 In 2011, planetary scientists Erik Asphaug and Martin Jutzi proposed a model in which a second moon would have existed 4.5 billion years ago, and later impacted the Moon, as a part of the accretion process in the formation of the Moon.In 2018, it was confirmed two dust clouds orbited Earth at the Moon's , known as the Kordylewski clouds.These were nicknamed "Earth's hidden moons".