Secrets of Mercury's Core

Today at the 40th Lunar & Planetary Science Conference in the Woodlands, Texas: We saw new data from the MESSENGER mission to Mercury. No spacecraft has flown by the innermost planet since Mariner 10 in 1974. Surprisingly Mariner discovered that tiny Mercury has a strong magnetic field. On its way to orbit the planet, MESSENGER has already made two flybys that have vastly increased our knowledge of the planet.

Analyzing the data, scientists have found that Mercury's field is concentrated in the core, with virtually no crustal magnetic field. This is not surprinsing, since the surface so far appears devoid of magnetic minerals. How tiny Mercury maintains a magnetic field has been a mystery for 38 years. If Mercury's core had formed around a tiny singularity, the planet's centre would be a hot cavity of charged plasma. This would generate heat that would reach the surface as vulcanism. If the Black Hole rotated, spinning plasma would create a magnetic field concentrated at the core. Mercury's centre would be an excellent place to find a Black Hole.