Glassy Deposits Detected On Mars

Scientists have detected glassy soil deposits on Mars that likely formed during ancient meteorite impacts (Geology 2015, DOI: 10.1130/g36953.1). Organic molecules and other biologically produced substances have been found suspended in similar glass deposits on Earth, suggesting that the discovery provides a new target for investigating possible past life on Mars. Kevin M. Cannon and John F. Mustard of Brown University found evidence for the martian glass in visible-infrared spectra taken by a spectrometer on NASA’s Mars Reconnaissance Orbiter. Because spectra from glasses are weak, definitive identification would typically be difficult. But the researchers produced glasses in the lab under simulated martian conditions and were able to use spectra from those samples to provide a reference for the observed glass spectra. The spacecraft detected the glass deposits in jagged peaks of soil in the center of impact craters, suggesting that the glass was generated during the hot explosions of bombarding meteorites. One glass-containing crater, called Hargraves, is near a region rich in crust that formed during Mars’s watery past. Scientists are considering that area as a possible landing site for a future Mars rover mission.