Earth held a deep ocean of magma beneath its surface in its early history, new research finds, potentially explaining odd anomalies seen in the mantle today.
This basal magma ocean has been hotly debated for years. Some geochemical evidence indicates that in the first few hundred million years of the planet's existence, a persistent sea of melt formed at the boundary between Earth's core and its middle layer, the mantle. But models of the planet's formation suggested that when Earth was new and molten, it solidified from the bottom up, making it hard to understand how a deep magma ocean could exist.
