Micrometeorites are tiny particles from space that enter Earth's atmosphere. They are typically less than 1 millimeter in size and can originate from comets, asteroids, or even the Moon and Mars. As they travel through the atmosphere, they can heat up and sometimes melt, creating small, solid remnants that land on Earth. These tiny space rocks are important for scientific research because they provide insights into the composition of our solar system. By studying micrometeorites, scientists can learn more about the materials that formed planets and other celestial bodies, contributing to our understanding of planetary formation and cosmic history.