This is much longer than Earth's 24-hour day. Here's why:

* Slow Rotation: Mercury rotates very slowly on its axis.

* Orbital Period: Mercury orbits the Sun very quickly, completing one orbit in only 88 Earth days.

* Tidal Locking: Mercury is tidally locked to the Sun, meaning it rotates once for every two orbits around the Sun. This results in a day that is essentially twice as long as its orbital period.