About 13,000 years ago, Earth suddenly cooled during a period called the Younger Dryas. Scientists have long debated what caused this abrupt chill. New research suggests a large comet exploded in the sky above North America. This was not a simple impact but a huge airburst, much like the Tunguska event in 1908 but bigger. The explosion released massive heat and pressure, sparking widespread fires and sudden climate change. Researchers studied soil layers from Arizona, New Mexico, and California. They found a thin black layer linked to the start of Younger Dryas. Inside, they discovered tiny metal pieces, melted glass, and shocked quartz, a special type only made by intense pressure. These clues point to one violent event with effects seen across a vast area. There is no crater because the comet exploded in the atmosphere rather than hitting the ground. Computer models confirm such an airburst can scatter debris widely and cool the planet by blocking sunlight with dust. After this event, many large animals like mammoths vanished, and the Clovis people known for their stone tools disappeared. Fires wiped out forests and food sources, making survival tough. While hunting and disease may have played roles, this comet blast offers a missing piece to Earth's history. The silent evidence hidden in ancient soils shows the sky might have played a dramatic part in changing life on Earth forever.