From ancient life to alien life: Living where the sun don't shine

MODERN life is powered by the sun. But photosynthesis, the process that converts sunlight, carbon dioxide and water into plants, is a mere 2.4 billion years old. Life itself goes back at least 3.5 billion years. Before photosynthesis, the energy must have come from something else. Without understanding what that something was, it is impossible to know how life on Earth got going. Moreover, there are those who think that whatever did power Earth-bound life before photosynthesis might also power it on other planets. Which is why, on October 7th, a mission was launched from Cape Canaveral—not from the rocket pads in the north of the cape, but from the docks at its south.

The good ship Cape Hatteras, crewed by Chris German of the Woods Hole Oceanographic Institution (WHOI), in Massachusetts, and his colleagues, will act as a base for the exploration of a region of inner, rather than outer space—specifically, the Mid-Cayman Rise, a submarine mountain range that lies under almost 7km (about 4 miles) of water near Grand Cayman island in the Caribbean. When it gets there, Cape Hatteras will launch Nereus, an unmanned submarine, named after an ancient Greek sea god, that is capable of withstanding the pressure at such depth (it went down 11km on a previous expedition).

The Caribbean may seem an unlikely place to study extraterrestrial life, but this is no junket. The reason for going there is that the Mid-Cayman Rise is part of the 60,000km-long system of mid-ocean ridges that zigzags around the planet like a network of giant zip fasteners which open up regularly to reveal the liquid rock beneath. Moreover, it is a particularly unusual part of that network—one which some believe may also reveal what the earliest life on Earth looked like and thus give hints about how life might develop elsewhere. ...

via From ancient life to alien life: Living where the sun don't shine | The Economist.