Impactite is an informal term describing a rock created or modified by the impact of a meteorite. The term encompasses shock-metamorphosed target rocks, melts (suevites) and mixtures of the two, as well as sedimentary rocks with significant impact-derived components (shocked mineral grains, tektites, anomalous geochemical signatures, etc.). In June 2015, NASA reported that impact glass has been detected on the planet Mars - such material may contain preserved signs of ancient life—if life existed.
When a meteor strikes a planet's surface, the energy release from the impact can melt rock and soil into a liquid. If the liquid cools and hardens quickly into a solid, impact glass forms before the atoms have time to arrange into a crystal lattice. Impact glass is dark brown, almost black, and partly transparent.