Asteroid impact could damage the earth protective layer

A new computer simulation suggests that the water vapor and sea salt thrown up by the impact could damage the protective ozone layer, leading to record levels of ultraviolet radiation that could threaten human civilization. Elisabetta Pierazzo of the Planetary Science Institute in Tucson, Arizona, and colleagues used a global climate model to study how water vapor and sea salt thrown up from an impact will affect ozone levels for years after the event. Some simulated impacts created depletions that were still felt across the whole Earth a year later.