Since its landing in 2012, NASA’s Curiosity rover has been analyzing Martian soils and rocks for evidence that the Red Planet could have supported life in its past. So far, Curiosity has found carbon, hydrogen, oxygen, phosphorus, sulfur, methane, and organic molecules. In addition, Curiosity has found evidence of surface water and groundwater. All these discoveries suggest favorable chemistry and conditions for supporting life, although not evidence of life. Most recently, scientists reported in the journal Geophysical Research Letters (September 2017) the discovery of the element boron, which may have acted as a stabilizer for the molecular precursors of life. See also: Boron; Mars Science Laboratory; Robot rover Curiosity lands on Mars; Prebiotic organic synthesis; Space probe
Ribonucleic acids (RNAs) are essential for all forms of life as we known it. The oxidized forms of boron, called borates, may have been important for stabilizing ribose, the sugar group of RNA, on early Earth. Boron was discovered by Curiosity’s ChemCam (Chemistry and Camera) instrument among calcium sulfate deposits left after the evaporation of water. This discovery indicates that boron had been dissolved in water as borates, where it potentially could have reacted with, and stabilized, ribose to make RNA. See also: Astrobiology; Borate minerals; Laser; Ribonucleic acid (RNA); Spectroscopy
