The Secret of the Blood Falls of Antarctica

From a crack in the Taylor Glacier in the McMurdo Dry Valleys of Antarctica flows a curious blood-red colored water. When it was first discovered by geologist Griffith Taylor in 1911, the color was thought to have come from an algae. The source of the red color was later discovered to be an iron-rich underground saltwater lake that was trapped by the encroaching glacier at least 1.5 million years ago. The temperature of the water is -5 Celsius, but it's so salty that it doesn't freeze.

But the Blood Falls houses another secret, which scientists from Harvard University have started to uncover - it's home to an entire ecosystem of bacteria, trapped for millennia in conditions that are extremely inhospitable to life.