Abstract
During its five years of operation, the Sample Analysis at Mars (SAM) Tunable Laser Spectrometer (TLS) on board the Curiosity rover has detected six methane spikes above a low background abundance in Gale crater. The methane spikes are likely the consequence of nearby surface emission. Here we use inverse Lagrangian modeling techniques to identify probable upstream emission regions for these methane spikes at an unprecedented spatial resolution. Inside Gale crater, the northwestern crater floor casts the strongest influence on the detections. Outside Gale crater, the emission region with the strongest influence extends towards the north. The contrasting results from two consecutive methane measurements point to an active emission region to the west and the southwest of the Curiosity rover on the northwestern crater floor. The observed spike magnitude and frequency also favor emission sites on the northwestern crater floor, unless fast methane removal mechanisms that are unknown to date are at work.
Mars Methane Sources in Northwestern Gale Crater Inferred from Back‐Trajectory Modeling
