WASHINGTON, April 25, 2012 /PRNewswire-USNewswire/ -- Research by NASA and international scientists concludes giant asteroids, similar or larger than the one believed to have killed the dinosaurs,

Bombardments of 'micro-meteorites' on Earth and Mars 4 billion years ago may have caused the planets' climates to cool dramatically.

The study shows that the comets were probably captured 600 million years after the formation of the solar system, during the Late Heavy Bombardment

British scientists say large bombardments of meteorites four billion years ago might have made early Earth and Mars more habitable for life. Imperial College London researchers said millions of meteor strikes during what's called the Late Heavy Bombardment approximately 3.9 billion years pelted Earth

Large bombardments of meteorites approximately four billion years ago could have helped to make the early Earth and Mars more habitable for life by modifying their atmospheres.