The planet with the shortest rotation period (shortest day) in the solar system is:

Jupiter spins faster than any other planet in the solar system. It completes one rotation on its axis in about 9 hours and 56 minutes, so a day on Jupiter is less than 10 hours long.

Effects of Jupiter's fast rotation:

Flattened shape: The rapid spin makes Jupiter bulge noticeably at its equator and flatten at its poles. Its equatorial diameter is about 7 percent greater than its polar diameter.

Banded appearance: The fast rotation stretches its clouds into light-coloured zones and dark belts that run parallel to the equator.

Strong magnetic field: Combined with a deep layer of metallic hydrogen, the fast rotation helps produce the strongest planetary magnetic field in the solar system.

Differential rotation:

Since Jupiter is a gas giant with no solid surface, different parts rotate at slightly different speeds. The equatorial regions rotate a little faster than the higher latitudes.

Rotation periods of the planets (approximate):

• Jupiter: 9 hours 56 minutes (shortest).
• Saturn: 10 hours 33 minutes.
• Neptune: about 16 hours.
• Uranus: about 17 hours.
• Earth: 23 hours 56 minutes.
• Mercury: about 59 Earth days.
• Venus: about 243 Earth days (longest).

Revolution of Jupiter:

• Although its day is short, Jupiter takes about 11.86 Earth years to complete one revolution around the Sun.
• Its average distance from the Sun is about 778 million km.

General pattern:

• The giant outer planets rotate much faster than the small inner planets.
• This is believed to be related to the way they gathered angular momentum while forming from a rotating disc of gas.

Why not the other options?

• ✗Mercury takes about 59 Earth days to rotate once.
• ✗Earth takes about 24 hours (more precisely 23 hours 56 minutes with respect to the stars).
• ✗Uranus takes about 17 hours.