Jupiter

Jupiter: Jupiter is the fifth planet from the sun and is the largest planet in the Solar System. It is a gas giant with a mass slightly less than one-thousandth of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn, Uranus and Neptune. Together, these four planets are sometimes referred to as the outer planets. Jupiter is primarily composed of hydrogen with a quarter of its mass being helium; it may also have a rocky core of heavier elements. The outer atmosphere is visibly segregated into several bands at different latitudes, resulting in turbulence and storms along their interacting boundaries. A result is the Great Red Spot, a giant storm that is known to have existed since at least the 17th century when it was first seen by telescope. Jupiter also has at least 63 moons, including the four large moons called the Galilean moons that were first discovered by Galileo Galilei in 1610. Ganymede, the largest of these moons, has a diameter greater than that of the planet Mercury. Jupiter is composed primarily of gaseous and liquid matter. It has a diameter of 142,984 km at its equator. The density of Jupiter, 1.326 g/cm³, is the second highest of the gas giant planets. However, the density is lower than any of the four terrestrial planets.  Jupiter's upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium by percent volume or fraction of gasmolecules. Thus the atmosphere is approximately 75% hydrogen and 24% helium by mass, with the remaining one percent of the mass consisting of other elements.