Scientists shocked by size of Mars’ liquid core

NASA scientists have used data from the seismology sensors on the InSight probe to understand Mars's internal structure. The probe has detected small quakes since 2019, revealing that Mars's crust is thinner than expected, ranging from 24 to 72 kilometers thick. The planet's core is larger than anticipated, with a radius of 1,830 kilometers, indicating a thinner mantle. This thin mantle likely cannot sustain the pressures needed for the mineral bridgmanite to stabilize, which on Earth blankets the core and slows heat loss. The absence of this mineral on Mars would have led to rapid cooling, initially allowing strong convection in the core and a global magnetic field. However, due to rapid cooling, Mars no longer has a global magnetic field today.

What has the InSight probe been detecting on Mars since early 2019?

• Volcanic eruptions

• Small quakes

• Dust storms

• Water flows

How does the thickness of Mars's crust compare to expectations?

• Thinner than expected

• Varies greatly

• Thicker than expected

• Exactly as expected

What is the significance of the size of Mars's core?

• It is smaller than expected

• It is the same size as Earth's core

• It is not metallic

• It is wider than expected

Why is the mineral bridgmanite unlikely to be stable in Mars's mantle?

• The mantle is too thick

• The mantle is too hot

• The mantle is too thin

• The mantle is too cold

What was the initial effect of rapid cooling on Mars's core?

• It created a global magnetic field

• It stopped all convection

• It caused the core to expand

• It increased volcanic activity