http://www.voanews5aitmne6gs2btokcacixclgfl43cv27sirgbauyyjylwpdtqd.onion/a/study-details-differences-between-deep-interiors-of-mars-and-earth/7065541.html
One of the most important ways a core can impact habitability is to generate a planetary dynamo," Irving said. "Earth's core does this but Mars' core does not — though it used to, billions of years ago. Mars' core likely no longer has the energetic, turbulent motion which is needed to generate such a field," Irving added.