75% of asteroid hunter's discoveries are called C type asteroids. They are dark, have a high abundance of carbon, consist of clay and silicate rocks, and may have a composition which is up to 22% water. Recently Dr. Phillip A. Bland of Curtin University in Australia and Dr. Bryan Travis of the Planetary Science Institute in Tucson, Arizona published an article in the on line journal Science Advances describing their numerical simulations of the evolution of the progenitors of the C type asteroids. These researchers find that these common asteroids are likely to have started out as giant convecting mud balls which could still exist at the center of large asteroids like Ceres. The C type asteroids are particularly significant in that they are likely to have been one of the ingredients which came together under gravity to form Mercury, Venus, Earth, and Mars. Their impacts upon a young Earth are likely to be the source of the water in our oceans. Of more immediate interest is that the type C asteroids could be a handy source of water and raw materials for space colonists either as they are currently flying through space or found buried in impact craters on the Moon.