Sixty-six million years ago an asteroid as large as Mt. Everest hit what is now the Yucatan Peninsula at a speed ten times faster than the fastest rifle bullet. Debris from the impact blew into space, re-entered the atmosphere as a swarm of shooting stars that burned the global forests and grasslands, leaving behind a thin global layer containing rock from the asteroid and from Mexico, and smoke from the fires. This layer marks one of the greatest extinctions in Earth history including not...

Sixty-six million years ago an asteroid as large as Mt. Everest hit what is now the Yucatan Peninsula at a speed ten times faster than the fastest rifle bullet. Debris from the impact blew into space, re-entered the atmosphere as a swarm of shooting stars that burned the global forests and grasslands, leaving behind a thin global layer containing rock from the asteroid and from Mexico, and smoke from the fires. This layer marks one of the greatest extinctions in Earth history including not...