Magma oceans exist during periods of Earth's or any planet's accretion when the planet is completely or partly molten.[1] In the early solar system, energy to melt objects came largely from the decay of radioactive aluminum-26.[2] As planets grew larger, the energy was supplied from large or giant impacts.[3] During its formation, the Earth likely suffered a series of magma oceans resulting from giant impacts,[4] the final one being the Moon-forming impact.