www.psrd.hawaii.edu/April07/irons.html

When Worlds Really Did CollideWhen Worlds Really Did Collide

• Iron meteorite cooling rates– Compositional zoning– Size of intergrowths

Intergrowths intaenite “cloudyzone”

Zoning in taenite

www.psrd.hawaii.edu/April07/irons.html

When Worlds Really Did CollideWhen Worlds Really Did Collide

• Cooling rates of group IVA irons (fourth largest group) range over a factor of almost 100

• Implies cooling of a metallic core with little or no rocky insulation

• How do we produce a huge (300 km) blob of molten metal?

www.psrd.hawaii.edu/April07/irons.html

When Worlds Really Did CollideWhen Worlds Really Did Collide

• Collisions of molten planetesimals may be the answer

• Consistent with dynamical models of planetary accretion