The world awoke this Christmas morning to the dramatic news that the answer to one of the great questions of all time had been found – we are not alone in the universe!

But the discovery of life on a distant planet with the unprepossessing name of OGLE-2005-BLG-390Lb is hardly the stuff of science fiction. Far from green-skinned, one-eyed, tentacled monsters, the life discovered by a joint Chinese-Korean expedition is a form of lowly bacteria.

Nevertheless, Lord Rees, President of the Royal Society and Astronomer Royal, described the find as one of mankind’s greatest scientific achievements.

We have long been fascinated by the bizarre behavior of bacteria, some of which have been found living in deep sea vents at temperatures around 600 degrees F – supposedly “impossible” to support life. Others have been brought back to life after being entombed in rock for 300 million years.

But the search for life – on earth and in space – changed with a discovery back in the dying days of 2010. NASA scientists found a bizarre life-form at the bottom of Mono Lake in California, an arsenic-rich, super-salty, alkaline body of water toxic to most organisms.

The bacteria they discovered there and developed in the lab forced a change in the very definition of life, after the astonished scientists observed that it ate and grew on arsenic.

“In this bacteria, arsenic replaces phosphorous, until now considered one of the six elements essential for life,” said Warren Berry, NASA spokesman. “The result has been to dramatically broaden the search for life. Quite simply, we have always looked for life as we knew it – but this is life as we did not know it.”

Kwong-Hang Ling, leader of the joint Chinese-Korean expedition, said the find was a turning point in the history of mankind. “If this form of life is possible, then there is no reason why advanced forms could not also have developed, beyond what we used to consider life to be,” he said.

It’s life, but not as we know it.