New models reveal the K-Pg impact's killing mechanism: months of darkness, not the blast

Sixty-six million years ago, a single morning's violence set in motion a years-long darkness that unmade three-quarters of life on Earth — not through the force of impact alone, but through the slow suffocation of sunlight. The Chicxulub asteroid, striking the Yucatán Peninsula with energy equivalent to five billion nuclear detonations, lofted a shroud of dust, soot, and aerosols that collapsed the photosynthetic foundations of nearly every ecosystem on the planet. Scientists continue to refine which ingredients composed that darkness and how long it endured, but the deeper truth is already le