Asteroid Dust: The Deadly Winter that Wiped Out Dinosaurs

A new study suggests that fine silicate dust from the Chicxulub asteroid, which remained in the atmosphere for up to 15 years, played a more significant role in causing the impact winter and mass extinction event that killed the dinosaurs than previously thought. The dust particles, found at the Tanis fossil site in North Dakota, were the right size to stick around in the atmosphere and dropped global temperatures by up to 15 degrees Celsius. Climate models indicate that the dust likely caused a "catastrophic collapse" of life by shutting down photosynthesis in plants for at least a year.