Small amounts of carbonate minerals have been discovered on the surface of Mars for the first time. The result could help researchers better understand the history and evolution of the planet as part of their efforts to determine if the conditions for sustaining life ever existed there. Joshua Bandfield and colleagues at Arizona State University discovered that particles on the surface of Mars reflect and absorb infrared radiation in a way that exactly matches that of magnesium-rich carbonates found on Earth (J Bandfield et al. 2003 Sciencexpress to be published).