Scientists say a series of explosions in the skies over Russia's Ural Mountains region was caused by a meteor. The impact was was most likely an exploding fireball known as a bolide. Bolide is a generic term to describe any extraterrestrial object under 6 miles long that speeds into the Earth's atmosphere at velocities around 40 miles per second — roughly the same speed as a bullet.
Nina Sen is a frequent contributor to Live Science’s Life’s Little Mysteries series: an exploration and explanation of our world’s phenomena, both natural and man-made. She also writes astronomy photo stories for Live Science's sister site Space.com.