NASA said it has found microbes that can use arsenic as one of the building blocks of life sustaining DNA.The concept of NASA discussing alien life has sparked interest across the world.
NASA's announcement on Thursday afternoon has shown that alien life might have been under scientists' noses all along. Two years of study at Mono Lake near Yosemite National Park in California have yielded a type of bacteria that thrives on the toxic chemical arsenic.
Scientists at the National Aeronautics and Space Administration said they found microbes in the mud beneath a California lake that can use arsenic -- usually considered toxic -- rather than phosphorus as one of the building blocks of its DNA. Phosphorus is one of the elements that sustains all other life forms on earth.
The finding is important because the bacterium uses arsenic in place of phosphorus - an element previously considered vital for all forms of life.
If there can be life without phosphorus then there are thousands more planets which could sustain life of some sort.
Astrobiology is the study of the origin, evolution, distribution and future of life in the universe, and NASA is widely expected to announce that the discovery of arsenic-based life on Earth, a find that could change its future quest for life on other planets.
"We know that some microbes can breathe arsenic, but what we've found is a microbe doing something new – building parts of itself out of arsenic," said Felissa Wolfe-Simon, a NASA astrobiology research fellow and lead scientist on the study. "If something here on Earth can do something so unexpected, what else can life do that we haven't seen yet?"
The newfound microbe, called GFAJ-1, was cultivated in an environment with scarce amounts of phosphorus and generous helpings of arsenic. Even when phosphorus was taken out of the mix in favor of more arsenic, the being continued to thrive, which debunked the idea that arsenic was a hostile chemical. In fact, it helped GFAJ-1 grow.
"The idea of alternative biochemistries for life is common in science fiction," said Carl Pilcher, director of NASA's Astrobiology Institute at the Ames Research Center in California. "Until now a life form using arsenic as a building block was only theoretical, but now we know such life exists in Mono Lake."