Jupiter

Jupiter is the fifth <a href="/facts/Planet/rbPjE6Bx">planet</a> from the <a href="/facts/Sun/CadPCVHh">Sun</a> and the <a href="/facts/List_of_Solar_System_objects_by_size/Aob1rVgh">largest in the Solar System</a>. It is a <a href="/facts/Gas_giant/pmF6KztG">gas giant</a> with a <a href="/facts/Jupiter_mass/EtLUmeEN">mass</a> more than 2.5 times that of all the other planets in the <a href="/facts/Solar_System/QIcLSazQ">Solar System</a> combined and slightly less than one-thousandth the mass of the Sun. Its diameter is 11 times that of <a href="/facts/Earth/HLLmDfj0">Earth</a> and a tenth that of the Sun. Jupiter orbits the Sun at a distance of 5.20 <a href="/facts/Astronomical_unit/gjsbu5xU">AU</a> (778.5 <a href="/facts/Gigametre/YzL1bHGX">Gm</a>), with an <a href="/facts/Orbital_period/94f56uh2">orbital period</a> of 11.86 <a href="/facts/Julian_year_(astronomy)/EVdRNUe3">years</a>. It is the <a href="/facts/List_of_brightest_natural_objects_in_the_sky/6lWwSlUH">third-brightest natural object</a> in the Earth's <a href="/facts/Night_sky/IM1PakDh">night sky</a>, after the <a href="/facts/Moon/zKHqEMPb">Moon</a> and <a href="/facts/Venus/pADnueP6">Venus</a>, and has been observed since <a href="/facts/Prehistoric_times/52D6oKM4">prehistoric times</a>. Its name derives from that of <a href="/facts/Jupiter_(god)/JPetM2m9">Jupiter</a>, the chief deity of <a href="/facts/Ancient_Roman_religion/QrNwmgPM">ancient Roman religion</a>.
Jupiter was the first of the Sun's planets to form, and its inward migration during the primordial phase of the Solar System affected much of the formation history of the other planets. <a href="/facts/Jupiter%2527s_atmosphere/50sQ1eB2">Jupiter's atmosphere</a> consists of 76% <a href="/facts/Hydrogen/BoYHjl0J">hydrogen</a> and 24% <a href="/facts/Helium/yRul93TG">helium</a> by mass, with a denser interior. It contains trace elements and compounds like <a href="/facts/Carbon/ukrgQexo">carbon</a>, <a href="/facts/Oxygen/acyn6o8r">oxygen</a>, <a href="/facts/Sulfur/IK0amTfM">sulfur</a>, <a href="/facts/Neon/5bF1FwGL">neon</a>, <a href="/facts/Ammonia/MtLtJFtz">ammonia</a>, <a href="/facts/Water_vapour/DX5IUFG0">water vapour</a>, <a href="/facts/Phosphine/aYysn5TS">phosphine</a>, <a href="/facts/Hydrogen_sulfide/UbCqjMMk">hydrogen sulfide</a>, and <a href="/facts/Hydrocarbon/Dcg95Ju5">hydrocarbons</a>. Jupiter's helium abundance is 80% of the Sun's, similar to <a href="/facts/Saturn/D54LcGJ9">Saturn</a>'s composition.
The outer atmosphere is divided into a series of latitudinal bands, with turbulence and storms along their interacting boundaries; the most obvious result of this is the <a href="/facts/Great_Red_Spot/8gbPpAJB">Great Red Spot</a>, a giant storm that has been recorded since 1831. Because of its rapid rotation rate, one turn in ten hours, Jupiter is an <a href="/facts/Oblate_spheroid/GJyyLxQ7">oblate spheroid</a>; it has a slight but noticeable 6.5% bulge around the equator compared to its poles. Its internal structure is believed to consist of an outer mantle of fluid <a href="/facts/Metallic_hydrogen/Wc4P3R6I">metallic hydrogen</a> and a diffuse inner core of denser material. The ongoing contraction of Jupiter's interior generates more heat than the planet receives from the Sun. Jupiter's <a href="/facts/Magnetic_field/Ta8Ev588">magnetic field</a> is the strongest and second-largest contiguous structure in the Solar System, generated by <a href="/facts/Eddy_current/KvHNx1v7">eddy currents</a> within the fluid, metallic hydrogen core. The <a href="/facts/Solar_wind/BvuB3dT8">solar wind</a> interacts with the <a href="/facts/Magnetosphere/BXzgPoPy">magnetosphere</a>, extending it outward and affecting Jupiter's orbit.
At least <a href="/facts/Moons_of_Jupiter/Rq3GMt28">97 moons</a> orbit the planet; the <a href="/facts/Galilean_moons/aN6tLUFc">four largest moons</a>—<a href="/facts/Io_(moon)/p3Uc8FmK">Io</a>, <a href="/facts/Europa_(moon)/2A9nleK3">Europa</a>, <a href="/facts/Ganymede_(moon)/AmKsF10c">Ganymede</a>, and <a href="/facts/Callisto_(moon)/et0eIutu">Callisto</a>—orbit within the magnetosphere and are visible with common binoculars. Ganymede, the largest of the four, is larger than the planet <a href="/facts/Mercury_(planet)/lVa1GIyX">Mercury</a>. Jupiter is surrounded by a faint system of <a href="/facts/Planetary_ring/KNCgIIX7">planetary rings</a>. The <a href="/facts/Rings_of_Jupiter/pnojBLSG">rings of Jupiter</a> consist mainly of dust and have three main segments: an inner <a href="/facts/Torus/J9SkaV1W">torus</a> of particles known as the halo, a relatively bright main ring, and an outer gossamer ring. The rings have a reddish colour in visible and near-infrared light. The age of the ring system is unknown, possibly dating back to Jupiter's formation.
In 1610 <a href="/facts/Galileo_Galilei/98VT2z3v">Galileo Galilei</a> published the first telescopic study of Jupiter. Since 1973, Jupiter has been <a href="/facts/List_of_missions_to_the_outer_planets/HHIUgK4W">visited by</a> nine <a href="/facts/Robotic_spacecraft/Frlbbkvu">robotic probes</a>: seven <a href="/facts/Flyby_(spaceflight)/BtJe76fP">flybys</a> and two dedicated orbiters, with two more en route. <a href="/facts/Jupiter_analogue/YYBeXKhe">Jupiter-like exoplanets</a> have also been found in other solar systems.

Jupiter open-in-new

Jupiter