Why does Mars no longer have a magnetic field?
A)Giant impacts slowed the planet's rotation.
B)Its core cooled and the dynamo effect shut off.
C)Mars does not have a dense core.
D)The thin atmosphere can't protect the planet from the solar wind.

Question

Quizplus · Accepted Answer

Mars no longer has a magnetic field because its core cooled and the dynamo effect shut off. The dynamo effect is the process by which a spinning, molten metallic core generates a magnetic field. As the core of Mars cooled, the dynamo effect ceased and the magnetic field faded away.

Why Does Mars No Longer Have a Magnetic Field