It takes 176 earth days. So, the sun appears to move very slowly in Mercury's sky. One rotation with respect to the stars is a siderial day. A solar day is the time that it seems to take the sun to go around the sky once. The siderial day on earth is 23 hr.
Mercury shows some variety of surface features.
Mercury has a weak magnetic field, which was not predicted, as it has a solid core, and rotates slowly.