It formed about four and a half billion years ago when a Mars-sized object called Theia slammed into the newly formed Earth. Theia’s molten iron core sank ... s habitable zone, the region ...

Researchers are now trying to understand the "innermost inner core" of the Earth by studying how seismic waves travel through ...

Other scientists propose that after the impact all of the oxygen was able to move around in the hot vapor surrounding the Earth and moon, mixing up all the different oxygen isotopes and erasing any ...

There's been some new research about an ancient planet - called Theia - that experts think helped form the Earth we know today. Scientists think that Theia crashed into Earth billions of years ago ...