Jupiter

Jupiter is the fifth planet from the Sun, and the largest in the solar system, more than twice as massive as the other planets combined.

Jupiter also is the oldest planet, forming from the dust and gases left over from the Sun's formation 4.5 billion years ago. But it has the shortest day in the solar system, taking only 10.5 hours to spin around once on its axis.

Jupiter took shape along with rest of the solar system about 4.5 billion years ago. Gravity pulled swirling gas and dust together to form this gas giant. Jupiter took most of the mass left over after the formation of the Sun, it has the same ingredients as a star, but it did not grow massive enough to ignite.

Source: NASA