Kráteres

Kráteres are circular depressions on the surfaces of planets, moons, and other rocky bodies, formed by a variety of geological processes. The term covers both impact craters, created by high-velocity collisions of meteoroids, and volcanic craters, formed by venting, eruption, or collapse around magma chambers.

Impact craters and volcanic craters are the two main categories. Impact craters begin with an energetic collision that excavates material and ejects it into surrounding terrain. In larger craters, the rebound of the surface after the impact can produce a central peak or a ringed structure, and the outer rim may be terraced. Volcanic craters form at volcanic vents or calderas and are often circular but can be shallower and irregular; some are filled with lava, lava lakes, or volcanic ash.

Morphology varies with size and gravity. Small, simple craters usually have bowl-shaped floors and smooth rims, while larger, complex craters exhibit terraced walls, central peaks, and more irregular floors. Ejecta blankets, bright ray systems, and secondary craters may accompany fresh impacts, helping scientists identify their relative ages.

Kráteres are central to planetary geology. Counting craters on a surface provides clues about its age and resurfacing history, while the preservation of craters is influenced by erosion, tectonics, and volcanic activity. On Earth, many cráter features are eroded or buried, but on the Moon, Mars, and outer solar system bodies they remain key records of early solar-system processes. Notable examples include Meteor Crater in Arizona, the Chicxulub crater, and various prominent lunar craters such as Tycho and Copernicus.