NASA's Asteroid Impact Map Shows that Earth Is Hit By Fireballs 'All the Time'
The new asteroid impact map released by NASA shows that, in the last twenty years, Earth has been hit by small asteroids- also called bolides or "fireballs"- 556 times, or with a frequency of approximately every other week. In NASA's words, "It happens all the time."
This map, which shows nighttime incidents in blue and daytime incidents in yellow, is not necessarily a comprehensive map of asteroid impacts, but a map of the impacts that were detected through infrasound technologies.
The good news is that, since these events happen "all the time," asteroid impacts are not generally catastrophic, as most of these "fireballs" are less than a meter wide. "We now know that Earth's atmosphere does a great job of protecting Earth from small asteroids", said NASA NEO Observations Program Executive Lindley Johnson. However, the data from this study will be used to better gauge the probability of larger, more devastating impacts in populated areas. "How big is the population of larger asteroids we really need to worry about? We need to better understand that."
According to NASA, an asteroid the size of a football field hits Earth once every 5,000 years, which causes "significant damage," while a massive asteroid that can cause global disaster hits Earth every few million years. Donald Yeomans, manager of NASA's NEO Program Office at the Jet Propulsion Laboratory, said, "The aim is to find potentially hazardous asteroids before they find us."