In the ancient basin of Jezero Crater, NASA's Perseverance rover has found something Mars was not supposed to hold — corundum, the crystalline mineral that gives Earth its rubies and sapphires. Detected in three separate rocks through laser-induced luminescence, the discovery confounds established geochemistry, since corundum and the plagioclase minerals surrounding it should not coexist. Scientists now look to the crater's own violent birth — a primordial impact of enormous force — as the forge that made the impossible possible, and in doing so, they find a renewed argument for bringing a pie