In December 2010, a team of NASA researchers led by astrobiologist Felisa

Wolfe-Simon made a remarkable announcement: Bacteria living in California’s

Mono Lake can replace the phosphorous in their biomolecules with arsenic

(Wolfe-Simon, Blum, Kulp, Gordon, Hoeft, Pett-Ridge et al., 2010). A

first-of-its-kind discovery, the extraordinary biochemistry of species GFAJ-1

offered “proof” that life could exist in environments without phosphorous; that is,

in environments whose chemistries differ vastly from ours. In other words,

different kinds of life might exist on planets with scant resemblance to Earth.