Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, and slightly less than one one-thousandth the mass of the Sun. Jupiter is surrounded by a faint planetary ring system and has a powerful magnetosphere, the second largest contiguous structure in the Solar System (after the heliosphere). Size and Mass: Jupiter is a gas giant, meaning it consists mostly of hydrogen and helium gas. It is approximately 11 times wider than Earth and over 300 times more massive. In fact, Jupiter's mass is greater than that of all the other planets in the solar system combined. Great Red Spot: One of the most iconic features of Jupiter is the Great Red Spot, a massive storm system that has been raging for at least 350 years. It is so large that it could fit several Earths within its boundaries. While it has been shrinking over the years, it remains a prominent feature on the planet's surface. Moons: Jupiter has an extensive system of moons, with over 80 known satellites. The four largest moons, known as the Galilean moons, are Io, Europa, Ganymede, and Callisto. These moons are some of the largest in the solar system and were discovered by Galileo Galilei in 1610. Magnetic Field: Jupiter boasts an incredibly strong magnetic field, which is the strongest of any planet in the solar system. This magnetic field creates intense radiation belts around the planet and poses a significant challenge to spacecraft exploring the Jovian system. Rapid Rotation: Jupiter is a fast spinner, completing a full rotation on its axis in just under 10 hours. This rapid rotation leads to the planet's distinct flattened appearance at the poles and bulging at the equator. Lack of a Solid Surface: Unlike terrestrial planets like Earth, Jupiter lacks a solid surface. Instead, its composition transitions from a gaseous atmosphere into denser and more metallic hydrogen and helium deeper within the planet. Interior Heat: Jupiter emits more heat than it receives from the Sun, primarily due to the heat generated during its formation and the slow contraction of its interior. This excess heat contributes to the planet's strong and dynamic weather systems. Exploration: Several spacecraft have been sent to study Jupiter, including the Galileo spacecraft, which orbited the planet from 1995 to 2003, and the Juno spacecraft, which arrived in orbit in 2016. These missions have provided valuable insights into Jupiter's atmosphere, magnetic field, and interior structure. Role in the Solar System: Jupiter plays a crucial role in the dynamics of the solar system. Its immense gravitational influence helps to stabilize the orbits of other planets and prevents many potential threats, such as asteroid impacts, from reaching the inner solar system. Future Exploration: Future missions, such as the European Space Agency's JUpiter ICy moons Explorer (JUICE) and NASA's Europa Clipper, are planned to further explore Jupiter and its intriguing moons. These missions aim to uncover more about the planet's composition, magnetosphere, and the potential habitability of its icy moons.