Mesosiderites are enigmatic mixtures
of metal and igneous rock. Catastrophic collisions more than
four billion years ago may explain this unexpected mingling
of nickel-iron alloy from the core and rock from the surface
of one or more large asteroids. The coarse Widmanstätten structures
in the metal suggest that it cooled very slowly, probably
because the rock-metal mixture was deeply buried following
melting and mixing.
Mount Padbury is a mixture of dark rock fragments from an
asteroids deep interior and shiny metal droplets with
Widmanstätten patterns from a core. They are surrounded
by basaltic material from the surface.