Wednesday, March 28, 2012

Terms from nasa.gov

KEY TERMS
Plate tectonics: The movement of rigid plates (lithosphere) on a mobile upper mantle (asthenosphere).
Erosion: The movement or grinding away of surface materials by wind, water, ice, or gravity.
Dendritic drainage patterns: Networks of stream channels caused by flowing waters.
Permafrost: Frozen layer at variable depth below the surface in frigid regions of a planet.
Impact Craters: Craters formed when objects or impactors smashed into the surface.
Ejecta: Material thrown out of the area that becomes the crater during impact; does not account for all material since much is vaporized or melted.
Rays: Bright streaks starting from a crater and extending away for great distances.
Raised Rim: Rock thrown out of the crater and deposited in a ring-shaped pile at the crater's edge during an impact.
Crater Floor: Bowl-shaped or flat area of a crater, usually below the surrounding ground level unless filled in with lava.

No comments:

Post a Comment