Nasa scientists are set to announce that bacteria have been discovered that can survive in arsenic, an element previously thought too toxic to support life, it can be revealed.
In a press conference scheduled for tomorrow evening, researchers will unveil the discovery of the incredible microbe - which substitutes arsenic for phosphorus to sustain its growth - in a lake in California.
The remarkable discovery raises the prospect that life could exist on other planets which do not have phosphorus in the atmosphere, which had previously been thought vital for life to begin.
But it will come as a major disappointment for those who had hoped Nasa was about to announce that it had found life on other planets.
Nasa sparked alien hysteria around the world with its announcement of a major press conference to be held tomorrow.
It induced feverish debate as to whether scientists were about to announce that they had discovered life on other worlds.
But after The Sun broke the embargo on the story this morning, it can be revealed that the truth is rather closer to home.
The scientists discovered the bacteria in Mono Lake near California's Yosemite National Park.
The space agency had said it plans to reveal an 'astrobiology finding that will impact the search for evidence of extraterrestrial life' but the information was under embargo until 7pm GMT.
The announcement caused frenzied speculation on the internet.
'Did they find ET?', asked one headline in the U S., while another wrote, 'Has Nasa found little green men?'
Speculation mounted around the world about the mystery information and buoyed people who already believe in aliens.