A Relentless Blitz Of Small Rocks Obliterated Earth's Early Atmosphere

The Earth went through some tough times after its formation 4.5 billion years ago. Geochemical evidence indicates that its atmosphere was obliterated at least twice. One theory is that a large object from space smashed into our planet's surface, but a new study suggests it was actually thousands of small impacts. » 12/02/14 1:20pm 12/02/14 1:20pm