From Belinda Smith at Cosmos:
A Mercury-sized planetary embryo that slammed into Earth around 4.4 billion years ago delivered virtually all of the planet’s carbon, new research suggests.
Unravelling the early Earth’s composition is no easy feat. Billions of years ago, the solar system was a whirling mess of comets, asteroids and proto planets.
One scenario that could yield today’s volatile concentrations was if a carbon-rich Mercury-sized planet with a core full of silicon or sulfur smashed into and was absorbed by Earth.
The dynamics of the collision meant the silicon sank straight to Earth’s core while the carbon was mixed with the mantle, ready to be cycled up to the crust and eventually, develop life. More.
Two planets did suffer a violent collision, we are told, nearly a decade ago.
See also: Our Moon formed in collision with embryo planet?
What we know and don’t know about the origin of life
Follow UD News at Twitter!