by Katie Bowell, Curator of Cultural Interpretation
At a conference today, NASA announced that the first known life form to use arsenic to make its DNA and proteins: the bacteria GFAJ-1.
This new life form is a surprise. Out of all the elements on Earth (watch Daniel Radcliffe if you need to remember what they all are), life is mainly composed of carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus. Other elements just don’t go and insert themselves into that group. Or, at least, they didn’t. GFAJ-1 is able to substitute arsenic for phosphorus, the only known living organism to be able to do this.
Many people are also talking about possible implications from the discovery for astrobiology. If life can grow on Earth outside of the parameters we expect, what extraterrestrial environments could be home to life?
For a summary and analysis of the discovery, read on here.