How the dinosaurs died is maybe the most well-known story in all paleontology, but the dinosaurs' origins are more obscure. Dinosaurs might well have gotten their chance to rule the planet from the very thing that later killed them off.
For years, radiometric dating of lunar rock samples has suggested that the formation of the Moon occurred roughly 4.57 billion years ago — around the same time as the birth of the solar system itself.
The two sides of the Moon look nothing like each other: the near side is flat and low, while the far side is incredibly mountainous. We may now be able to solve this topographical mystery...and it involves a second moon.