David McNew/Getty Images

According to reports, NASA has discovered, in Mono Lake, a completely new life form, a bacteria that uses arsenic instead of phosphorus in its DNA.

Researchers have discovered a new form of bacteria that has the ability to use arsenic, an element that is usually toxic for life, as a growth nutrient. The new discovery has sparked a debate about which elements are really needed to create and sustain life and whether or not life on other planets could sustain itself by using other elements. Before the discovery, the six major elements thought essential for life were carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur – now add arsenic. The bacteria was discovered in Mono Lake, California, an obviously terrestrial location but one that is quite alien looking. So what does it take for life to form, and do we Earthlings really know as much about life as we think we do?

Guests:

Ariel D. Anbar, Professor in the School of Earth & Space Exploration and the Department of Chemistry & Biochemistry at Arizona State University; co-author of the report.

Bill Nye, Executive Director of the Planetary Society