Early in Earth’s history, space rocks frequently hit the young planet. It is estimated that “giant impactors,” greater than 6.2 miles (10 kilometers) across, pummeled the planet at least ...

It's a low-energy environment without strong currents. Then all of a sudden, you have a giant tsunami, sweeping by and ripping up the sea floor," said Drabon. The S2 meteorite, estimated to have ...