From the October 2011 issue

How can astronomers predict that meteor showers will return year after year?

Gerri Whitehead, Houston, Texas
By | Published: October 24, 2011 | Last updated on May 18, 2023

Icy debris ejected from comets, or dust from a near-Earth asteroid, spreads out into a “stream” of particles along the body’s orbit. A meteor shower occurs when Earth passes through this material, which generally happens at only one point in its orbit. As Earth passes that point at the same time every year, we can predict meteor shower times with good accuracy.