Scientists from US space agency NASA will today announce they have discovered an organism that is alien to every other known lifeform.
NASA scientist Felisa Wolfe Simon will reveal the completely new type of life at a press conference at 14:00 EST Thursday, according to a report on tech gossip site Gizmodo.
Those of you who can remember back to their school days (our recollections are hazy) may recall being told that all life consists of a cocktail of the elements carbon, hydrogen, oxygen, nitrogen, phosphorus and sulphur.
And so it had been thought - that every living thing on earth is based on the same recipe that bubbled out of Earth's primaeval soup billions of years ago. That the DNA of every lifeform, from bacterium to blue whale, was based on the same six building blocks.
Every living thing, that is, except one.
NASA scientists have found, floating about in California's poisonous Mono Lake, a type of bacteria that uses arsenic instead of phosphorus - something previously thought impossible.
The discovery opens the way for the possibility of organisms existing in places previously thought ot be incapable of supporting life.
No further details about the bacteria are available as yet. We'll be tuning in for a close encounter at the space agency's website at 19:00 GMT .