That's probably because of the light refracting off the particles. Sometimes, if the explosion is large enough you may hear it. Meteors have been seen traveling across the sky and even bouncing back out into space. The particle usually is a piece of interstellar dust, called a meteoroid. On clear nights, especially away from lights and away from clouds, meteors can be seen flying through sky.
Observations increase as meteors become concentrated in showers that can reach over ten per minute.
When there are more than one or more per second you have a storm. That's 20 per second. What a sight that must have been. In early to mid June two meteor showers, the Arietids and Zeta Persieds come. These contain thousands of meteors.