How Does Mercury Rotate, Relative to the Sun

question 154

Multiple Choice

How does Mercury rotate, relative to the Sun?

• A) Mercury rotates relatively quickly, so that a solar day (from sunrise to the next sunrise) on Mercury is just a bit shorter than on Earth.
• B) Mercury rotates in a retrograde direction; consequently, the Sun rises in the west each day and sets in the east.
• C) Mercury turns the same side (Caloris Basin) toward the Sun at all times, much as the Moon turns the same side toward Earth.
• D) Mercury alternately turns one side (Caloris Basin) toward the Sun at one perihelion and the opposite side toward the Sun at the next perihelion.