Asteroids are essentially remnants of the primitive building blocks that created the terrestrial planets in our solar system. Scientists believe that asteroids have not changed very much since the time they were formed, making them cosmic time capsules that can reveal how planets like our own world formed.
In addition, asteroids are thought to contain organic molecules like amino acids—the basis for proteins and DNA—leading to speculation that a meteorite from an asteroid could have seeded the early Earth with the building blocks of life.
Despite what Hollywood movies may lead us to believe, the risk of a collision between an asteroid and Earth is extremely small. NASA’s Center for Near-Earth Object Studies regularly monitors the orbits of near-Earth asteroids and calculates their risk of impact within the next 100 years.