Criticism of the melted Moon theory

Kuiper [1954] has proposed that the moon accumulated at low temperature and was heated to the melting point by the decay of radioactive elements, until the interior melted, leaving a sintered ‘accreted crust’ on the outside. At this stage massive objects collided with the moon and broke through the crust, and lava from the interior flowed up into the holes thus formed. On solidification, these pools of lava formed the maria and the flooded craters (referred to as the ‘wet craters’). Later the moon solidified, and subsequent collisions produced the ‘dry craters,‘ i.e., those not having flooded interiors.