As the ages passed, the pressure of layers above and heat from inside the earthbroke down and reassembled these simple plants and animals into chains of carbon atoms bristling with hydrogen.
It weighed about 10 tonnes when it entered the Earth's atmosphere and broke apart 30-50km (20-30 miles) above ground, according to Russia's Academy of Sciences, releasing several kilotons of energy - the equivalent of a small atomic weapon.
In August 2011, Speth and his chief engineer finally broke through more than two meters of earth and reinforced concrete and the shelter's 278-millimeter-thick ceiling to emerge into a 40-square-meter space, divided into five interconnecting rooms by heavy metals doors.
We may disagree about the best way to reform our health care system, but surely we can agree that no one ought to go broke when they get sick in the richest nation on Earth.
The material that is burning up in Earth's atmosphere during the Quadrantids likely comes from a comet that broke into fragments centuries ago, NASA says.