Despite decades of research and exploration, the Arctic and the Antarctica are still a constant source of surprise for scientists. Earlier this year, they discovered a thriving microscopic garden under the ice in the Arctic and now, a robust community of ancient bacteria estimated to be about 2,800 years old.

The amazing discovery, nearly 65 feet beneath the frozen surface of Antarctica's largest lake - Vida, is the result of a seven-year collaboration between scientists from NASA, Reno's Desert Research Institute (DRI), Chicago's University of Illinois and nine other Institutions.

The find is a huge surprise for many reasons. Not only is the temperature a chilling -10°C, but also, the water is extremely salty - about six to seven times more than normal seawater.

Also, there is no oxygen. Instead scientists found what they believe is the largest concentration of nitrous oxide in a natural water environment. Also known as 'laughing gas', because of the effect it has on humans if inhaled in excess, it is a colorless, non-flammable gas. Used by surgeons and dentists because of it is a good anesthetic and analgesic, it is not harmful to humans, but it does react with the Earth's ozone layer and is considered to be a major greenhouse gas.

Since the scientists already know from previous exploration of the area that the microbes have had no help from the outside world for at least 3,000 years, they were able to conclude that they had somehow managed to adapt and thrive in what we had always believed was an environment too hostile to sustain life.

The researchers think that this ancient colony of bacteria has learnt to survive by extracting chemical energy from the hydrogen, nitrate nitrite and nitrous oxide, all resulting from a chemical reaction between the saline in the water and the iron-rich rocks that lie beneath.

According to Alison Murray the molecular microbial ecologist and polar researcher at DRI, and the lead writer of the study that was published on November 26th, this discovery not only gives us insights into how life may have formed on Earth, but also, restores hope that alien life may exist in other similar hostile environments like the subsurface aquifers on Mars.

Resources: NASA.gov, wikipedia.org