These panels illustrate how a giant impact could have depleted Mercury’s silicate crust and mantle (blue) while leaving behind an oversize iron core (red). Left: An object half Mercury’s present mass collides obliquely with a 2.25-Mercury-mass protoplanet. This view shows the model 2 minutes after the impact. Center: Within 8 minutes of the collision, both worlds are shattered. Right: This wider view shows the scene 3 hours later. Much of the rocky material has been removed and little of it will return.