Jupiter is mainly composed of hydrogen and helium just like a star.

The Great Red Spot is a giant storm that is known to have existed since at least the 17th century when it was first seen by telescope.

Jupiter has 79 moons, including four large moons discovered by Galileo in 1610.

Ganymede has a diameter greater than that of the planet Mercury.

Despite its massive size, Jupiter has the shortest day of all the planets. It turns on its axis once every 9 hours and 55 minutes.

Jupiter has faint rings composed of tiny rock fragments and dust. They do not contain ice, like Saturn's rings. Jupiter's rings are continuously losing material and being resupplied with new dust from micrometeors hitting Jupiter's four inner moons (Metis, Adrastea, Amalthea, and Thebe).

Io is the most volcanically active body in the Solar System.

Although Jupiter is a great deal larger in size, its surface gravity is just 2.4 times that of the surface gravity of Earth because Jupiter is made mostly of gases. If you weigh 100 pounds on Earth, you would weigh 240 pounds on Jupiter (assuming you could find someplace to stand!)

Scientists believe that there is a liquid ocean somewhere around 100 km (60 miles) beneath the thick, icy crust of Europa.The tidal affects between Europa and Jupiter are thought to heat the water and keep it in liquid form. If this ocean is proven to exist, Europa may be one of the most promising places in our solar system, beyond Earth, to search for life.

It rotates counter-clockwise, with a period of about six Earth days or fourteen Jovian days.