What is Meteor?
[[Image:Leonid meteor shower as seen from space (1997).jpg|thumb|250px|meteors falling to Earth]] A '''meteor''' is what you see when a space rock falls to [[Earth]]. It is often known as a '''shooting star''' or '''falling star''' and can be a bright light in the [[wikt:night|night]] [[sky]], though most are faint. A few survive long enough to hit the ground. That is called a '''meteorite''', and a large one sometimes leaves a hole in the ground called a [[crater]]. A rock that has not yet hit the [[atmosphere]] is called a '''meteoroid'''. Meteoroids may range in size from large pieces of rock to tiny dust particles floating in space that did not form [[planet]]s. When the meteoroids enter Earth's [[atmosphere]] they are usually going faster than the Earth's [[escape velocity]] of 13&nbsp;km/sec or [[Mach number|Mach 40]]. This makes them heat up and usually break apart. When the heat makes them glow, they are known as meteors. Meteors are distinct from [[comet]]s or [[asteroid]]s, but some, especially those associated with [[meteor shower]]s, are dust particles that came out of comets. There are several types of meteorites including: stony, carbonaceous chondrites, and iron-nickel. Stony meteorites are named because they are largely made up of stone-like mineral material. Carbonaceous chondrites have a high carbon content. Iron-nickel meteorites are mostly iron often with significant nickel as well. Meteorites happened often during the [[Late Heavy Bombardment]]. Nowadays they sometimes hurt people and property. The [[2013 Russian meteor event]] did the most damage. Large meteorite strikes may have played a part in several of the mass [[extinction]]s, and so indirectly on the course of [[evolution]]. (see [[K/T extinction event]]; [[List of extinction events]]; [[Chicxulub crater]]) == Meteorite types == === Chondrites === [[File:NWA869Meteorite.jpg|thumb|right|A specimen of the NWA 869 chondrite (type L4-6), showing chondrules and metal flakes]] Chondrites are stony (non-metallic) [[meteorite]]s that a