Mercury’s Iron Heart: How Simulations Reveal the Origins of the Solar System’s Most Metal-Rich Planet
Haniyeh Tajer and colleagues used N-body simulations to explore why Mercury’s iron core is so large. They found that giant impacts alone cannot explain its composition. Instead, an iron-rich inner disk in the early solar system best reproduces Mercury-like planets, while outer regions yield Earth-like worlds. This suggests chemical gradients, not catastrophic collisions, shaped both Mercury and similar dense exoplanets.
When Impacts Supercharged Mercury’s Ancient Magnetic Field
Isaac Narrett and colleagues show that giant impacts on Mercury, like the Caloris Basin event, could have briefly amplified the planet’s weak magnetic field by up to 20 times through hot plasma generation. These amplified fields may have been recorded in rocks at the impact’s antipode, explaining parts of Mercury’s ancient magnetization, though a stronger ancient dynamo is still needed to account for all observations.