Fossilized space dust from 2.7 billion years ago holds surprise about Earth's ancient atmosphere

Each year, more than 3,000 tons of space dust fails to burn up in our planet's atmosphere and falls instead to Earth's surface.

These micrometeorites are just a few microns in diameter, but scientists say that embedded in the fossilized specks of this extraterrestrial debris are chemical clues...

via L.A. Times - Science http://ift.tt/1rGszor