What surprised scientists to learn about Mercury from MESSENGER's data?
A) Mercury is still geologically active with molten lava flows on the surface.
B) Mercury does have an atmosphere causing some erosion of the surface.
C) Mercury has significantly more craters than the Moon.
D) Mercury has a magnetic field despite its size.
E) Mercury is rotating faster than earlier predicted.

Question

Quizplus · Accepted Answer

Mercury having a magnetic field was surprising because its small size and slow rotation rate made scientists skeptical about the presence of a molten, dynamic outer core necessary for generating a magnetic field, as observed by MESSENGER.

What Surprised Scientists to Learn About Mercury from MESSENGER's Data