The Sample Analysis at Mars (SAM) tunable laser spectrometer onboard Curiosity last week detected surprisingly high levels of the gas methane at Gale Crater: about 21 parts per billion units by volume (ppbv), the largest amount of methane the rover has ever found. Mosaic of the Valles Marineris hemisphere of Mars projected into point perspective, a view similar to that which one would see from a spacecraft. The distance is 1,550 miles (2,500 km) from...
