Where on Earth did the water come from?

Earth's supply of water is incredibly important for its ability to sustain life, but where did that water come from? Was it present when Earth formed or was it delivered later by meteorites or comets from outer space?

Whale cams track swimming efficiency of ocean giants

The relatively squat and gangly humpback whale moves more efficiently through the water than its sleeker, larger cousin, the blue whale, according to new research that used devices attached to the animals to collect information ...

page 1 from 5