18
What is a
crater?
•Must
think of them as caused by very large explosions from release of kinetic energy of impactor
–Like
a mortar shell – it isn’t the size of the shell which
matters,
its how much energy you get out of the explosion
its how much energy you get out of the explosion
–DO
NOT think of them as just holes drilled into surface – think EXPLOSION
–Kinetic
Energy E = ½ m v2
–v is roughly escape speed of earth
–m = mass = volume * density (Consider
a 1 km asteroid)
–E
–This
is ~4500 ´ the size of the largest (~50 Mt) hydrogen bombs ever built
and this is for a relatively small size asteroid
and this is for a relatively small size asteroid
