Asteroid

A captured ‘planet’ may integrate into a particular orbital distance from its star (Sun). Another planet may already exist at or near this distance. This will ultimately result in a collision. When will depend on the mass and velocities of the two objects. The outcome also has these dependencies.

• The asteroid belt may describe such an occurrence.

   It could be that a shower of bodies arrived together and any with the appropriate (correct) velocity, approach angle etc would be captured into an orbit about the Sun. The appearance is one of 'just right', though anything that is not 'just right' is lost. This explains the Asteroid Belt (potential collision). Water (and sand) were delivered to Earth.

• There is another way of considering a meteor shower. The Earth is orbiting the Sun at 29.786km/s and such a shower falls upon the planet. An alternative view is that Earth passes through a relatively stationary asteroid flow.