Lake Vida, a salty lake buried under a 60-foot-thick sheet of ice in Antarctica, has renewed scientists' hopes of finding alien life in space, even in the most inhospitable places. The lake, which has been completely sealed off from the rest of the world for thousands of years, is surprisingly teeming with microbial life. "By seeing what the boundaries of life are on Earth, that helps us when we go out and look for examples elsewhere," says Peter T Doran, a professor at the University of Illinois’ Earth and Environmental Science department. Here, a guide to this mysterious lake: 

Where exactly is Lake Vida? 
Victoria Valley in Antarctica. The lake is covered year-round by the thickest non-glacial ice on Earth, measuring at least 60 feet deep. This layer of ice has isolated the lake from the surface for 2,800 years, and as a result, the water contains no oxygen or light. It is seven times saltier than average sea water, which keeps the lake water from freezing completely despite its extremely cold temperature of roughly 8 degrees Fahrenheit.

But scientists discovered life there? 
They sure did. After taking samples from the core of the ice, researchers were surprised to find previously unknown species of bacteria. The lake contains about one-tenth the amount of microbial life found in freshwater lakes.

How could this bacteria possibly survive in this lake?
Researchers aren't completely sure, but they suspect a chemical reaction between the salt water and the rocks below is producing hydrogen, which could serve as a fuel source. Whatever the answer, "the fact that things are alive in Lake Vida at all further extends the idea that where there is water, there is life," says Colin Schultz at Smithsonian 

What does this have to do with alien life? 
If life can survive in Lake Vida's harsh conditions, imagine what that means in the hunt for life elsewhere in our solar system. "This provides us with new boundary conditions on the limits for life," says Doran.

Sources: Wired, Smithsonian, CBS News, Los Angeles Times