Prairie fireball was comet fragment burning up in Earth's atmosphere The fireball that lit up the sky across the Prairies on Monday morning was a small piece of a comet that burned up in the atmosphere, researchers at the University of Alberta say. Social Sharing 'Hitting our atmosphere would have been like hitting a brick wall for something travelling at this speed' CBC News · Posted: Feb 25, 2021 1:13 PM MT | Last Updated: February 25 Lea Storry was in her home office in downtown Edmonton on Monday when she saw the flash of light streak across the sky. (Lea Storry/Twitter) The fireball that lit up the sky across the Prairies on Monday morning was a small piece of a comet that burned up in the atmosphere, researchers at the University of Alberta say.