Eighth century carbon spike not from comet impact
![comet impact with earth illustration](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2014/01/impact_cropped_free.jpg?fit=860%2C460&ssl=1)
A large comet impact, as this artist's impression shows, could not have caused the carbon-14 spike that occurred around A.D. 775.
Don Davis/NASA
A large comet impact, as this artist's impression shows, could not have caused the carbon-14 spike that occurred around A.D. 775.
Don Davis/NASA