What is the primary driver distinguishing cosmic accretion from terrestrial forms of accumulation?

Answer

Gravity

In space, accretion processes are fundamentally driven by gravity, an inverse-square law force dominating at vast distances. Terrestrial forms are immediately driven by fluid mechanics (like water flow) or plate movement forces.

What is the primary driver distinguishing cosmic accretion from terrestrial forms of accumulation?
Geologyprocessplanetmassaccretion