Most asteroids orbit in the space between Mars
and are believed to be fragments of bodies that could not become large planets. Because asteroids represent frozen fossil
records in the early stage of evolution from dusts to planets
, studying their composition, distribution, and surface morphology give us precious information on the environment of the solar system in the region each asteroid formed. Together with meteorites
, most of which came from asteroids, observation and exploration of asteroids lets humanity to look into the past of our solar system
. Some asteroids come very close to the Earth
, giving a threat to life on Earth. However, the same fact is also a blessing to humanity because we have an opportunity to capture such Earth-approaching asteroids to make them precious resources for metals, rocks, soils, organics, and water to construct spaceships and space colonies. In the past, when there was no human beings, all asteroid impacts on the Earth, even those which caused mass extinction of life, were a part of destiny as a part of God's Plan of creation. However, once we develop an ability to control such impactors to the Earth, it will be our responsibility whether to let them happen or avoid them.