Whereas most of the ancient Greeks and European medievals had believed the earth was at the center of the universe - with the sun, moon, planets ... In the early seventeenth century, Copernicus ...

Meteors and other galactic debris shower the planet over its first half-billion years, making it entirely uninhabitable. 4,550 mya: Birth ... early atmosphere Gases released from magma inside ...

Right after Earth was born, it is believed to have been a hostile volcanic hellscape filled with magma. The Hadean period, the first phase of our planet's ... Two early continents are also ...

Its gravity gently tugs on Earth ... every orbit it makes around the planet. The moon may seem calm and quiet – and it is, geologically speaking – but its birth was not so tranquil.