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Re: extinction6
>THE MECHANICAL ENERGY OF THE OBJECT
>If
>m = 2000 Gt
>( V = 500 km3 and specific gravity is 4 g/cm3)
>and
>v = 5 km/s
>then E = 2xe15x1.25xe7 = 2.5xe19 KJoule
The velocity is impossibly low. The range of possible impact velocities
between an object in a heliocentric orbit and Earth is from 11 to 72 kms-1.
Asteroids (and related objects) which usually move in orbits with
relatively low eccentricities and inclinations tend to lie in the lower
part of the register and comets in the higher part. Typical speeds for
meteorites are 15-20 kms-1, so Your energy estimate is about an order of
magnitude too low.
Another thing: chondritic objects can contain as much as couple of percent
of sulfur. This is mostly in the form of sulfides which readily oxidate to
SO2 under impact conditions, thus contributing significantly to sulfate
aerosol production.
Tommy Tyrberg