Scientists wonder about the concentrations of methane gas, which can have geologic and biotic origins, that was detected in the Martian atmosphere by NASA's Curiosity rover. Traces went beyond what they expect to see. "If the methane detections are confirmed, and we do not find any signs of bacterial life, this means there are likely some interesting geological processes happening on Mars that we don't yet know about," said astrobiologist Dirk Schulze-Makuch of Washington State University in Pullman.