A bowl-shaped pit [[on ground]] ([[planet]]ary surface). It is usually caused either by a [[meteor]]ite impact, powerful [[explosion]], or by geological activity on the planet. On [[earth (planet)|Earth]], craters are generally the results of [[volcano|volcanic]] [[eruption]]. 

h1. See also
* [[mushroom cloud]]
* [[wasteland]]
* [[valley]]
h1. External links
Wikipedia: "Crater":[https://en.wikipedia.org/wiki/Crater]
クレーター