Is Earth actually two planets? by KRISTEN BOBST
A new spin on the giant impact hypothesis says yes. Scientists at UCLA have discovered that Earth is made up of two planets: Earth and Theia. Theia, a Mars-sized protoplanet, crashed into Earth 4.5 billion years ago when Earth was just 100 million years old. Previously, the giant impact hypothesis suggested that Theia sideswiped Earth,… Read more »