Magma ocean and first rocky crust on the Moon
Magma ocean and first rocky crust on the Moon
When the Moon formed into a sphere approximately 1700 kilometres in radius 4.425 billion years ago, its interior heated up considerably due to the energy released when it accreted. The rock melted and an ocean of magma, possibly more than 1000 kilometres deep, formed. Later, light rocks crystallised, which rose to the surface and formed a first crust on the Moon. This crust insulated the Moon from space, and the magma ocean beneath it cooled down slowly. Two hundred million years would pass before the Moon completely solidified.
