Moons Jupiter

1 moons

1.1 galilean moons
1.2 classification
1.3 planetary rings

moons

jupiter has 69 known natural satellites. of these, 53 less 10 kilometres in diameter , have been discovered since 1975. 4 largest moons, visible earth binoculars on clear night, known galilean moons , io, europa, ganymede, , callisto.

galilean moons

the moons discovered galileo—io, europa, ganymede, , callisto—are among largest satellites in solar system. orbits of 3 of them (io, europa, , ganymede) form pattern known laplace resonance; every 4 orbits io makes around jupiter, europa makes 2 orbits , ganymede makes one. resonance causes gravitational effects of 3 large moons distort orbits elliptical shapes, because each moon receives tug neighbors @ same point in every orbit makes. tidal force jupiter, on other hand, works circularize orbits.

the eccentricity of orbits causes regular flexing of 3 moons shapes, jupiter s gravity stretching them out approach , allowing them spring more spherical shapes swing away. tidal flexing heats moons interiors friction. seen dramatically in extraordinary volcanic activity of innermost io (which subject strongest tidal forces), , lesser degree in geological youth of europa s surface (indicating recent resurfacing of moon s exterior).

classification

before discoveries of voyager missions, jupiter s moons arranged neatly 4 groups of four, based on commonality of orbital elements. since then, large number of new small outer moons has complicated picture. there thought 6 main groups, although more distinct others.

a basic sub-division grouping of 8 inner regular moons, have circular orbits near plane of jupiter s equator , thought have formed jupiter. remainder of moons consist of unknown number of small irregular moons elliptical , inclined orbits, thought captured asteroids or fragments of captured asteroids. irregular moons belong group share similar orbital elements , may have common origin, perhaps larger moon or captured body broke up.

planetary rings

the rings of jupiter

jupiter has faint planetary ring system composed of 3 main segments: inner torus of particles known halo, relatively bright main ring, , outer gossamer ring. these rings appear made of dust, rather ice saturn s rings. main ring made of material ejected satellites adrastea , metis. material fall moon pulled jupiter because of strong gravitational influence. orbit of material veers towards jupiter , new material added additional impacts. in similar way, moons thebe , amalthea produce 2 distinct components of dusty gossamer ring. there evidence of rocky ring strung along amalthea s orbit may consist of collisional debris moon.