ^ IAUC 3872: Satellites of Jupiter and Saturn 1983 September 30 (naming the moon)
- ^ a b Anderson, J. Year 1980 ( MCMLXXX) was a Leap year starting on Tuesday (link displays the 1980 Gregorian calendar) Events 1071 - Battle of Manzikert: The Seljuk Turks defeat the Byzantine Army at Manzikert. Year 1983 ( MCMLXXXIII) was a Common year starting on Saturday (link displays the 1983 Gregorian calendar) Events 1399 - Henry IV is proclaimed King of England. 1744 - France and Spain defeat the D. ; Johnson, T. V. ; Shubert, G. ; et. al. (2005). "Amalthea’s Density Is Less Than That of Water". Science 308: 1291–1293. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ Ockert-Bel, M. E. ; Burns, J. A. ; Daubar, I. J. ; et. al. (1999). "The Structure of Jupiter’s Ring System as Revealed by the Galileo Imaging Experiment". ICARUS 138: 188–213. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ Burns, J. A. ; Showalter, M. R. ; Hamilton, D. P. ; et. al. (1999). "The Formation of Jupiter's Faint Rings". Science 284: 1146-1150. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
External links
Metis Profile by NASA's Solar System Exploration
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