The discovery of a strange bacteria that can use arsenic as one of its nutrients widens the scope for finding new forms of life on Earth and possibly beyond, NASA scientists said on Thursday. While researchers discovered the unusual bacteria here on Earth, they say it shows that life has possibilities beyond the major elements that have been considered essential. Six major elements have long been considered essential for life - carbon, hydrogen, nitrogen, oxygen, phosphorus and sulphur. At a news conference on Thursday at NASA headquarters in Washington, researchers announced that they had found that a bacteria, discovered in Mono Lake, California, is able to continue to grow after substituting arsenic for phosphorus.