Which planet in the solar system has the shortest year?

The planet with the shortest year in the solar system is Mercury. A "year" for a planet refers to the time it takes to complete one full orbit around the Sun. Mercury's orbit is the fastest due to its proximity to the Sun.

Mercury takes approximately 88 Earth days to complete one orbit. This rapid orbital period is a result of its close distance to the Sun, which exerts a stronger gravitational pull, causing Mercury to travel at a higher velocity than the other planets.

In contrast, Venus, Earth, and Mars take longer periods to orbit the Sun. Venus, for instance, has a year that lasts about 225 Earth days, Earth takes 365 days, and Mars takes about 687 days. These longer periods are due to their greater distances from the Sun, which result in slower orbital velocities. Thus, Mercury's unique position and motion in the solar system give it the shortest year of all the planets.