It has to do with the immense gravity of the planet causing it to force itself around itself. It is also a gas giant, and gases move faster than other states.
Jupiter has the shortest "day" of any planet in the solar system.
Jupiter
The approximate day lengths (with "day" defined here as the rotation period of a planet) of the planets in the solar system are:Mercury 1407.5 hoursVenus 2802 hoursEarth 24 hoursMars 24.5 hoursJupiter 10 hoursSaturn 10.5 hoursUranus 17.25 hoursNeptune 16 hoursNote that the number for Uranus is its rotation period BUT Uranus spins "on its side". Thus the time it takes for sunlight to illuminate all parts of the planet depends on its orbital period round the Sun, which is 84 years or 735840 hours.
Jupiter is the fastest spinning planet in our solar system rotating on average once in just under 10 hours.That is very fast especially considering how large Jupiter is. This means that Jupiter has the shortest days of all the planets in the solar system. Since Jupiter is a gas planet, it does not rotate as a solid sphere. Jupiter's equator rotates a bit faster than its polar regions at a speed of 28,273 miles/hour (about 43,000 kilometers an hour).Jupiter's day varies from 9 hours and 56 minutes around the poles to 9 hours and 50 minutes close to the equator.
There is only one "major planet", Jupiter. Jupiter has more mass than all the other planets put together. But we think of our solar system as having eight planets (nine, if you're old like me and still count Pluto). They are, in decreasing size order, Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars and Mercury.
The planets with the shortest days are Jupiter (9 hours and 55 minutes) and Saturn (10 hours and 30 minutes.)
Jupiter - it has the shortest day and the fastest roational speed
Saturn's year lasts 29.5 Earth years, however Saturn's day lasts only 10.6 Earth Hours. That is less than half of one Earth day.
It is a outer planet
Jupiter has the shortest "day" of any planet in the solar system.
Jupiter, with a day being 9.9hrs long. This is followed closely by Saturn, having a day length of just over 10 1/2hrs.
The shortest planetary "day" (period of rotation) is that of the largest planet, Jupiter.With an equatorial rotation speed of over 12.6 km/sec (28,000 mph), Jupiter spins once on its axis every 9.925 Earth hours. (about 9 hours, 55 1/2 minutes)
Jupiter in the planet with the shortest rotation time, with a day approximately 12 hours long.
Of the four inner planets (Mercury, Venus, Earth, and Mars), Earth has the shortest day at 23 hours and 56 minutes sidereal rotation period. That's the "sidereal day". The day that lasts exactly 24 hours is called the "solar day". For both "days", Earth has the shortest day.
A year on Jupiter is the same as 11.86 years on Earth. Jupiter's orbit varies by 76 million kilometers and has two times the mass of all the other objects in the solar system.
Jupiter has the shortest rotational (spin) period, about 9 hours, 55 minutes, 30 seconds.
Jupiter, Saturn Uranus and Neptune all complete one rotation in less than a day.