A new discovery concerning Gale Crater mud on Mars increases the likelihood that the planet has developed some form of life in the past. This time, it’s not the composition of the mud, but its dried-out, cracked pattern of neat hexagons that matters.
When mud dries, it typically forms a more squared-off pattern. But when mud dries, re-moistens, and dries again repeatedly, the pattern can shift to board-game-like hexagons.
