Magnetization of sinking porous diapirs in planetesimal cores

Magnetization by core dynamo activity in large asteroids and planetesimals is suggested the remnant magnetization of many achondritic meteorites. However, conditions for a sustained such small bodies problematic several reasons. Such may not have energy budget or size to achieve sufficient dynamo. Moreover, given their low internal pressures, planetesimal cores likely freeze from top down, wherein gravitationally unstable solid freezing front has high viscosity easily destabilized. The delaminate intermittent pulses, which can lead ephemeral intervals vigorous convection drive activity, although they be too short lived fully magnetize planetesimal. delaminated diapiric downwellings solidification are partial melts mushes thus porous, two-phase bodies. Percolative flow seepage through diapir potentially induce quickly, possibly allowing rapid triggering activity. We build on our recent magnetohydrodynamic theory examine porous metallic sinking liquid metal presence an imposed background field. Without (i.e., if it were rigid impermeable), magnetic field distorted around diapir, as expected. Some distortion offset with addition diapir. fast establish dipole moment inside points opposite direction descent. Wide-spread delamination diapirism could therefore rapidly multi-polar poloidal whose lines extend outside core, thereby remanent solidifying material above it.