World’s deepest zoo harbors clues to extraterrestrial life

Maggie Lau works in a gold mine. But what she seeks here, more than a kilometer and a half (a mile) below the South African surface, may be more precious than gold. She’s looking for life.

It’s not easy work, lit only by headlamps. At times, it can feel as hot and humid as a sauna. Some spots smell like rotten eggs, due to sulfide gas emanating from holes dug in the rock.

Until about 20 years ago, scientists weren’t even sure if life existed deep below Earth’s surface. Then in 1992, Tullis Onstott and his colleagues discovered bacteria growi ... Read more »