Overview
- The Mastcam panorama was assembled from 340 images taken June 19–20 and released in late July to show a contiguous field of small polygonal fractures across Valle Grande.
- Each polygon measures about 4 to 8 centimeters across and the pattern extends to the rover's horizon, making it the largest polygonal patch Curiosity has observed on its climb of Mount Sharp.
- Mission scientists are now measuring the polygons' geometry and the local chemical makeup to test three leading formation ideas: drying mud cracks, thermal contraction from temperature swings, or compaction of buried sediments.
- Those analyses follow Curiosity's April report that a drilled rock contained 21 carbon-bearing molecules, including a nitrogen heterocycle, findings that show rich organic chemistry but do not prove past life.
- If the polygons record aqueous processes, they could narrow when lakes and streams existed in Gale Crater; the team will combine stratigraphy, morphology and chemistry in coming weeks to refine the crater's wet-history timeline.