THE TROUBLED ORIGINS OFk Earths water

摘要

From 350 kilometres (220 miles) up, the International Space Station passes serenely over the Gulf of Mexico and the United States' Gulf Coast, as the Sun beats down, in a scene captured by NASA astronaut Terry Virts.The Expedition 42 Flight Engineer took this photograph from onboard the space station on 14 December, looking down on 660,000,000,000,000,000 (that's 660 quadrillion) gallons of water within the Gulf.