Gradual removal of the successive surface layers of a material through various processes.

  1. The gradual removal and loss of meteoritic material by heating and vaporization as the meteoroid experiences frictional melting during its passage through the atmosphere. The resulting plasma ablates the meteor and, in cases where a meteor achieves stable flight, the meteorite may develop regmaglypts, roll-over lipping, and other features associated with oriented flight. The particles released during ablation will ionize the surrounding atmospheric molecules, which later de-excite to produce the glowing trails commonly associated with this type of object.
  2. Terrestrial ablation processes include reduction of a glacier by surface melting/sublimation and rock weathering by hydraulic or aeolian (wind) erosion. Ventifacts are beautiful examples of rocks ablated by sand and wind creating aerodynamic shapes reminiscent of some oriented meteorites.