Coordination between results from Mars Express and Curiosity pin down the likely location of a 2013 methane release to an area about 500 km east of Gale Crater.

This possibly represents some excellent serendipity in that Curiosity's landing site was chosen for the phenomena inside Gale, not for its proximity to some location upwind of it.

This makes "follow the methane" an intriguing exploration pathway parallel to the other exploration in progress.

If there's a surprise for me here, it's that the ExoMars Trace Gas Orbiter had no role in this work, as it's an analysis of measurements done before TGO even arrived. Presumably, when TGO's dataset is ripe, there'll be a much more elaborate story to tell, even if it's only a matter of non detection.