ocr: COMET According to present knowledge comets are leftover material from the tormation of the solar system, which were blown to the system's outer edge by solar wind. There this leftover material condensed in the bigger bodies (clouds'). Most of them drifted to paths that took them out of the solar system. Still, at least a billion comets are there still in a very susceptible gravitational state. Even the slightest influence from an external gravitational field will cause some of the comets to start moving and later to become visible comets with shorter periods. During its infancy, the Earth was ...
