A meteoroid is a small piece of space debris, often from planetary bodies, moving through the solar system. When a meteoroid is larger than a boulder, it is classified as an asteroid. If a meteoroid survives its fiery entry into Earth's atmosphere and lands on the surface, it is then called a meteorite. The streak of light produced as a meteoroid travels through the atmosphere is known as a meteor.
The dangers posed by meteoroids are significant, especially for astronauts in space. Even a meteoroid as small as a tomato seed has the potential to penetrate a space suit, which poses a serious risk to the safety of astronauts. This highlights the importance of understanding and mitigating the hazards associated with these celestial objects, as emphasized by Mary Roach in her book "Packing for Mars: The Curious Science of Life in the Void."