Jupiter is the fifth planet from the Sun and the largest planet in the Solar System.
Key facts about Jupiter
It is a gas giant with a mass more than 2.5 times that of all the other planets in the Solar System combined and slightly less than one-thousandth the mass of the Sun.
Jupiter is at an average distance of 778 million kilometers from the Sun. From this distance, it takes sunlight 43 minutes to travel from the Sun to Jupiter.
Jupiter has the shortest day in the solar system. One day on Jupiter takes only about 10 hours (the time it takes for Jupiter to rotate or spin around once), and Jupiter makes a complete orbit around the Sun (a year in Jovian time) in 11.86 years or approximately 12 Earth years (4,333 Earth days).
It is the third brightest natural object in the Earth’s night sky, after the Moon and Venus.
The ongoing contraction of Jupiter’s interior generates more heat than the planet receives from the Sun.
Jupiter has been observed since prehistoric times and its name derives from that of Jupiter, the chief deity of ancient Roman religion.
Jupiter was the first of the Sun’s planets to form. Thus, Jupiter is the oldest planet, forming from the dust and gases left over from the Sun’s formation 4.5 billion years ago.
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Size of Jupiter
It is the largest planet in the Solar System, with a diameter of 142,984 km at its equator, giving it a volume 1,321 times that of the Earth.
Its diameter is eleven times that of Earth, and a tenth that of the Sun.
Its average density, 1.326 g/cm3, is lower than those of the four terrestrial planets.
Shape of Jupiter
Because of its rapid rate of rotation, one turn in ten hours, Jupiter is an oblate spheroid; it has a slight but noticeable bulge around the equator.
Atmosphere of Jupiter
Jupiter’s atmosphere consists of 76% hydrogen and 24% helium by mass, with a denser interior.
It contains trace elements and compounds like carbon, oxygen, sulfur, neon, ammonia, water vapour, phosphine, hydrogen sulfide, and hydrocarbons.
Jupiter’s helium abundance is 80% of the Sun’s, similar to Saturn’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 Great Red Spot, a giant storm that has been recorded since 1831.
Jupiter’s magnetic field is the strongest and second-largest contiguous structure in the Solar System, generated by eddy currents within the fluid, metallic hydrogen core.
The solar wind interacts with the magnetosphere, extending it outward and affecting Jupiter’s orbit.
Temperature at Jupiter
Jupiter’s stripes and swirls are beautiful, but they are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium.
The mean temperature on Jupiter is -110°C.
Rings of Jupiter
Jupiter is surrounded by a faint system of planetary rings that were discovered in 1979 by Voyager 1 and further investigated by the Galileo orbiter in the 1990s.
The Jovian ring system consists mainly of dust and has three main segments: an inner torus 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.
How the rings of Jupiter formed?
Jupiter’s rings likely formed when chunks of rock or ice crashed into the small moons that now reside within the rings. The collisions blasted dust into space that then encircled the planet.
Why Jupiter doesn’t have rings like Saturn?
Saturn is famous for its brilliant, icy rings. But all of the gas giants in the solar system (Saturn, Neptune, Uranus and Jupiter) have rings. Unlike Saturn’s rings, Jupiter’s are thin and wispy. And while Galileo first saw Saturn’s rings in 1610, Jupiter’s rings were not discovered until the 1970s, when the Voyager spacecraft visited the planet.
Because it’s bigger, Jupiter ought to have larger, more spectacular rings than Saturn has. But Jupiter’s massive moons prevent their formation.
Saturn’s rings are largely made of ice, some of which may have come from comets, which are also largely made of ice. If moons are massive enough, their gravity can toss the ice out of a planet’s orbit, or change the orbit of the ice enough so that it collides with the moons.
The Galilean moons of Jupiter, one of which is the largest moon in our solar system, would very quickly destroy any large rings that might form. Massive planets form massive moons, which prevents them from having substantial rings.
Internal structure of Jupiter
Its internal structure is believed to consist of an outer mantle of fluid metallic hydrogen and a diffuse inner core of denser material.
Moons of Jupiter
At least 95 moons orbit the planet; the four largest moons – Io, Europa, Ganymede, and Callisto – orbit within the magnetosphere, and were discovered by Galileo Galilei in 1610.
Ganymede, the largest of the four, is larger than the planet Mercury.
Galilean moons
The famous Italian astronomer Galileo Galilei studied Jupiter extensively in the 1600s and discovered its four largest moons: Io, Europa, Ganymede and Callisto.
These moons are unique and of great interest to scientists because:
Io is the most volcanically active body in the entire solar system.
Europa is an ocean world covered by a thick crust of ice. It is one of the best candidates for finding extraterrestrial life in our solar system.
Ganymede is huge – it’s even larger than the planet Mercury – and is the only moon known to have its own magnetic field.
Callisto has the oldest and most heavily cratered surface in the solar system, which acts as a great time capsule for the history of the solar system.
Since 1973, Jupiter has been visited by nine robotic probes: seven flybys and two dedicated orbiters, with two more en route.
External link: https://science.nasa.gov/jupiter/
