Glass in Alga Crater (IMAGE) Brown University Caption Deposits of impact glass have been preserved in Martian craters, including Alga Crater, shown here. Detection of the impact glass by researchers at Brown University, Providence, R.I., is based on data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on NASA's Mars Reconnaissance Orbiter. In color coding based on analysis of CRISM spectra, green indicates the presence of glass. (Blues are pyroxene; reds are olivine.) Impact glass forms in the heat of a violent impact that excavates a crater. Impact glass found on Earth can preserve evidence about past life. A deposit of impact glass on Mars could be a good place to look for signs of past life on that planet. This view shows Alga Crater's central peak, which is about 3 miles (5 kilometers) wide within the 12-mile (19-kilometer) diameter of this southern-hemisphere crater. The information from CRISM is shown over a terrain model and image based on observations by the High Resolution Imaging Science Experiment (HiRISE) camera. The vertical dimension is exaggerated by a factor of two. Credit Courtesy of NASA/JPL-Caltech/JHUAPL/University of Arizona Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.