The Devistation of a Large Meteoritic Impact
| Asteroid | A relatively small, inactive, rocky body orbiting the Sun. |
| Comet | A relatively small, at times active, object whose ices can vaporize in sunlight forming an atmosphere (coma) of dust and gas and, sometimes, a tail of dust and/or gas. |
| Meteoroid | A small particle from a comet or asteroid orbiting the Sun. |
| Meteor | The light phenomena which results when a meteoroid enters the Earth's atmosphere and vaporizes; a shooting star. |
| Meteorite | A meteoroid that survives its passage through the Earth's atmosphere and lands upon the Earth's surface. |
The interaction of small asteroids in the Earth's atmosphere
Meteoroids falling in the ocean would create great
tsunamis
(enormous waves), destroying coastal lands, heating the ocean
and introducing water vapor into the atmosphere. Crater
Animation
The lighter material thrown high in the atmosphere would heat
up as it re-enters. Dust left in the atmosphere
would block sunlight, now cooling the surface. This 'nuclear winter'
would kill vegetation which in turn would kill off species
dependent on vegetation.
The atmosphere's chemistry could change drastically, creating
acid rain. The impact, if large enough, could disturb the Earth's
mantle, creating enormous lava flows.
Depending on the size of the meteroid, what its made up of and
the angle it hits the earth's atmosphere, a meteoroid can reach
different zones of the atmosphere. Small meteoroids hit the
earth all the time, but never reach the ground. The collisions
between free atoms and air molecules in the atmosphere produce heat,
light and ionization, i.e. a meteor, usually evaporating
the meteoroid. See diagram of different kinds of phenomenon
Here.
Meteoroid velocities: about 30 km/s (about 30x a bullet).
Large meteoriods throw material up into and above
the atmosphere, and is highly heated during re-entering,
sparking fires.
Typical ejecta fall within a diameter or two
of the crater. Larger debris will make their own
secondary craters.
